[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference napalm::commusic_v1

Title:* * Computer Music, MIDI, and Related Topics * *
Notice:Conference has been write-locked. Use new version.
Moderator:DYPSS1::SCHAFER
Created:Thu Feb 20 1986
Last Modified:Mon Aug 29 1994
Last Successful Update:Fri Jun 06 1997
Number of topics:2852
Total number of notes:33157

770.0. "Effects - Reverbs & Compressors" by DREGS::BLICKSTEIN (Dave) Fri Apr 24 1987 21:03

    Anyone have any experience with ART or Audiologic components?  I've
    never heard of them before.
    
    I'm looking to get a compressor/limiter, a stereo reverb unit, and a 
    stereo DDL with presets, all rack mountable.
    
    The folks at Daddy's in Manchester have recommended the ART Proverb
    ($349) which is reverb/ddl with presets, and the the Audiologic
    compressor/limiter at $269.
    
    He has also recommended the Roland DEP-3 and DEP-5.
    
    I'm going to check em out in person sometime next week, but I'm
    really not sure how to evaluate these kinds of things (particularly
    reverbs and compressors - but I do know a lot about DDLs cause I
    use my ADM-1024 constantly and love true stereo DDL effects and
    other DDL "tricks").
    
    I was planning to get an SPX-90 but the guy at Daddy's (who DOES
    carry them) says that they do a lot, but they don't do any one thing
    very well even though they do a lot of things.
    
    Has anyone found MIDI programmability to be very important?
    
    What exactly is stereo reverb from a mono source?  (i.e., how are
    the channels different?)  Is this important?

    	db
T.RTitleUserPersonal
Name
DateLines
770.1......2 centavos.....JON::ROSSwockin' juanFri Apr 24 1987 22:5930
    
    Check reverbs with some different sources: vocal, percussion,
    (what else guys?) Id check piano, lead synth.
    
    Elecronic music reviewed the ART reverb somewhat favorably
    (for low end $$$) and made a big point that certain "settings"
    (really algorithms) sound either good or bad depending on the
    input SOURCE. (see above).
    
    Basically dig. reverbs use high speed math on the digitized
    in values where some terms are delayed by sample times
     (read: delay line taps). Some "equations" (algorithms /programs)
    calculate 2 results instead of one and viola, stereo from 
    a mono input source. No reason why the program couldnt handle
    quadraphonic or n-phonic stereo images, but who has the amps and
    speakers (or mixers!) for that, eh?
    
    I think that for most users, being able to SWITCH presets, via
    midi (or, ok, footswitch) is useful and easy. Dont see a need
    for programming the parameters of the presets via midi or computer
    (hey how many 'reverbs' do you really need!???), but then.....

    I can copy the ART review for you. Think keyboard did one too (?)
    
    OH. ONE more thing to look for is obvious "looping" sounds in the
    reverb. Er, and try a small soft signal (or listen to decaying
    sounds) and try to hear the amount of quantization 'gritty' noise.
    
    I defer to Len here.
     
770.2BARNUM::RHODESMon Apr 27 1987 12:5212
    I just read in the usenet that the SRV-2000 is now on sale for $399
    at Sam Ashe music in NYC.  This unit has been discussed numerous
    times in this conference, and seems to be the clear digital reverb
    winner for sound and programmability.
    
    I would also like to point out that 99% of the digital reverbs on
    the market are not true stereo (ie they only accept one input channel,
    or mix the two input channels).  Let's face it.  Doubling the number
    of channels means cutting the sampling rate for each in half.
    
    Todd.
770.3can't help with the reverbMELODY::DEHAHNMon Apr 27 1987 13:0115
    
    I've heard good things about the Audiologic compressor, although
    I've never sat down with it and played around.
    
    I was looking for a top quality (well, almost) compressor/limiter/noise
    gate a while back and considered a lot of brands. After looking
    for about a month, on the glowing advice of Mr. Feshkens I went
    with a Symetrix 525 stereo comp/lim/gate. It's very clean, and when
    you set it up correctly, inaudible. You can gang the two channels
    together for stereo. It uses the Valley People VCA's. I paid $300.
    
    FWIW
    CdH
    
    
770.4Save some $NEDVAX::DPOWELLMecca-lecca hi, mecca hiney hoMon Apr 27 1987 13:057
    The ART Proverb can be had for $299 from 
    Music Emporium 
    8101 Cessna Ave
    Gaithersburg, Maryland 20879
    (301) 869-5804
    
    Dan
770.5Valley People? JON::ROSSwockin' juanMon Apr 27 1987 13:277
    
    Check note on mail order dealers. Might beat that price...
    
    Um, "Valley People VCA's"? 
    
    Who they??? Can we get just the chips?
     
770.6OK, Let's Get StereousDRUMS::FEHSKENSMon Apr 27 1987 18:0417
    Don't have much to add, but an SRV for $399 is a steal.
    
    The SRV is a *true* stereo reverb, it computes two separate reverberant
    fields from its single input.  Watch out for some stereo reverbs
    which only phase invert and filter the output to produce a pseudo
    stereo effect.  A common stereoization trick is to route the signal
    through two slightly different comb filters (easily made from two
    delay loops with slightly different delay times, usually possible
    in a reverb unit without too much extra hardware/software).
    
    Most inexpensive reverbs with stereo ins and outs sum the inputs,
    send them through a single reverb, pseudostereoize the reverb's
    output, then mix that with the original ins to provide the stereo
    outs.  This usually produces acceptable results.
    
    len.
    
770.7Motor oil is motor oil?DREGS::BLICKSTEINDaveMon Apr 27 1987 19:2723
    OK, I'm tempted by all the accolades that have been laid on the
    SRV and this price.
    
    On the other hand, Sam Ash is selling a unit called the Korg DRV-1000
    for $169.  It is claimed to be stereo (just "how" or "what kind"
    of stereo I don't know).   It has 8 general reverb sounds but there are
    ways to diddle the 8 sounds.
    
    The guys at Sam Ash are willing to sell me either the SRV or the
    DRV at what I would consider to be great prices but they seem rather
    emphatic that the DRV-1000 at $169 is an "incredible steal".
    
    Anyone know anything about the DRV?
    
    Assuming that it is a good digital reverb, are the differences between
    reverbs such that the SRV is worth twice as much?  Is it just that
    the SRV is more flexible?  I mean, I don't really think I need a
    lot of flexibility.  I mainly looking for something with just decent
    semi-realistic sound that won't muddy up things.
    
    Gosh, I'm pretty confused.
    
    	db
770.8Does This Guy Believe, Or What?DRUMS::FEHSKENSMon Apr 27 1987 20:0157
    The SRV is "better" than most of its competition in two respects:
      
    	It sounds better, and
    
    	it has more flexibility.
    
    It sounds better partly because of its flexibility, but also because
    it's designed better - the width and speed of its convertors, the
    precision of its arithmetic processors, the complexity of its algorithms.
    
    It's quiet and the reverb it produces has to be listened to *very*
    closely to be distinguished from the real thing.  I haven't heard
    a DRV, but it would be have to be *perfect* to sound better than
    an SRV.
    
    Do I think that in most applications, most users can hear the
    difference?  No, and I include myself among those users.
    
    So, practically, what you're paying for is additional flexibility.
    Again, I can't speak for the DRV, but the SRV has
    
    	* two completely separate reverb implementations in the same
    	  box
    
    	* 32 program slots
    
    	* 18 (?) algorithms (many of which are admittedly useless - I mean,
    	  who needs to simulate the reverb of a one foot box?)
    
    	* 3 quasi parametric EQs
    
    	* reverbs up to 99 seconds
    
    	* predelay up to 450 msec.
    
    	* control of early reflection density, build up rate, etc.
    
    	* etc. (see my review elsewhere - 5 switch inputs!  etc.)
    
    The SRV was probably overkill when it came out.  Most digital reverbs
    for the "semipro" market have backed off substantially from its
    content (witness Roland's own DEP-5!).  It certainly does more than
    most people need.  If you like programming your own synth voices,
    you might take a liking to the SRV's programmable flexibility. 
    If you use presets a lot, you won't exploit an SRV.
    
    I love mine, I'll never give them up, and even when the lithium
    battery croaks and I have to reprogram them by hand, I'll still
    love them.  Maybe if somebody comes out with a reverb of this quality
    for $100 or less I'll consider replacing or augmenting them.
    
    And I paid almost list price for them.  They were worth it.  They
    still are.  At $400, you can't do better.  You may not need them,
    but you can't beat them.
    
    len.
    
770.9SRV!!!!!!!!!!!!!!!!EMERLD::DUBEDan Dube 264-4373Tue Apr 28 1987 15:4112
Dave,

I couldn't agree with Len more. Buy the SRV - it's a fantastic 
unit. Look at it this way - it's one less item you'll have to 
upgrade in the future! It might be more than you need at the 
moment, but I'm sure you'll eventually outgrow the setup you have 
now. You'll already have a top-notch reverb if you buy the SRV. I 
know nothing about the DRV, so I can't really compare. I do own 
an SRV (I paid $495, and I thought that was a steal), and I love 
it.

-Dan
770.10Another satisfied SRV owner!FGVAXU::MASHIAFast falls flatten flutesTue Apr 28 1987 16:1414
    Just wanted to add another vote for the SRV.  I got mine late last
    year for $495, after researching a lot of others, and it was definitely
    the best for the bread. (See earlier note called REVERBS REVISITED,
    don't recall the #).
    
    It's the only processer in my low-budget home studio, and the only
    thing in it that really sounds professional.  It *is* more than
    I need, but it sure is nice to have. Since you'll end up running 
    everything thru a reverb anyway, despite any other processing,
    I think it's worth it to have a good one.
    
    But let's hear some other opinions!    

    Rodney M.
770.11SRVVVVssssssrrrrrrrrrvvvvvvvvvJON::ROSSwockin' juanTue Apr 28 1987 17:1110
    
    you guys sure youre not on node SRV::

    Ok. I too am happy with the SRV. And feel I havent
    done it justice.
    
    yet.
    
    ron
    
770.12sssproinggggggoingggoinggggDONJON::CROWLEYTue Apr 28 1987 19:569
    
    
    Here's one person who's unhappy with the SRV's.  Unhappy that there
    isn't one in MY studio that is!!  I used one of these beasts in
    the studio several times before.  Unbeleivable sound.
    Damn!!  I already spent my tax check!
    
    ralph (who's getting ready to shoot his poingy spring verb)
    
770.13Me too.REGENT::SIMONETue Apr 28 1987 20:527
    
    Me too!  Bought an SRV about three months back for $499 after reading
    Len's review.  The patch mapping is neat since I don't have a dedicated
    keyboard controller or midi mapper.  And it sounds great.  It has
    a gated-reverb preset which sounds great with my TR707 snare.
    
    Guido
770.14REGENT::SCHMIEDERWed Apr 29 1987 00:2120
Has anyone here tried the SRV2000 on acoustic instruments such as horns?  Or on
the human voice?  Or anything else that might test the machine more than an
electric instrument?

Many people think 18KHz is full bandwidth.  Well, I don't claim to be a "Golden
Ears" but 18KHz isn't good enough for these ears.  At least, on acoustic
instruments and most percussion.

I am thinking of buying an SRV2000 or SPX90 Model B later this year.  Although
I don't hesitate to admit that I LIKE spring reverbs...on jazz guitars, at least
(I also don't hesitate to admit that I DESPISE them on vocals!).

A major drawback for me is the human interface.  Users would know more about
this, but my perception is that it isn't all that easy to use in real-time.
Since I primarily play these days and don't spend much time on mini-studio
functions, I have no desire for another piece of hardware that takes mucho time
to program, alter or just plain use.


				Mark
770.15Too poor for an SRV.NIMBUS::DAVISWed Apr 29 1987 17:3824
    One suggestion, if you're interested in the low end of the reverb
    market, is the Microverb from Alesis. I picked one up about a month ago
    and am very happy with it. Haven't had a chance to check it out in a
    real high grade studio setup, but it sounds real good recorded on tape
    and played thru my home stereo. It's 16 preset only, 6 small rooms, 7
    large rooms,, 2 gated, and a reverse, but that's actually a pretty good
    selection. Has 16 bit resolution and the simulated type of stereo
    outputs discussed earlier in this note (sounds nice). I paid $225, but
    I'll bet you could find it for under $200 now with a bit of bargain
    shopping.
    
    One thing to consider (especially if you're doing "virtual" MIDI tracks
    instead of mucho multi-track) is that it's real nice to have more than
    one reverb. The same setting that sounds awesome on your snare drum may
    sound terrible on a voice or string patch. At $200 you could buy 2
    Microverbs for the price of one SRV (which of course is just what
    Alesis suggests in their literature, they show a diagram of how 8
    reverb settings might be used in a typical rock/pop mix). And if you
    decide to upgrade to a better 'verb in the future, you wouldn't
    necessarily want to get rid of the Micro. 
    
    Rob
                                             
770.16I would think stereo inputs are importantDREGS::BLICKSTEINDaveThu Apr 30 1987 14:0432
    I just read a review of the ART Proverb.
    
    I was surprised to find that it had stereo inputs.  Now, if the
    stereo outputs are at least fairly discreet, I would consider that
    to be a big advantage over the SRV.  It has 99 presets some of which
    include some standard stereo delay sounds (flanging, chorusing,
    etc.) which makes the thing even more useful.
    
    One question I'm trying to answer is "how could I use a reverb without
    stereo inputs".   Almost all the stuff I have is stereo and some
    experiments I've made have demonstrated that recording them in stereo
    is a BIG win.
    
    So the question is how do I produce reverb for a stereo signal?
    Well, the best suggestion I've got so far was from Ron Ross who
    suggested that I combined the stereo inputs of the instrument and
    run the combined signal out to the SRV.  Eliminate the direct signal
    from the SRV outputs and then mix the stereo reverb back in through
    the effects return.
    
    That would probably work ok.  I expected that there would be some
    crosstalk (especially on things like gated reverb).  It does use
    up my effects send (I only have one on my Yamaha MT1X, and I need
    it's return to act as "channels 5 and 6".   It also makes it a bit
    difficult to combine with other stereo effects I have (I won't go
    into that - just think about how one would go about wiring that
    up.)
    
    It just seems like I'd get better results with a reverb with stereo
    inputs.  Are there any tricks that I'm missing?
    
    	db
770.17Not enough sends, mon !16514::MOELLERrecycle your used PERSONAL_NAMEsThu Apr 30 1987 17:299
770.18Wow, 14 "channels" for $325DREGS::BLICKSTEINDaveThu Apr 30 1987 17:5312
    Hey Karl,
    
    Wanna sell your mixer?
    
    I don't think I could expect to get a mixer like that at the price
    you mentioned, but would love to hear that I could.  No question
    but that eventually I am going to need to get a mixer to help my
    MT1X 4 track.
    
    3 mono sends with stereo returns would do me jus' fine!

    	db
770.19sorry I'm usin' mine, getcher own16514::MOELLERrecycle your used PERSONAL_NAMEsThu Apr 30 1987 18:465
    re -1.. you, too, can own one of these black plastic beauties..
    Yamaha KM08 mixer, that's $235, not $325 !! the only drawback is
    that it's not a multibus mixer - no tape in/inst in switch per channel.
    
    so what! karl
770.20I *NEED* a 20-600mm f/1.4 zoom that weighs 4 oz.DRUMS::FEHSKENSThu Apr 30 1987 20:5527
    Two observations:
    
    re 18 KHz bandwidth not being adequate - well, yeah, it would be
    nice to have more bandwidth in the reverb path, but I seriously
    doubt you're going to hear a difference.  Most natural reverb has
    such a strong high frequency damping that there's not a whole lot
    of energy in the reverberant field at 18 KHz.  Sorry Mark, I have
    to characterize this concern as a red herring.  Be that as it may,
    if you can find a reverb with wider than 18KHz bandwidth for the
    reverberant field for less than $5K, more power to you.  Note that
    the SRV's bandwidth for the *direct* signal is probably in excess of
    30 KHz.  And it's 18KHz spec can't be touched by any of the reverbs
    we've been talking about.
    
    re the need for separate stereo inputs - this too strikes me as
    an unrealistic requirement, for two reasons - first, most stereo
    sends *from a single instrument* are not characterized by dramatic
    separation, but rather by a spread field, so a little "leakage"
    through the reverb path is likely to be undetectable except via
    very carefully set up tests; second, reverberant fields are by their
    very nature not highly localized, and again, are more
    characteristically spreads than distinctly different sounds.  If
    it's absolutely imperative that you keep two distinct reverberant
    fields utterly isolated, multitrack. 
    
    len.
    
770.21REGENT::SCHMIEDERThu Apr 30 1987 22:0333
Well, Len, I didn't realise the specs were just for the altered signal.  If 
the direct signal has a range of >30KHz, that's generally sufficient for most 
home recording systems.  It isn't so much that one hears or feels the 
frequencies above 18KHz as that distortion or clipping above those frequencies 
generally affects the next octave down as well, which IS in the audible range. 
 This is why Magnavox's quadruple oversampling sounds more "musical" to 
afficionados of acoustic music than the more typical Sony method of double 
oversampling, in CD players.  It has to do with the REAL meaning of those 
specs on dynamic range/etc.  Clipping does nasty things to the rhythmic pull 
of the music, as I discovered when I picked up the remastered "Kind of Blue" 
album (Miles Davis).  I don't think your ears are any less "golden" than mine 
that you wouldn't notice such a problem on the SRV-2000 if it existed, though.

I always run blindfold tests on myself when I test out equipment.  I never use 
specs to choose what to buy, but sometimes use them to filter out inferior 
equipment to narrow down the field of choices.

This ART ProVerb sounds more interesting now.  I'm not inclined to make fast 
purchases as I once was, and am spending as much time as it takes to find the 
unit that is right for me.  Since I'm mostly playing and not recording these 
days, that gives me the luxury of patience.

The Yamaha SPX90 Model B is said to be functionally the same, but higher in 
price and with much better specs.  Not sure how the earlier version will be 
upgradeable by the owner, if that's the case.

I have never had all the necessary equipment to really take advantage of 
stereo effects, but feel that's more a performance than recording issue.  I 
know some professional bassists who would just DIE if they had to go on stage 
with only one amp, though.


				Mark
770.22About Face!!!!DREGS::BLICKSTEINDaveFri May 01 1987 14:07101
    OK, I warned you guys that I changed my mind hourly, so don't be
    surprised by any of the following:
    
>  I have never had all the necessary equipment to really take advantage of 
> stereo effects, but feel that's more a performance than recording issue.  I 
> know some professional bassists who would just DIE if they had to go on stage 
> with only one amp, though.
    
    If we're talking about reverb, I think stereo is almost entirely
    a recording issue.  However for things like chorusing and flanging,
    stereo makes a big difference both in recording and performing.

> This ART ProVerb sounds more interesting now.
    
    OK, last night I checked out the ART Proverb and the SPX-90.
    
    The conclusion I came to about the ProVerb is that it is very suitable
    for recording but not for performing.  It has NO remote control
    (not even remote "bypass")features and it is time-consuming to go from 
    one preset to another unless they have preset numbers that are close 
    together (note that you can't reorder the presets, they are
    "hard-wired").  Another nit to pick is that it only has MIDI in, no
    MIDI thru.  This should be illegal and subject to fine.
    
    It had excellent audio qualities and the stereo effect was quite
    dramatic (I A/B-ed it with mono).
    
    Although I haven't been able to "play" with one yet, I think the
    MIDIverb II would be a better choice than the ART Proverb.  It has
    more performance features and according to most people is quieter
    (it was hard to tell the noise level of the thing in the situation
    I was at in the store (running it through a cheap mixer, and then
    through cheap "Mouse" type speakers.   Also, the half dozen or so
    teenage guitarists playing "Eruption" made it somewhat hard to hear
    at times).
    
    Onto the SPX-90.  I think this is a fantastic unit.  I am going
    to buy one, but I am going to wait until the Mark B comes out.
    This thing does everything "pretty well" and has EXCELLENT performance
    features.   It's definitely a winner.  It doesn't do compression
    as well as a dedicated compressor, same for limiting, same for
    harmonizing, etc.   However, I thought this unit had excellent reverb
    sounds but as I've said, it was hard to tell in the environment
    I was checking it out in.  It did seem to have a small amount of
    noise though.  The compression features were too "noticeable", in that 
    you could "hear" them "kick in" - the good compressor/limiters I've 
    tried didn't have that problem).
    
    So if it doesn't do anything as well as a dedicated unit, why get
    it right?  Well, it has been mentioned several times that having
    two reverbs, or two compressors, or whatever is often very handy.
    I liken this unit to the concept of the "6th man" in basketball.
    
    What it does for me is:
    
    	o Give me an extra reverb or compressor, or DDL when I need
          it.
    
    	o Give me a whole lot of things I want to have but don't,
          particularly a harmonizer, reverse gating, etc.
    
    	o Give me a unit that is VERY well suited for live performance.
          With the optional foot contoller you can even set up "chains"
          (sequences of programs).  Also you can "queue up" a program
          while another program is still running (i.e. changing the
          preset number does not take effect until you hit "recall").
    
    Yep, this one's a real winner.
    
    So you may be asking.  What have I decided to get:
    
    Well, surprise..... I'm gonna get an SRV-2000! (Assuming Sam Ash
    has any left), but when the SPX-90 Mark B comes out, I'll get one
    of those also.
    
    Basically, everywhere I go people say "SRV-2000, SRV-2000, SRV-2000".
    Even the goddam salesman at Daddy's WHO DOESN'T EVEN HAVE ANY MORE
    TO SELL!!!!   OK, I give up.  I'll get one.   I also came to the
    conclusion that NOT getting one in order to save on effects sends
    on my mixer isn't really a good reason.
    
    Regarding my former opinion on stereo inputs, I STILL think that
    this is very handy and important, and it was STUPID not to put them
    on the SRV-2000, but that unit has too many other features to
    compensate for that one mistake.
    
    I still don't know what I'm gonna do regarding compressors.  Daddy's
    is selling the Yamaha GC2020B for $319 which is a darn good price
    (and I'll bet they might even go a bit lower (Sam Ash wants $350
    for that unit)) but Fritz at E.U. Wurlitzer says Yamaha compressors
    aren't very good, but then he doesn't carry them.  I've got a GC2020A
    on loan and am gonna check that out.  If I like it (compared with
    units that Fritz DOES sell), I'm going to presume that Fritz has
    been "infected" by the EU mentality and just write that place off
    my list.

    Sigh.  You could read this note with all its techo-jumble and have 
    ABSOLUTELY NO IDEA that it is in the least bit related to music or 
    art!  That really bothers me.
    
    	db
770.23What is the REAL price?PIXEL::COHENRichard CohenFri May 01 1987 14:355
    I just called Sam Ash and they want $425 for the SRV-2000. Maybe
    the $399 is only for walk ins?
    
    	- Rick
    
770.24hey, just for fun....JON::ROSSwockin' juanFri May 01 1987 17:3410
    
    Try Thouroughbred Music for fun.
    Roland distributor. 813-237-5597
    Price included shipping. COD.
    
    The other good roland place seems to be:
    Rhythm City 404 237 9952. You can usually
    get them to ship COD for $5 or so more.....
    
    
770.25REGENT::SCHMIEDERFri May 01 1987 19:156
So, are there any good compressors on the market for bass guitars?  There are 
some that are OK for vocals but not for bass.  The only good one I've ever 
heard that didn't noticeably kick in was hand-made and not for sale.


				Mark
770.26Not to be limited by compressionDREGS::BLICKSTEINDaveMon May 04 1987 17:3521
    OK, so I've resolved the reverb issue.
    
    But almost no one has talked about compressors?
    
    What's out there?  What's good?  How much is it?  What do people
    have?  What do they use it for?
    
    The reason why I feel I *need* a compressor is that everytime I
    try to record something that's being mic'ed (instead of direct),
    it almost sounds like someone is moving the mic around, causing
    the thing to fade in and out very quickly.   I get this effect for
    guitars and vocals.  Guitar parts sound very uneven on the playback
    and notes just seem to get lost.
   
    Although I don't consider it quite as urgent, I know that limiting
    will help to in that for certain things (oddly enough, ESPECIALLY
    things recorded direct), I get spikes which produce a noticeable
    unpleasant breakup of the sound.  Sorta like turning up the bass
    to loud on my crummy car stereo.
     
	db
770.27Review of Yamaha GC2020A compressorDREGS::BLICKSTEINDaveTue May 05 1987 04:2292
    OK, I just got through checking out the Yamaha GC2020A.
    
    Note that the 2020A has been replaced with the GC2020B.  I do not
    yet know what the differences are between the A and the B but if
    I find out I will post.  Daddy's is selling the 2020B for $319.
    Sam Ash is selling it for $350.
    
    First thing I have to warn you about, is that this is the first
    compressor/limiter I have ever played with (other than a cheap little
    BOSS box I picked up about 10 years ago to get more sustain from
    my guitar).   I can not compare the GC2020A to anything, I can only
    give my impressions of it.
    
    I found the unit to have a very high level of noise.   I do not
    think it could be a line problem because hitting the bypass switch 
    cut out all the noise.  Also no amount of fooling with the input
    and output levels really helped.  I tried it with 3 kinds of inputs
    (direct guitar, mic'ed voice (medium impedance (i.e. crummy) mic), 
    and keyboard inputs and had the same level of noise each way.  Would
    have been interesting to try it with nothing plugged in but I only
    thought of that AFTER I had repacked the unit, and shut down and
    unplugged all the stuff.
    
    Another criticism I had was that the unit gives you no help in setting the 
    input level.  The only meter on the unit tells you how much compression
    is being applied.  I like units that tell you when the input level
    is too high, but few devices seem to come with line level meters
    these days.  I just played around with the levels until I got the
    best sound.

    As to the sound, it's hard for me to say.  It sounded excellent
    for low to medium compression levels but somewhat thin and edgy for
    high to infinite compression levels.  This may just be a normal
    property of the effect and not a flaw in the unit.  For this reason
    I didn't discount the unit.  For mic'ing vocals it seem to do the
    job real well (except for the noise).
    
    The Yamaha had been criticized by a non-Yamaha dealer has having
    a noticeable "kick in" when the threshold level is reached.  I don't
    think this is a valid criticism.  You can control (to a large, but
    not complete extent) just how abrupt the compression comes in AND
    out with the "attack" and "release" controls.  I found that with
    a little experimentation, you can set these controls such that the
    application of compression isn't very noticeable.
    
    Controls:
    
    o Input level 

    o Output level
    
    o Expander Gate - this is a noise gate.  I.e. you set a minimum
      	signal level and if the input falls below that level, the outputs
        are muted.  Very handy feature for a compressor (particularly
        this one).
    
    o Threshold - sets the level ABOVE WHICH compression is applied.
    
    o Compression ration - sets the ratio of compression of input to
         output.  A compression ratio of 2:1 means that for a given
         change in the input level, the output level will change only
         half as much.  Variable from 1:1 (no compression) to 1:oo
         (infinite compression: no matter how high the input signal
         gets, the output level stays the same).
    
    o Attack - determines how long it takes before the full amount of
         compression is applied once threshold level is exceeded.  Variable
         from 0.2 ms to 20 ms.
    
    o Release - determines how long it takes for the amount of compression
         to return to zero once the input singal falls below threshold.
         Variable from 50 ms to 2 sec.
    

    The unit is completely stereo (two discreet channels, each with
    its own set of controls).  There are two modes: stereo and mono.
    In stereo mode equal compression is applied to both channels in
    order to maintain a proper stereo image.  In mono mode, you get
    to completely independent compressors.
    
    The amount of compression applied can be determine from an alternate
    input source.
    
    Two kinds of input and output jacks are supplied: 1/4 inch phone
    jacks and RCA pin jacks.
    
    Specs: 
    	Freq. Response: +2dB, -2dB, 20Hz ~ 20kHz
    	THD: < 0.03%
    	Noise level: < -87dB
    
    	db
770.28Thoroughbred's price on SRV-2000ODIXIE::OSTERMANLarry OstermanTue May 05 1987 06:1213
    re .24
    
    I live in Tampa, so I walked in to Thoroughbred to check out their
    price on an SRV-2000.  The salesman tells me it lists for $1499,
    they sell it for $599.  I tell him that Sam Ash sells it for $399.
    "I'll be right back", says he.  Upon his return, he tells me that
    the "owner" can't go below $499, and that he called Sam Ash, and
    was quoted $499!  I didn't call him a liar to his face, but said
    I'd call myself.  I did so, and was quoted $399 immediately.
    
    If a merchant will lie about his competition's prices, he'll
    probably lie about the features of the equipment, too.  Personally,
    I'm willing to pay a little extra if I'm not treated like a fool.
770.29who knowsJON::ROSSwockin' juanTue May 05 1987 13:5813
    
    WHAT?
    
    Ive always gotten low prices from Thoroughbred.

    But that was mail order. I know that when you 
    call manny's or ash in new york and ask for
    keyboard prices, the first thing they say is
    "where are you calling from?'"
    
    Maybe they can give lower quotes if non-resident?????????????????

    The point is that you have to shop around. So buy it from Sam.
770.30SRV-2000 provides excellent "room service"DREGS::BLICKSTEINDaveThu May 07 1987 14:1333
    Just got the SRV-2000 last night.
    
    Plugged it in and tried it out (was too anxious to wait and read the
    manual first, but I ask you: who among us has that kind of patience?)
    
    First thing that struck me was how heavy and large the thing is!
    
    Anyway, I was very impressed.  I had heard one before (Ron Ross gave
    me a demo) but through a bass amp with inputs from a drum machine
    and a crummy mike.  Last night I did some experiments with mic inputs,
    guitar inputs, keyboard inputs, drum machine inputs, and ran it through
    a discreet stereo amplifier (my new Roland JC-120 (boy I sure do seem
    to be getting a lotta Roland stuff - do they have a public stock 
    offering?)
    
    My audio impressions were that I got a very definite sense of a "room"
    that I hadn't with other reverbs I had experience with: my Boogie's
    spring type reverb, the reverb on my JC-120 (which I think uses some
    kind of latch-type system), the SPX-90 reverb, and the ART Proverb.
    I call the thing my "dial-a-room".
    
    I mic'ed my classical guitar and ran it through the SRV and then through
    some headphones, and it really sounded like I was playing in a small
    hall (much more so when I ran it in stereo than when I pulled one output
    and tried it in mono).   I had a blast just playing for awhile like that.
    Almost expected applause at the end of each piece, but got none of course.
    (Not even from the 9-year-old future guitarist who was listening.)
    
    I'm glad I got it.  You guys were right.  A really fine piece of equipment
    is a joy (like my Boogie) and when you can have one for $400, well, every
    so often you gotta treat yourself...
    
    But I *STILL* say it was a mistake not to give it stereo inputs!
770.31Geez, I didn't know yer guitar was stereo...BAILEY::RHODESThu May 07 1987 14:372
 
    
770.32MXR dyna-comp maybe ?GIBSON::DICKENSDistributed System ManglementThu May 07 1987 15:2012
    re .26
    
    Not to make the obvious overly obnoxious, but the lowly MXR dyna-comp
    was designed with guitar and bass compression in mind.  With a good
    power supply it's not all *that* noisy, either.
    
    I got mine (the improved version with the LED indicator) for $25.
    They're discontinued years ago so they'll be *real* cheap when you
    can find 'em.
    
    					-Jeff
    
770.33My guitar *is* stereoDREGS::BLICKSTEINDaveThu May 07 1987 17:4710
    re: .31
    
    > Geez, I didn't know yer guitar was stereo
    
    Actually, my guitar *is* stereo.
    
    However, I was referring to the stereo simulation produced by the
    SRV-2000.
    
    	db
770.34hope this helpsMELODY::DEHAHNThu May 07 1987 17:4828
    
    Re: VP VCA's
    
    Sorry about the delay (arf arf) I've been on vacation. Valley People
    produce a line of high end studio gear, mainly compressors, limiters, gates,
    stereo generators etc, similar to the offerings from Urei or Orban. 
    They make the Dyna-mite compressor, and Kepex comp/exp/gate. I guess
    they made some kind of licensing agreement with Symetrix to sell
    them their proprietary VCA. I don't know if they're available on
    the open market. 
    
    The Symetrix 525 suits my needs perfectly (sound reinforcement),
    it's simple and easy to use. It doesn't have adjustable attack/release,
    it sorts that out by itself throughout the range of compression
    ratio. The gate is audible when working hard if you set it to -40db,
    but if you use it sparingly it's quite effective. As for noise,
    I haven't heard any unit that doesn't have some kind of audible
    noise floor. The trick is to make the tradeoff between audible gating
    and reduced noise. It takes a little adjusting but once it's set
    you leave it alone.
    
    I believe that Symetrix makes a stereo unit like the 525 but with
    adjustable attack/release, but I'm not sure since I bought mine
    over a year ago.
    
    CdH
    
    
770.35S501 Discussed ElsewhereDRUMS::FEHSKENSMon May 11 1987 17:439
    Somewhere in this conference is a discussion on compressors which
    includes full specs of the Symetrix S501 compressor/limiter (the
    one I have - I posted the specs) and another compressor.  I like
    my S501, I have never been able to hear it in action (except of
    course for its desired effect).  It is a mono unit but can be linked
    to another for stereo use.
    
    len.
    
770.36REGENT::SCHMIEDERMon May 11 1987 17:599
RE: .35

I have never heard of Symetrix, Len.  Where did you buy yours?

I don't think stereo is a big factor for me in compression, since I wouldn't 
use it as an effect per se.


				Mark
770.37Depends on How You Use ItDRUMS::FEHSKENSMon May 11 1987 18:027
    Symetrix is a pretty big name in effects.  I got mine at EUW.  The
    stereo feature is for two track use and syncs the two compressors
    so compression doesn't radically alter the apparent placement of
    sounds.
                     
    len.
    
770.38Pssst, bud.... wanna buy a "used" effects send?DREGS::BLICKSTEINDaveMon May 11 1987 19:2841
    re: .37
    
    Gee Len, if there was a market for add-on effects sends, you'd make
    a fortune in commissions.  ;-)
    
    You tell me, "get the SRV-2000 Reverb... it doesn't have stereo
    inputs but you can do what you need to do with effects sends".
    So I get an SRV-2000.
    
    Now you're saying "get the Symetrix", which is also mono.  Guess
    how I got process a stereo signal if I do?  You got it: effects
    sends.
    
    Hopefully (Len) you realize I'm just kidding.  I'm very grateful
    for the advice you given.
    
    Actually, for my uses, mono is just fine.  My only planned usage
    is to level out mic inputs.   I don't need another effects send
    for this but it limits me to recording one mic at a time, but I 
    don't see that as a problem.

    One thing I have thought about doing with compression is to use
    it to bring out the vocals.  You can do this by using the vocal
    inputs to control the compression level, but actually compressing
    the background.  The general idea is that when the vocal signal
    is present, the compressor automatically backs down the background
    and then brings it back up when the vocal signal drops below the
    threshold.
    
    This is an idea I had and once again I have to qualify it with the
    declaration that it may be one of the following:
    
    	a) stupid (why the hell would you wanna do that?)
    	b) obvious (people do this "trick" all the time)
        c) Naive (can't be done)
    
    I think it can be done, but the trick is to not have it be too
    noticeable.  It either has to be very slight, or very gradual.
    
    BTW, here is *THE* solution to guitarists who play too loud right?
    Just run 'em through a compressor controlled by some other input.
770.39JUNIOR::DREHERPlatitudes and Folklore...Mon May 11 1987 20:0711
    Re: .38
    
    Dave, the answer is (b), it's done all the time.  This effect is
    called 'ducking' and is used mainly on commercials for the voice
    overdub over the music.  While the announcer talks "Big savings
    for Mother's Day at...", the background music lowers in volume.
    
    Also, if you're looking for mono compressors you might also check out
    the dbx 160x.  I have one.
    
    Dave
770.40Pointer to MoreDRUMS::FEHSKENSMon May 11 1987 20:345
    See note 373 for more on compressors/limiters, and 373.5 specifically
    for the S501 specs.
    
    len (who only pays for stereo when he really needs it).
    
770.41God bless rack mountsDREGS::BLICKSTEINDaveMon May 18 1987 14:4037
    Hey KM,
    
    I checked out the Yamaha KM08 mixer this weekend.  Awesome features
    for the price!  3 MONO-out/stereo-return effects sends!!!
    
    Daddy's in NH wants $299 for it.  I told them I'd write them a check
    a check and walk out with it for low $200's, but they wouldn't bite.
    I'll check around some other places.
    
    One general question: does anyone know of anything similar to this
    in the same general price range?  Ideally, what I'd like to have
    is a KM08 in a rack mountable style?  Does such a thing exist?
    Yamaha makes a MV802 that's rack mountable and very similar to the
    KM08 but it only has 2 effects sends and is $445.  It has also has
    a few things that the KM08 doesn't have like a limiter and mic style
    outputs for plugging directly into a PA in addition to stereo monitor
    outputs (and phones).
    
    I'm not sure the 3rd effects loop is all that important, but the
    extra $125-$225 is.
    
    I'm sorta reluctant to buy yet another non-rackmountable item. 
    It means:
    
    	1) Something else that I have to get a case for
    	2) Something else that needs to be set up each time
    	3) Something else that I have to find a place to put
    	4) Something else that's is probably gonna have to be out of
    	   convenient reach
    	5) Even more messy/noise-introducing long cables, etc.
    
    God bless the guy who invented rack mounts.
    
    	db
    
    
    
770.42go with it IN or ON the rack:JON::ROSSNetwork partner excited first tryMon May 18 1987 17:5813
    Got my 802 from profound. $225 as I remember.
    
    I leave it wired to the stuff in my rack and 
    basically put it INSIDE the rack in an empty
    space for transport, and pull it out and
    place it on the rack top at eye level for 
    performance.
    
    Made 'special' (read:short) cables to minimize
    the mess when inside the rack....
    
    nice. 
    
770.43An interesting, cheap 8-channel rack mount mixerDREGS::BLICKSTEINDaveMon May 18 1987 21:4727
    OK, there may not be a Santa Claus Virigina, but there is something
    very similar to the KM802 in a rack mount, and if you can believe
    it, it's seem to be going for a little less than a KM-802.
    
    It's the Kawai MX-8R.  It's brand new, and EU quotes $279 over the
    phone for it (they quoted me $299 for the KM-802).
    
    Kawai MX-8R vs. Yamaha KM-802:
    
    o MX has 3 position adjustable input levels on all channels.
      Inputs are adjustable only on two channels on KM.
    
    o MX is rackmountable.  MX takes up TWO rack spaces (I'm told that
      this is a BENEFIT because the knobs are not as closely packed
      together as they are on some units which makes them hard to
      adjust quickly.
    
    o MX has two effects sends with stereo returns.  KM has 3.  However,
      MX effects send can be pre or post mix (very handy).
    
    I'm not sure of what other differences there are.  I know the KM
    DOES have a phone jack, have no idea if MX does.  I know that many
    rack-mounted mixers have both 1/4" phone plugs (for monitor) AND 
    mic-outputs (to go direct to the PA) but I don't know if MX has
    this.
    
	db
770.44Simmons MixingMINDER::KENTTue May 19 1987 07:3110
    
    re .-1
    
    I saw a review recently of a machine which Simmons (The Drum People)
    make which may fit the bill. The big plus was that it is midi'd
    and you can store mixes recallable by patch changes. Didn't sound
    too expensive either (300 pounds ?)
    
    					Paul.
    
770.45yeabutJON::ROSSNetwork partner excited first tryTue May 19 1987 19:0416
    
    Hey, good. If the kawai is under $230 mail order.
    
    Did I hear right that the Kawai has teensy pots
    and not the more 'legible' (at least from 2 feet
    away on stage) large slide faders?
    
    Other than that it sounds great. I have no need for
    separate level controls on the other 6 of 8 channels
    since I use synths. If you use mics, ok, thats an advantage.
    
    Someone can help me out with the pre/post feature...
    
    do they have one in stock? lets go hear/see it!
     
    
770.46Full review of Kawai MX-8R keyboard mixer featuresDREGS::BLICKSTEINDaveTue May 19 1987 19:3587
    OK, the MX-8R is even hotter than I thought.
    
    Here's a more detailed run-down of the device:
    
    Input section
    -------------
    o 8 inputs
    o EACH input has a 3 position gain adjustment switch (L-M-H)
    o Each input has a clipping indicator
    o Each input has both 1/4 inch and RCA type input plugs
    o There are NO EQ features on this unit!!
    
    Output section
    --------------
    o Stereo
    o 3 kinds of outputs!!!  XLR (to PA), 1/4 (to monitor amp), and
      RCA (to tape)
    o Phone jacks (I guess there are 4 kinds of outputs
    o Level leds for L and R output monitoring
    
    Effects
    -------
    o two mono-send/stereo-return effects loops
    o One effects send is switchable between pre and post mix
    o Both effects sends can also be used with mono effects
    o There is NO volume control on the return
    
    (Are you ready for this!!!)
    
    MIDI
    ----
    o No, it does NOT have MIDI controlled mixing although there are
      some recording mixers showing up with that.  What it does have
      though is builtin pure MIDI through box with 1 IN and 3 THRU's.
      That actually makes a fair amount of sense when you think about it.
    
    Size
    ----
    o 2 standard rack mount spaces
    
    Price
    -----
    $259!!!! (At Music Workshop in Salem, NH)
    
    In summary, this seems like a highly featured, intelligently featured,
    well-thought stage mixer, also quite good for recording at a phenomenal
    price.
    
    Unfortunately, I have no information on its audio specs.
    
    Some comments on things that you or I think may be "missing" from
    the MX-8R
    
    1) EQ for each channel.  This thing has NO EQ features!!  

       So far as I know, this is a bit unusual (maybe it explains the
       low price).   It probably isn't much of an issue for using it
       as a stage keyboard mixer (as it was INTENDED to be used) but
       could be a problem using it to augment a porta-studio mixer
       (one of my intended uses) or other recording usages.
    
       You should understand here that I seem to be
       criticizing the machine for not doing "well" something it wasn't
       intended to do anyway.  So my "criticism" (as such) is entirely invalid,
       but I mention it because like most people with limited budgets I
       often need to have my horses to produce milk as well as drag the 
       plough.
    
    2) volume controls for the effects returns.  
    
    This is important mainly for recording (in my admittedly naive
    opinion).  Reasons:
    
    	o Some effects (especially triggered effects) have to have a
          certain input level to drive them or get good quality sound,
    	  thus you have a little less flexibility on how to set the
          send levels.  Since what you send also partially determines
          how much is sent back, it would be nice to be able to control
          the mix level of the return from the front panel of the mixer,
    	  rather than the back panel of the effect (which is where many
          effects have their output level pots if they have them at
          all.)   No big deal though.  Lots of decks don't have this.
    
        o Having a volume pot for the effects return sorta gives you
          "free extra channels".  These channels aren't as flexible
          as normal channels but often are all you need.
    
770.47Pre/Post effect controlDREGS::BLICKSTEINDaveTue May 19 1987 19:439
    re: .45
    
    On the pre/post feature: simply described, when it sorta determines
    whether the channel volume pot affects how much signal is sent to
    the effect (i.e. the effect level can be automatically adjusted
    WITH the channel signal level in the mix or it can be independent
    of the channel's volume in the mix).
    
    	db
770.48Toa TooDRUMS::FEHSKENSTue May 19 1987 20:537
    Toa also makes a similar rack mount unit.  I don't have details
    handy, but it is 4 channels, includes 4 midi thrus, and I believe
    it has eq.  Sorry, I don't remember its effects sends/returns stuff.
    2 rack spaces high.
    
    len.
    
770.49TOA D4REGENT::SIMONEThu May 21 1987 17:1747
    Re .48
    
    Its the TOA D4.  I have one and I like it very much.  It has two
    possible drawbacks, namely its only four channels wide and its not
    midi controllable.  The four channel problem can be solved by
    purchasing the DE (I think?) which is a 6 channel expander.  There
    is a bus link which connects the two, so that for all intents and
    purposes you have a 10 channel mixer.  This would be four rack spaces.
    
    The D4 and DE can be had for $300 apiece.  I got mine at LaSalle
    "on sale".
    
    Approximate D4 specs to the best of my recollection:
    
    4 Input Channels
      - RCA or 1/4" jacks on all channels.  XLR jack for mic. on channel 4.
      - 2 band (treble/bass) eq on all channels
      - RCA acc. send/acc. receive jack on each channel (for channel
        by channel outboard effects - I'm thinking of getting the Korg
        rackmount unit with 5 EQ's to give me independant EQ's for each
        channel on the D4)
      - Trim pot on each channel - amplifies prior to effects
      - Two Effect send (called EFF and AUX) controls per channel
      - Gain for each channel - amplifies after effects
      - Pan control for each channel
    
    o EFF send, AUX send controls
    o EFF return to stereo, AUX return to stereo controls
    o EFF return pan, AUX return pan to stereo
    o EFF return to SUM, AUX return to SUM (independant mono mix)
    o SUM input - extra input just to the mono mix
    
    o Left Volume, Right Volume, SUM (mono) volume controls
    o RCA acc. send, acc. recv jacks for L,R and SUM outputs for additional
      effects.
    o RCA and 1/4" jacks for all outputs and I believe for all returns
      also.
    o 1 input to 4 output midi thru circuit
    o Switched 120V AC jack

    More stuff I cannot remember.
    
    If you're not looking for midi control and need 4 or 10 channels,
    this is a great rackmount mixer, with the flexibility to be used
    in many different setups.
    
    Guido
770.50more TOA infoOASS::B_MCMILLANThu May 21 1987 17:3342
    TOA D-4 and D-4E
    
    o 4 input channels, expandable to 10
    o Rackmount mixing of electronic music and sound for live performance
      or studio recording applications
    o 1 x 8 MIDI-THRU function prevents data loss or delay
    o Provides stereo and mono mix
    o Each input has direct output
    o Five busses (stereo Left, Right, Eff, Aux, & Sum) for maximum
      flexibility
    o RCA jacks, 1/4" jacks, & accessory patches on stereo Left and
      Right busses
    o Input channel patch points selectable to pre- or post-EQ and fader
    o Independent Effects and Aux Return to stereo Left, Right, & Sum
    o LED clipping indicators for each channel, Left, Right, & Sum
    o Electronically-balanced XLR and unbalanced 1/4" connectors on
      Sum output
    o Headphone monitoring of stereo L&R, Sum, Eff, or Aux
    o LED indicators for MIDI-THRU and power-on
    o Circuit-breaker protected with automatic re-set button
    o 19" rackmount bracket included; removable for use outside of rack
    o Each channel:
    	Trim control			Post-effects send
    	LED peak indicator		Aux send, switchable to pre-
    	Level control			or post-EQ/fader
    	Pan control			1/4" phone and RCA jacks
    	2-band EQ
    o D-4's fourth input channel features electronically-balanced XLR
      mic connector with switchable 48-volt phantom power
    o D-4E's input channels 5-8 feature balanced XLR mic connectors
    
    
    
    Price:
    		D-4	$299
    		D-4E 	$329
    
    
    
    
    
    hope this helps.................Bruce
770.51simmons mixerGIBSON::DICKENSDistributed System ManglementThu May 21 1987 23:2613
    I think the simmons is around $1K.  It's an incredibly small box, just
    one single-height unit.  It has three band eq and two effects sends per
    channel, but no aux bus or tape input reassignment, i.e., not a good
    recording mixer.  It also has a variable fade rate that's settable *per
    channel*!. 
    
    Basically the way it works is that you can control just the levels of
    all eight channels, or you can control all the parameters of just one
    channel at a time.  Weird.  Supposedly you can even drive it live
    with your sequencer to do a crude automatic mixdown. 
    
    More in this (maybe last) month's Music Technology.
    
770.52COMPRESSION: The Mystery EffectSALSA::MOELLERTue Aug 04 1987 20:4024
    Recently I was adding a (ahem) sampled string bass line to a friend's
    recording, and, as we listened to a rough multitrack > stereo mix,
    found that the bass line tended to disappear in the mix.
    
    Having more time than sense, we decided to try using some compression
    on the bass signal, and tried it as a mixdown effect. What happened 
    was that the velocity-sensitive bass line lost all dynamics, and
    gained quite a bit of (unwelcome) sustain. Guitarists take note.
    
    So we rewound the tape, backed off the 'threshhold' control, and
    cut a bit of bottom ~50 hz using a parametric EQ. This time the
    bass could be louder, as the boom at the bottom was gone (using
    these speakers; your mileage may vary) and there was now some
    dynamics in the track.
    
    So, silly me ! What is it that a compressor does ? I've had this
    in my Ibanez Multieffects unit for years and only used it to add
    some sustain to piano lead lines. I've never used it for percussion
    sounds. It DOES boost background noise. Is the dynamic range all
    it 'compresses' ? I've noticed that some settings will cause a smooth
    bass sound to suddenly get a 'pop' transient, like thumb-popping
    an electric bass.
    
    karl moeller tucson az usa    
770.53To compensate for cheap mics???DREGS::BLICKSTEINDaveTue Aug 04 1987 21:4011
    I don't yet have a compressor (all the low end units I've tried
    are much too noisey as far as I'm concerned), but if I did, I'd 
    probably use it every time I used a mic, especially on vocals.
    
    Whenever I record with a mic, occasional notes, words, etc. 
    always seem to get lost.  The impression that I get is that mics
    do not have uniform dynamic response (i.e. a 1db increase in the
    source does not always cause a 1db increase in the mic at all
    levels).  A compressor could be a great help when this is a problem.
    
    	db
770.54guitars, keyboards, mics, salarysBARNUM::RHODESWed Aug 05 1987 01:3229
Think of a compressor as a dynamic volume control that adjusts to keep the
input signal below a certain threshold of volume no matter what.  When the
input signal is very high, the compressor cuts the signal "volume" to
the threshold level.  As a signal tapers off (ie. sustained piano ringout),
but is still above the threshold, the compresser gradually turns the volume up 
to hold the output level at the constant threshold.  Only when the signal 
finally falls below the threshold, does it decrease in volume over time.

Compressors are used on mics as level controls (don't want a transient to
pin that VU meter, do we?  Set the threshold to 0 db!).  They are generally
used on guitars for sustain effects.  In this case you set
the gain to be very high, but set the threshold to be very low.  When you
pluck a string, your input signal tries to exceed the threshold by many
db, and thus compression occurs.  The output volume eventually dies out 
(usually after many seconds), when the vibrating string's dynamic input
level finally falls below the threshold.  Until then, however, the output 
volume remains constant and thus yields constant sustain.  An added compressor/
guitar trick is to patch a distortion box just after the compressor in the
chain so that the (constant) sustained signal coming from the compressor
drives the distortion box to create constant volumed (or sustained) distortion.

Cheap compressors can't react quickly to an input transient and thus
a signal larger than the threshold can squeek through for a short time until 
the compressor catches up and squashes the signal volume down to the 
threshold level.  This characteristic will cause an audiable "thock" or 
some such quick transient generated sound.

Todd.

770.55Is this True?STAR::MALIKKarl MalikWed Aug 05 1987 15:4212
    
    	I've heard that compressors also change the timbre of the signal.
    I assume that this is the result of boosting not just 'notes' but
    the individual harmonics of a note.
    
    	With a piano, for example, the harmonics decay at different
    rates - the compressor will dutifully try to keep things constant.
    
    	I've also heard that vocalists like it for this very reason
    - by boosting certain frequencies, it 'fattens' up the sound.
    
    					- Karl
770.56I don't know about changing timbre, butMPGS::DEHAHNWed Aug 05 1987 17:4922
    
    Re: fattening
    
    Well, it really oesn't boost frequencies per se, but you can drive
    the VCA hard, which will produce warm harmonics that tend to fatten
    the sound. I have a thin voice, so it works well for me.
    
    A lot of compressors come with a noise gate built in. If you set
    the gate up correctly, you can control the amount of sustain on
    your piano. You have to be careful to get the decay right so it
    doesn't sound choppy.
    
    Compressors working at a ratio > 8:1 are functioning as limiters,
    which set a hard ceiling on how strong a signal is passed. This
    is extremely useful for live sound systems used for rock music.
    Drivers are expensive, and blowing the whole stack kills the show.
    A limiter set to a bit below the clip point of the amps (and the
    power rating of the drivers) will keep things out of the danger
    zone.
    
    CdH
    
770.57THE780::FARLEESo many NOTES, so little time...Wed Aug 05 1987 21:1224
    re: .54,
>    Cheap compressors can't react quickly to an input transient and thus
>a signal larger than the threshold can squeek through for a short time until 
>the compressor catches up and squashes the signal volume down to the 
>threshold level.  This characteristic will cause an audiable "thock" or 
>some such quick transient generated sound.

    Some bass players use this characteristic to get a sharper attack
    and a bit more percussiveness. It produces an envelope like:
    |\
    | \
    |  \_________
    |            \________________
    |                             \_____________
    |                                           \____________
    
    rather than
    
    
      ________________
     /                \_______________
    /                                 \_________
    |                                           \_______
    |                                                   \_____
770.58TIMBER!!!!!!!BARNUM::RHODESThu Aug 06 1987 12:398
RE: Timbre changes

This is true.  Upon plucking an acoustic guitar string, the timbre changes 
slowly over time - as does the volume - as the note rings out.  Add compression
and only the timbre changes over time while the volume remains constant.

Todd.

770.59NO TIMBRE CHANGE JON::ROSSum....and twelve tones all in a row...Thu Aug 06 1987 14:0416
    
    EEK! No. Gotta disagree. Unless you're overdriving the unit,
    there is no timbre change. The system is linear in the sense
    that the compressor acts on the amplitude of the components
    of the composite waveform (input) equally: a low freq. sine
    component is boosted as much as a hi freq sine component. 
    
    There is no modification of any single, or group of, sine
    components to the wave being compressed. The wave out is the
    wave in with only its amplitude changed: NO TIMBRE CHANGE. Sorry.
    
    Well, one compressor DOES do frequency selective modification...DOLBY. 

    But thats not what were talkin.
    
    
770.60where's EDD when you need it?TIGER::JANZENTom LMO2/O23 2965421Thu Aug 06 1987 14:3717
I like to use an automatic gain control, which is not compressor,
on piano.  I hit a soft chord, then, while holding the chord,
a loud staccato note, then wait for the AGC (cheap sustain, just like the
AGC in a little tape recorder) to bring up the soft chord.
It's one way to get a crescendo out of a piano.
  ______________________                            __________________
_/                      \          ________________/
                         \________/

 |
O  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
pp                       |
                        O  
                     ff >
                        .
T-o-m
a compressor does not turn up the low levels, it squishes the high levels.
770.61SALSA::MOELLERThu Aug 06 1987 15:4625
    Hiya Tom! long time no spar ! I like your scheme for getting
    a crescendo out of a piano.. uh, how does one find an automatic
    gain control OUTSIDE of a tape recorder ? 
    
    I do disagree with one point, though.
>a compressor does not turn up the low levels, it squishes the high levels.
    I believe that it does both.. When the input signal is low, there's 
    lots of background noise, as the compressor is trying valiantly to 
    maintain the desired output level.. when the input is high, it does
    indeed 'squish'/ compress the signal.
    
    And for a couple of notes back, yes, the waveforms you drew (someday
    we'll all have color graphics) do indeed describe what happens to
    a bass signal.. the rise time is quicker, and then it's damped,
    causing a spike/thwock where none was before. This is a result of
    the compressor 'attack' setting.. vs. 'threshhold', which affects
    the amount of lowlevel rise/highlevel squish over the life of a note. 
    
    Regarding the 'volume vs. Timbre' debate.. timbre is perceived as
    frequency and volume variations over time.. so I guess I would say
    that the compressor does affect timbre as the note sustains.

    good, high level input, y'all.
    
    karl
770.62welcome back Mr. JanzenMPGS::DEHAHNFri Aug 07 1987 14:0119
    
    Tom is right, compressors do not raise the volume, they only "squish"
    the top of the signal. This decreases the dynamic range of the signal
    thus bringing the lower levels "closer" to the peaks. When the input
    level is low, like under the threshold of the compressor, it is
    effectively out of the circuit and contributes little to the signal.
    Of course, in the real world they do have some small effect.
    
    Noise gates do the opposite. They expand the signal downward under
    low level conditions, which increases the effective dynamic range
    and pushes the noise floor down to the level of the compressor's
    noise floor. Great for musicians who use lotsaeffects.
    
    CdH
    
    
    
    
    
770.63Your results may vary (but I doubt it).ACORN::BAILEYSteph BaileyFri Aug 07 1987 22:2042
    My noise gate doesn't do that.  I would like to see one which does,
    but I think it is theortically impossible to pull a signal out of
    the noise unless you do something like make assumptions about the
    harmonic content of the noise (can you say DOLBY).
    
    All my gate does is move the input signal to the output until the input
    drops below the threshold.  Good for my DX7 which puts out the worst
    thermal hiss that I have ever heard.  I am soon going to get in
    there an redesign the output stage myself, I am so tired of listening
    to it.  Anyway, noise gates produce the gated-snare effect.  That
    is, a snapping decay.  I guess I should make some amplitude envelope
    drawings here:
    
                   ----
                  -    --
                 -       --
                -          --
               -             --
              -                --
       -------                   ------------- Signal input
                  ----          
                 -     --
                -        --
     ++++++++++|+++++++++++--++++++++++++++++++++++++++threshold
                             |
               |             |
       ---------             ----------------- Signal output
      
    The beginning of the attack and the end of the release are made
    more percussive because the output is off until they reach the
    threshold.
    
    As far as compressors go--strictly speaking, a compressor amplifies the
    quiet sections, and attenuates the loud ones (as Mr. Moeller has
    experienced).  That is, it compresses all the sound into a small
    dynamic range, which may be centered at an abitrary point. A device
    that just attenuates the loud stuff is a limiter. That is a formal
    definition, and what they units actually do is not always related to
    what they are called. 
    
    Steph 
                         
770.64About Limiter-Compressors...HSTSSC::LEHTINENTimo Lehtinen, TSSC HelsinkiSun Aug 09 1987 15:3540
    RE: -2 - n 
    
    I think the confusion here about compressors might come from
    the fact that most studio devices are called Limiter-Compressors
    (or vice versa). Still it means the same thing as "Compressor"
    in that it is capable of raising the volume when the input level 
    is low and reducing it when the input level is high. 
    
    A limiter-compressor is called that because it can be set to act
    ONLY as a limiter if required. This is the most common usage
    of this kind of device and is achieved by setting the Threshold
    high and Compression ratio to infinity or near it. Now whenever
    the input level gets over the threshold level the device starts to
    do it's "stuff" and since we've set a ratio of infinity it performs
    heavy limiting. 
    
    If the threshold is set low a device of this kind also tries to
    increase the volume of low input to do reduction of the dynamic 
    range. Higher threshold settings are often preferred because 
    that way the compressor sounds more "transparent". In other
    words you can't hear it working since it doesn't get hold of
    the quieter notes and most importantly of hiss. I believe
    a compressor without a threshold adjustment is never called
    limiter-compressor. I.e. all the "stomp-boxes" are plain
    compressors.
    
    Since limiter-compressors' fastest attact times typically are 
    something like 5 - 15 ms they are not suitable for limiting
    fast transients (peaks) in prevention of overloading say
    a digital recorder. Something called Peak Limiting is used
    on these kind of applications. The difference is in the way the 
    limiter works. It uses more like brute force or controlled
    clipping (distortion with softer edges) if you like, to prevent
    any high peaks from getting through no matter how fast transients
    might be involved. 
    
    This is how I've understood it. Any comments or critizism wellcome.
    
    Timo
    
770.65MTBLUE::BOTTOM_DAVIDFat man in the tub w/da bluzWed Dec 30 1987 10:5535
    I received my Symetrics 525 last night. So I jumped right in and
    began using it to see what it will do. Hmmm I like it.
    
    The 525 is a stereo compressor/limiter/expander/gate. It features
    the ability to operate in stereo mode or dual independant. Front
    panel controls are simple (in theory anyway) there is a exp/gate
    threshold, comp/limit threshold, ratio, and output level. The exp/gate
    control has a nice led to tell you when the gate is on, the comp/limit
    threshold has one to tell you when the limiter is on. The output
    has a group of leds to tell you where the limit is set tom,, this
    moves up and down with the dynamics of the music. Back panel features
    in/out and control loop. The control loop can be used to make the
    limiting feature frequency sensitive, probably the most practical
    use would be as a d-esser by using an eq in the loop, I didn't try
    this yet.....
    
    I found the compressor to be very good, when adjusted properly it
    is unnoticable and very smooth. It makes a great guitar compressor
    too....
    
    Specs are very good. There seems to be no colorization of the sound
    coming out of it.
    
    The unit comes with a good instruction book, it has some sample
    set ups, schematics etc. One thing that I liked even though it was
    only a 14 cent issue, they supply the stamp for the warantee card...
    first time I've seen that before...
    
    List is $499, you can do much better by shopping around. Due to
    an error on the part of East Coast Sound I got a real steal on this,
    they've asked me not to quote y'all a price...essentially I got
    it for a couple of bucks over dealer cost...probably the deal of
    my life...
                                                                    
    dbII
770.66DBX 903 compressor/limiters?OILCAN::DIORIOWed Jan 06 1988 13:455
    Does anybody know anything about DBX 903 compressor/limiters?
    Are they any good? Features? Rackmountable? Price? 
    
    Mike D.
    
770.67ART MULTIVERBOILCAN::DIORIOWed May 11 1988 15:2624
    I just read an ad in Electronic Musician.
    
    ART MULTIVERB
    
    Up to 4 incredible studio sounds simultaneously.
    * Reverberation * Pitch Transposition *Digital Delays
    * Arpeggiated Effects * Pitch Shift Doubling * Chorusing
    * Reverse Gates * Imaged Doubling * EQ
    
    * Easy to use front panel controls
    * 200 user memory locations
    * Over 100 studio-crafted presets
    * Fully programmable
    * Full parameter control
    * Random access keypad
    * Ultra-wide bandwidth
    * Full midi with battery backup
    * Remote footswitch jack with preset increment
    * 32 character LCD
    
    No price of course. Sounds good. Sounds expensive.
    
    Mike D
    
770.68But it did sound nice to the reviewer...JAWS::COTEBohm &amp; Jacopini never led Cub Scouts...Wed May 11 1988 15:347
    I read a review of this unit somewhere and it seems the operative
    phrase was "up to" 4 effects...
    
    I don't remember it as being gawd-awful expensive (<$1K). Subjective
    call there...
    
    Edd
770.69f.fo.for.fore.fores.foresh.foresh.foreshadow....SRFSUP::MORRISI don't drink, so I bought a GPZThu May 12 1988 05:4110
    re: .67
    
    see 1344.8, .10, .11
    
    You heard it here first......in COMMUSIC!!!!!
    
    Ashley
    
    P.S. Why is it that we usually know more about products than salesmen,
    and we know it first???.....and we don't make commissions???...and....
770.70I hate noise!DREGS::BLICKSTEINThe height of MIDIocrityThu May 12 1988 12:4616
    Anyone have any experience with the DOD 7nn compressor series?
    
    They have a compressor with a De-esser for around $200 in a rack mount
    (of course).
    
    I know there are probably some DOD pedal users out there, but I've
    always associated DOD with junk.  Their main business seems to be those
    noisey stomp boxes that guitarists eat up.  Almost every compressor
    around $200 I've tried out has been far too noisey (including the
    ART, the Yammy GC2020).  I've been thinking about getting a Symetrix
    but the prospect of having a De-esser has intrigued me enough to look
    into this DOD unit.
    
    Anyone tried one?
    
    	db
770.71my thoughtsTWIN4::DEHAHNThu May 12 1988 12:5926
    
    DOD stuff, in general, is basic bang-for-the-buck material. I've
    repaired a lot of DOD products, and I'm not too impressed with the
    quality of construction, electronics, or components. They use real
    cheap connectors, for example.  However, if you're on a limited
    budget, they will get the job done. I have no experience with the
    DOD compressor.
    
    However, the Symetrix is a studio quality unit, in a whole different
    league. A fantastic piece of gear. Also, check out the new Rane
    DC24. That's what's going to replace my Symetrix 525. A unique feature
    of the DC24 is a built in crossover, so you can compress/limit/gate
    the two channels in two frequency ranges. For example, in a sound
    reinforcement application, you can limit the high end at a large
    ratio to protect your compression drivers, yet compress the bottom
    end a little less radically to preserve the punchy sound.
    
    Does the DOD let you compress AND de-ess at the same time? Most
    unit's will let you do only one at a time. If you are after an
    inexpensive solution to do both at once, then consider a dbx 163x
    compressor and 263x de-esser together, in one rack space, for about
    $200 or so.
    
    CdH
    
    
770.72DUD on DODDREGS::BLICKSTEINThe height of MIDIocrityThu May 12 1988 17:2815
    Is that to say that both dbx units can be had for $200 or that EACH
    dbx unit is $200?
    
    I don't know if the DOD unit will compress and De-ess at the same time. 
    It hadn't even occurred to me that it might not.  Anyway, what you have
    said tends to confirm my own observations about DOD and I'm inclined
    to (continue) avoiding their stuff, although I think I'm gonna try
    this DOD compressor out as a matter of curiousity.
    
    If you're "replacing" your Symetrix 525, does that mean your gonna sell
    it?  If you are, let me know.
    
    Thanks for the help, advice, etc.
    
    	db
770.73I hope I didn't upset anyoneTWIN4::DEHAHNThu May 12 1988 17:5429
    
    In order to avoid any confrontations from DOD fans, I should have
    given a disclaimer.
    
    Any opinions expressed on DOD products by this noter are of his
    alone, and are based on his own experience. They do not mean to
    discredit their products, only to offer an opinion.
    
    Re: compresion and de-essing
    
    They are essentially the same thing, the difference is de-essing
    is compression through a bandpass filter. You can de-ess with any
    compressor that has side-chain inputs, using an external equalizer.
    However, most compressors that offer de-essing capability that I
    have seen switch in a built-in eq, that creates the bandpass. Thus,
    any information outside of the passband is not effected by the
    compression. Which means that it does one thing or the other across
    the whole spectrum.
    
    The dbx units are designed for musicians. They have very little
    controls, and you're stuck with soft compression at a fixed ratio.
    For the money, though, they will do the job and are well made and
    quiet. I've seen them for as low as $99 each mailorder, hence the
    $2300 price for two. I think the rackmount adaptors are standard.
    They are one rack space high and a half rack width each.
    
    CdH
    
    
770.74DOD is OK by me.CTHULU::YERAZUNISThe light that burns twice as bright burns half as longThu May 12 1988 18:196
    I have the DOD Digitech 2000 2-sec digital delay stomp-box.  Works
    fine, nice and quiet, punt-proof.
    
    Based on _my_ experience, I would buy DOD again.
    	
    	-Bill Yerazunis 
770.75was someone bashing digitech?TIGER::JANZENTom LMO2/O23 296-5421Thu May 12 1988 19:059
    My dod digitech rds1900 works OK except I broke a pot once somehow
    so it was hard to find a replacement in the mouser catalog but I
    did.
    My impression is from ads that digitech is more professional now
    than when it built the 1900.  It revamped its whole line
    a year or so ago, using CAD.
    I just don't plan buying any musical equipment, since I gave up
    music.
    Tom
770.76Same company, different product linesCSC32::G_HOUSEGreg House - CSC/CSThu May 12 1988 20:109
    Isn't the Digitech stuff supposed to be a higher quality line than
    the DOD?  I've had a RDS3600 digital delay for about 3 years now
    and it's impressed me.  Admittedly, that doesn't take too much,
    as I'm not used to high end gear.  It's dead silent compared to
    my Ibanez "Analog Delay and Multi-Flanger" (verrrrry noisy) and
    MXR Phase-100 (shoosh-shoosh).
    
    Just a guitar hack anyway...
    Greg
770.77All my songs have 3 chords, anyhooSRFSUP::MORRISI don't drink, so I bought a GPZThu May 12 1988 21:479
    Maybe instead of the compressor/de-esser route, you might want to
    consider a rocktron Hush.   Very hi quality stuff.
    
    And I like my Digitech 2 second stomp box delay/sampler (I use the
    word loosely).  Slightly less praise for my DOD stomp box compressor
    and noise gate.  Great Phaser and Flanger (one of the old ones,
    with a 110V cord included!).  Trashy Chorus.
    
    Ashley
770.78Hu(s)h?DREGS::BLICKSTEINThe height of MIDIocrityFri May 13 1988 13:3812
    I don't understand.  A hush is a completely different thing than a
    compressor or a de-esser.  Perhaps your thinking of a gate, which
    is somewhat like the Rocktron Hush.
    
    Sounds like stuff with the Digitech label is ok, but I have yet to
    try out a DOD, Boss or just about any other of those stomp boxes
    that *I* didn't think was VERY noisey.  I've pulled all that stuff
    out of my rig.
    
    BTW. do the symetrix or the dbx have gating?  Limiting?
    
    	db
770.79questionsOILCAN::DIORIOFri May 13 1988 17:209
    HAs anyone heard anything good or bad about Alesis' Micro Limiter?
    
    I've heard that it is really not a compressor, but strictly a limiter
    and uses a hard knee.
    
    How about the half rack space unit from Roland? Is it noisy. Anybody
    tried one out?
    
    Mike D
770.80MTBLUE::BOTTOM_DAVIDComing soon on a node near youFri May 13 1988 17:214
    Yes the symetrix has gating. It's a very nice unit, I bought one
    last fall.
    
    dave 
770.81TWIN4::DEHAHNFri May 13 1988 17:5610
    
    The dbx compressor, 163x, has no gating. Not unusual for a unit
    that cheap. The gate is the 463x, I believe.
    
    The symetrix 525 changes its action from soft compression to hard
    knee limiting by varying the ratio control. 
    
    CdH
    
    
770.82They all seem to be lacking stuffTYFYS::MOLLERVegetation: A way of lifeFri May 13 1988 18:1723
    As far as compressors, Limiters and Reverbs go, they screw up my
    dynamics way too much (I play guitar, and am known to play with
    more than a consistant presure - I suppose thats equal to velocity
    on a keyboard). I've found that I have to use a mixer that basically
    takes the input, splits it into 2 signals, one going into the effect,
    the other being mixed with the output of the effect. This takes
    care of the peculiar added equalization, and some of the dynamics
    issues. I even do this with my PAIA limiter, since it sometimes
    forgets to quit limiting & truly destroys the dynamics of what I'm
    doing. Compressors (I'm talking about the stomp box variety) are
    handy for sustain, but until I started using a mix around technique,
    I didn't use them much.
    
    	                    /-->-----[volume pot]->-----\
                           /                             \
    	Input Signal ---->(                            [Mixer]----> Output
    			   \                             /
                            \--[Effect]->-[volume pot]--/
                                
    You have to make sure that the effect doesn't swap the output 180
    degrees (this is corrected where necessary by a few op-amps)
    
    							Jens
770.83exSRFSUP::MORRISI don't drink, so I bought a GPZSat May 14 1988 00:344
    re: hush.
    
    I don't know, but I think that the Hush has de-essing circuitry
    as part of the gate.
770.84I think the hush is intended for a different applicationDREGS::BLICKSTEINThe height of MIDIocrityMon May 16 1988 12:593
    The Hush ads strongly imply that it's for use with line instruments like
    guitar and keyboards.  If so, a de-essing circuit would be undesired
    messing with the EQ.
770.85TWIN4::DEHAHNMon May 16 1988 20:306
    
    Best I know the Hush is a noise gate, not a compressor. Two similar
    devices that work the opposite way.
    
    CdH
    
770.86PAULJ::HARRIMANLet's keep sax and violins on TVTue May 17 1988 03:528
    
    re: Alesis Micro limiter
    
      Yeah, it's neat. 125 bucks max for a quiet little hardknee limiter.
    Great for miking mike-eaters, etc. You can fit three in a rack space.
    I have been thinking about picking one up...
    
    /pjh
770.87GIBSON::DICKENSSurfing with my BuickWed May 25 1988 17:5613
    The hush is not just a straight noise gate.  From what I can tell it's
    a set of two or more gates, each acting in parallel on a different
    frequency band. 
    
    So the effect is that when you're playing only lower-register notes, it
    damps down the the high frequencies hard, knocking out the hiss
    completely.  Then when you hit a high note it opens instantly. 
    I like it.  When you're playing heavily overdriven guitar it is
    truly the best thing since sliced bread.  It even tends to remove
    fretting noise if it's turned up high.
    
    						-Jeff
     
770.88Can a guitar play percussion?IOENG::JWILLIAMSZeitgeist ZoologyFri May 27 1988 17:023
    But, but, but . . . I *LIKE* fretting noise!
    
    						John.
770.89Private joke - explained at release of Commusic VDREGS::BLICKSTEINThe height of MIDIocrityFri May 27 1988 18:075
>   But, but, but . . . I *LIKE* fretting noise!
    
    See Karl????
    
    	db
770.90Alesis compressor?NRPUR::DEATONtired of thinking up cute quotesMon Mar 20 1989 20:1817
RE < Note 770.86 by PAULJ::HARRIMAN "Let's keep sax and violins on TV" >
    
>    re: Alesis Micro limiter
>    
>      Yeah, it's neat. 125 bucks max for a quiet little hardknee limiter.
>    Great for miking mike-eaters, etc. You can fit three in a rack space.
>    I have been thinking about picking one up...
>    
>    /pjh

	Paul,

	Did you ever pick up one of these units?  If so, how well does it 
perform?  Anyone else get one of these?  Opinions solicited.

	Dan

770.91wal, i got a different dealTALK::HARRIMAN1000 Pints of LiteTue Mar 21 1989 14:108
    
    re: .-1
    
    As it happened, I picked up a Biamp quad limiter for $100 and four
    channels of dbx for about $300 a while back. But I tried the Alesis,
    and my original opinion is unchanged.
    
    /pjh
770.92How much of a test did you put it through?NRPUR::DEATONtired of thinking up cute quotesTue Mar 21 1989 14:509
RE < Note 770.91 by TALK::HARRIMAN "1000 Pints of Lite" >

	The reason I had asked was because I heard here and there that it had
a tendancy to pass distortion (now THAT's an interesting way to phrase it, if I
do say so myself &^).  The scuttlebutt was that it might be o.k. for ammatuer
studios, but wouldn't stand up for live use or quality studios.  Any comments?

	Dan

770.93TALK::HARRIMANRoget's BrontosaurusWed Mar 22 1989 13:1111
    
    
    Welllll, my dbx will "pass distortion" through too, if it's further up
    the audio chain.
    
    I dunno. Sounds fishy to me. I have a lot of "pro" gear, and I think
    that the Alesis, although not as pricey as a fischer-technik or
    something like that, still performs well enough for anyone who is
    perusing this conference. Personal opinion, of course.
    
    /pjh
770.94Pass signal?NRPUR::DEATONtired of thinking up cute quotesWed Mar 22 1989 13:2312
RE < Note 770.93 by TALK::HARRIMAN "Roget's Brontosaurus" >

	Actually what I meant by 'pass distortion' was not that it would allow
distortion to pass through unhindered, but rather, as the biological counterpart
suggests, pass signal with something undesirable added.  In this case, 
distortion.  Perhaps I chose the wrong phrase or analogy?

	Whatever the case, it sounds like you did put it to that test and were 
reasonably satisfied.

	Dan

770.95cmprssr nded mybe?WEFXEM::COTECall *who* Ishmael???Tue Dec 26 1989 18:4517
    I think I need a compressor...
    
    I'm increasingly unhappy with the quality of my tapes produced direct
    to stereo cassette from my board. Much of the troubles seem to stem
    from my drums. The cymbals seem to saturate the tape at any level high
    enough to retain any 'sizzle'. Sure, I can back off the level, but then
    they get lost...
    
    Seems to me a compressor would help, no?
    
    Stupid question: Um, where do I put the compressor? (In the circuit,
    not in the room!) Since compressing the entire mix seems to be what I
    want to do, inserting it right before the deck might work, no? But
    then, without a 3-head deck I can't monitor the taped signal. Maybe on
    a buss?? Help?
    
    Edd
770.96behind the couchSWAV1::STEWARTThere is no dark side of the moon...Tue Dec 26 1989 19:3914


>    Stupid question: Um, where do I put the compressor? (In the circuit,
>    not in the room!) 

	Put it on the line outs of your drum machine if you're happy with
	everything else.  You might consider dBx signal processing for your
	cassette deck, also; it increases the effective dynamic range of
	your deck by 10-20 dB.  Wish I had it.




770.97MIZZOU::SHERMANECADSR::SHERMAN 235-8176, 223-3326Tue Dec 26 1989 20:0411
As I recall, the best place to put a compressor is right before the tape.
Otherwise, you risk pegging the meter.  Also, monitor the amount of compression
and try to weed out hot spots.  The recordings I was most satisfied with had
just a tad of compression going on most of the time.  You don't want to kill
your dynamics.  And, you don't want the compression to make things unnatural.
I figure that, as a rule, if you do compression right you won't notice it in
the final mix.  Also, I only diddled with compression during mixdown.  When
I was not going to tape I tended to avoid compression so that I could enjoy
wider dynamic range.

Steve
770.98What about a limiter?MRSVAX::MISKINISTue Dec 26 1989 20:083
    Wouldn't a limiter work Edd?
    
    _John_
770.99dbx instead of compressionTALLIS::PALMERColonel ModeWed Dec 27 1989 12:156
    dbx NR is fantastic. You get 2:1 compression on the tape, allowing much
    more dynamic performances. Why mangle your music when for the same
    price you can have it all? It has the added advantage of being dead
    quiet compared to Dolby B or C.
    
    Chris
770.100Get a limiterDREGS::BLICKSTEINConliberativeTue Jan 02 1990 14:5120
    re: .98
    
    That's just what I was going to suggest.  You might find something
    like the Alesis Micro series limiter to do THIS particular trick.
    
    However a good full-fledged compressor/limiter is always good to
    have around if you find yourself doing much in the way of recording
    live tracks off mics.
    
    BTW, in case anyone doesn't know.  "Limiting" is one application
    of compressing.   Most compressors allow you to adjust the compression
    ratio (like an increase of 4 db should be cut back to 2 db would
    be a 2:1 compression ratio).
    
    "Limiting" is essentially just compression with an infinity:1 ratio.
    
    That is it puts a "ceiling" on the dynamic level.  Anything above
    a certain threshold is cut back to the threshold.
    
    	db
770.101STROKR::DEHAHNTue Jan 02 1990 19:027
    
    Limiting is usually delineated by being hard knee compression of over
    8:1 ratio. Not exactly nice sounding, but effective. Edd, you really
    want a compressor.
    
    CdH
    
770.102opinions on DBX 163X?ZYDECO::MCABEELearning the First Noble TruthWed Jun 27 1990 18:178
I'm interested in a compressor for recording vocals, guitar, mandolin, fiddle
and various flutes.  Some friends (with limited experience) have recommended
the DBX 163X, which is cheap but doesn't seem to have many controls.  Is this 
a reasonable unit, or do I really need more control over the parameters?

Is there anything else under $200 that would do the job better?

Bob
770.103Threshold, Compression, and Rate Parameters are All There AreDRUMS::FEHSKENSlen, EMA, LKG2-2/W10, DTN 226-7556Thu Jun 28 1990 14:229
    Most modern compressors don't have a lot of controls, and most in fact
    have an "automatic" mode where all you need to adjust is the
    compression factor.
    
    There are probably compressors that are "better" than the dbx, but not
    for less than $200, and probably not a whole lot better anyway.
    
    len.
    
770.104MIZZOU::SHERMANECADSR::SHERMAN 235-8176, 223-3326Thu Jun 28 1990 15:1611
    A friend of mine has an amp with "compressors" on it.  I was confused
    by the markings on two "volume" controls.  At zero volume, it has
    the symbol for infinity above an RMS number.  As the knob goes to high
    volume, the upper number (looked like dB, but they chose different
    units) decreases and the lower RMS number goes up or down (don't
    remember which).  This is from memory, so I might not have this right.  
    My guess is that the upper indicates how much compression (sort of in
    dB) will be done.  The lower number indicates at what value RMS the output 
    will start to be compressed.  Is this standard?  Anyone care to elaborate?
    
    Steve
770.105QUIVER::PICKETTDavid - $ cat &gt; | ccThu Jun 28 1990 17:3012
    I was asking the same question a while back, and the upshot of the
    whole thing was: you get what you pay for.
    
    Some people indicated that the dbx163x did a decent job, but robbed you
    of complete control for those exception conditions that spring up now
    and again.
    
    I'm still considering a compressor, and am leaning toward the Audio
    Logic MT66 for $240. If you choose the 163, don't pay more than $110.
    I've seen it for as low as $99.
    
    dp
770.106ZYDECO::MCABEELearning the First Noble TruthThu Jun 28 1990 21:207
I expect to be ocassionally compressing two mic inputs simultaneously
so I was considering buying two 163X's, but it sounds like, for the same 
money, the MT66 would offer two channels and more features.  

Thanks for the input.

Bob
770.107STROKR::DEHAHNFri Jun 29 1990 13:0419
    
    Re: Steve
    
    If the 'compressor' is in an amplifier, it's most likely NOT a
    compressor, but a limiter. It's function is to clip off the input
    signal before it can drive the amp's outputs to clipping. In theory,
    that will sound better than the amp clipping, which is not always the
    case, but that's another rathole.
    
    The control is a threshold control, which sets the level when the
    limiter kicks in. It is usually expressed in terms of dB's below
    full power (0 dB) that you want to limit. Whether this knob turns CW or
    CCW is irrelevant. The infinity symbol is full limit, and the 0dB is no
    limiting at all. In between would be various steps of gain reduction.
    
    Peavey? Carver?
    
    CdH
    
770.108MIZZOU::SHERMANECADSR::SHERMAN 235-8176, 223-3326Fri Jun 29 1990 15:374
    Yup.  I told 'im that this looked to me like a limiter but it does say
    compressor on it.  I think it was a Peavey.
    
    Steve
770.109One person's quest for compressionFULCRM::PICKETTDavid - Will someone in Mass. please vote Republican for me?Fri Oct 26 1990 14:0024
    It's been a while since this note has seen activity, I thought I add a
    little more information.
    
    I recently got a Yamaha GC2020BII stereo comp/lim, and am very happy
    with it. It ran me $295 at Rhythm City. A nice add on feature is the
    noise gate. Yamaha calls this an expansion gate. The gate operates
    independently of the compressor, and is really handy if all of your
    synths generate aliasing noise like mine do. ;^) Nit: you can only
    adjust the threshold of the noise gate, you can't adjust attack/release
    like on the comp. I would have set the release a little quicker. The
    gate don't close quite fast enough.
    
    The Audio logic MT-66 was its nearest competitor. Sam Ash had the best
    deal @ $239 + shipping. After careful consideration, the Yahama was
    clearly worth the extra $50 bucks for specs, let alone the noise gate.
    
    I got a two channel compressor, not because I wanted to play DJ, and do
    annoying voice overs, but because I frequently record two souces of
    audio that have different compression need. If you are a student of
    Len-Monoism which teaches "Don't pay for stereo lest thou truly requirest
    it", you could get Len's celebrated Symmetrix 501 for the happy medium
    of around $260.  The 501 is single channel, but has superior specs. 
    
    dp
770.110DREGS::BLICKSTEINUnix: Familiarity breeds contemptFri Oct 26 1990 14:3725
    I also have a GC2020BII.
    
    I don't use the stereo for "ducking", but I found that it was just
    much cheaper than getting two mono compressors.
    
    I also use the compressor on mixdowns.  The "link" feature makes
    that much more useable - you couldn't do that with two separate
    compressors.
    
    For those of you not familiar with the GC, the "link" features causes
    each side to receive the same amount of compression.
    
    The GC is basically a nice piece - fairly inexpensive and HQ.  I tried
    a few other duals: a DOD, an ART, a GC2020A (earlier model) a few
    others; but I found that every other unit priced either in the
    GC2020BII's range or below it was considerably more noisey.
    
    And I regard noise to be one of the most obvious measure of a
    compressors quality.
    
    With the GC2020BII, I find that if I can adjust my other levels such
    that the compressors input and output adjustments are at unity gain,
    it introduces NO audible noise.
    
    	db
770.111KEYS::MOELLERSilopsism's not for everyoneFri Oct 26 1990 16:0711
    re fun with noise gates :  I'm a Tangerine Dream fan, and they
    regularly used an effect that I tell myself could only be done with a
    noise gate.  
    
    They'll have a timbre that sounds like a sustained synth pad, playing
    full chords, but it has a rhythmicality (is that a word?) that I think
    was done playing another, rhythm-only signal into the noise gate,
    which was set to 'open' the sustained pad only when a hit on the rhythm
    signal was received.
    
    karl
770.112Explain?WEFXEM::COTELight, sweet, crude...Fri Oct 26 1990 16:398
    re: linking
    
    Why is this good? I'm considering buying dual mono compressors
    precisely to avoid what you seem to like. 
    
    Why would I want to compress the left if the peak is on the right?
    
    Edd
770.113AQUA::ROSTNeil Young and Jaco in Zydeco HellFri Oct 26 1990 18:0010
    Re: linking
    
    If you're doing compression/limiting on a stereo signal (like in a
    mixdown) and want to keep the stereo image stable, you want equal
    compression on each channel.  Otherwise, the gain reduction being
    different for each channel causes things to "wander about" in the
    field.
    
    							Brian
    						  
770.114errata34903::EATONDFri Oct 26 1990 18:2811
RE <<< Note 770.109 by FULCRM::PICKETT "David - Will someone in Mass. please vote Republican for me?" >>>

>    The Audio logic MT-66 was its nearest competitor. Sam Ash had the best
>    deal @ $239 + shipping. After careful consideration, the Yahama was
>    clearly worth the extra $50 bucks for specs, let alone the noise gate.
 
    	The MT66 also has the noise gate built in, by the way.  I don't
    know about its "tweakability", though.
    
    	Dan
       
770.115Make that snare drum stand still!!!WEFXEM::COTELight, sweet, crude...Fri Oct 26 1990 18:543
    OK, that makes some sense...
    
    Edd
770.116STROKR::DEHAHNNovember 6th: Get out and VOTE!Mon Oct 29 1990 11:087
    
    Edd, not only will thhe stereo image wander around, it can cause an
    audible 'pumping' or 'swishing' sound when used with a good stereo
    source. You really want those VCA's to track together. 
    
    CdH
    
770.117Stereo Ready (Linkable) Mono CompressorsDRUMS::FEHSKENSlen, EMA, LKG2-2/W10, DTN 226-7556Mon Oct 29 1990 15:005
    For the record, the Symmetrix 501 includes a link feature, so two of
    them can be used for stereo compression.
    
    len.
    
770.118New Alesis 3630DCSVAX::COTEcat &lt; man | duTue Apr 16 1991 11:4310
    Gee, just as I start shopping for a compressor Alesis comes out with
    the 3630...
    
    ...seems to have all the bells and whistles. Stereo, linkable, all
    kinds of pretty knobs and a great price. $299. (I bet it goes up.)
    
    ...anyone seen, or better yet *heard*, one? I think there's one in 
    my future.
    
    Edd
770.119Boss RV1000 digital reverbBAHTAT::CARRDave Carr 845-2317Thu Aug 01 1991 09:5913
770.120Boss RV1000 digital reverbBAHTAT::CARRDave Carr 845-2317Thu Aug 08 1991 11:4212
770.121Help needed on Mt-66GOES11::G_HOUSESlave to the GrindSun Sep 15 1991 23:4429
    I have a question for anyone that might know.  I just bought a used
    Audiologic MT-66 compressor and it only had a spec sheet with it, no
    USER manual.  Being the audio buffoon that I am, I can't seem to get
    the thing to work right.  Maybe it's just not applicable for what I
    want to do with it, I don't know.
    
    Here's my setup, I run a mike into a low to high Z into the "input" of
    the unit and then run a cord from the output to my 4-track.  I have the
    threshold control set for about -10db, the compression ratio set for
    about 3:1, the attack set short, the release set high and the noise
    gate disabled.  The problem is that when I set the input level control
    to the point where the LEDs light up showing that I'm getting
    compression the signal distorts terribly.  As far as I can tell, the
    output level control does nothing.  If I set the input level control
    low enough that I don't get distortion in the signal, no compression
    occurs.
    
    I have verified that I get no distortion from plugging the low to high
    Z adaptor directly into the 4-track, and I've played with many
    different settings on the MT66 with the same results.  Both channels
    behave the same way and the "link" switch is disabled (so they are
    seperate).  I also got the same signal distortion when running a guitar
    directly into the MT-66.
    
    What am I doing wrong?  Is this thing only designed to be used with
    line level signals or what?
    
    Greg, very frustrated right now
                               
770.122WAG time...EZ2GET::STEWARTBalanced on the biggest waveMon Sep 16 1991 03:076
    
    
    Sounds like it's generating a line level signal.  Is your 4track
    expecting mike or line level input?
    
    
770.123LEDS::ORSICuz I felt like it....OK!?!!Mon Sep 16 1991 14:4011
    
    	Re .121
    
    	The MT66 is meant to be used at line level (1V) input, not
    	mic level (.1V) The mic level output is 10 times too small for
    	the MT66 input.
    	   If you have channel patching on your deck, patch the unit
    	in there.
    
    	Neal
    
770.124ugh...GOES11::G_HOUSESlave to the GrindMon Sep 16 1991 20:408
    re: .123
    
    Thanks, that's what I was afraid of. 
    
    Excuse my ignorance, but what is channel patching?
    
    Greg
             
770.125LEDS::ORSICuz I felt like it....OK!?!!Tue Sep 17 1991 13:3821
    
    	Greg,
    
    	Channel patching, or a channel insert, is the ability to hook up
    	external processing gear into a specific mixer channel, by way of
    	either a **stereo 1/4" jack, or two 1/4" in/out jacks located near
    	the channel input jack. Most mixers and some 4-trks have them on
    	every channel. Patching places the processing unit of your choice
    	in the post trim/pad/attenuator signal path of whatever you have
    	plugged into that channel, but is pre eq, effect send(s), and monitor
    	send(s), if there are any. Patching inserts are meant to be used with
    	line level units, not mics, instruments, or stomp boxes. In your case,
    	a channel insert would be ideal. I'm not familiar with your deck,
    	so I don't know if it has any.
    
    	** stereo 1/4" jack - TRS, Tip/Ring/Sleeve, where the Tip of the
    	jack is the send, and the Ring is return, or vice-versa, and the
    	Sleeve is the shield/gnd. Check the operating manual of your unit.
    
    	Neal
    
770.126THE way to understand compressionDREGS::BLICKSTEINSoaring on the wings of dawnTue Sep 17 1991 19:319
    For those of you who wonder why some COMMUSIC contributions sound
    like demos and some don't, and who have heard all this stuff about
    compressors but either don't have the foggiest about why they do
    (or maybe you do know what they do but think that isn't important)...
    
    There is an EXCELLENT EXCELLENT article in this month's Keyboard
    magazine about the function and practical usage of compressors.
    
    	db
770.127MIZZOU::SHERMANECADSR::SHERMAN 235-8176, 223-3326Wed Sep 18 1991 02:214
    I used to be a compressor fan.  Now, I feel like spectral analysis is
    the way to go if you have complete control over sound levels.  FWIW.
    
    Steve