[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

1140.0. "DigiTech DSP128 Multiple Effects (FX) Processor" by AQUA::ROST (I feel your innuendo) Wed Jan 13 1988 11:23

    
    Just when you thought it was safe to buy your multi-effects processor,
    along comes another one.
    
    DOD/DigiTech has introduced the DSP-128...rack-mount, MIDI, does
    reverb, digital delay/flange/chorus, compression, etc.
    
    Can do "up to" *three* effects simultaneously (so says the ad).
    
    $399.95
    
    
T.RTitleUserPersonal
Name
DateLines
1140.1Input! Input!AKOV68::EATONDWed Jan 13 1988 11:5610
RE < Note 1140.0 by AQUA::ROST "I feel your innuendo" >

	Can you enter more from the ad?  Sounds real interesting - and a good 
price, too.

	Concerning simultaneous effects - I wonder how flexible it is...  The
DEP-5 can only do certain things together.  I'd love to get chorus, reverb
and compression all at once.

	Dan
1140.2Does it do harmonizing?DREGS::BLICKSTEINDaveWed Jan 13 1988 13:023
    Does this new unit do harmonizing?
    
    	db - who wants to start experimenting with harmonizing tricks
1140.3Vague as usual, King FridayAQUA::ROSTI feel your innuendoThu Jan 14 1988 12:3712
    Re: .1 and .2
        
    The ad was prety vague...
    
    Just a guess, that "up to three" simultaneous effects translates
    to.....some stuff can be done simultnaeously but some can't.  It
    didn't specifically mention harmonizing.
    
    BTW the picture showed a single-space rack mount unit.
                 
    
1140.5ghost tapesANGORA::JANZENto cogitate and to solveThu Jan 14 1988 14:5717
    HOW Long is the max delay?  
    Stereo pan, cirque, ping-pong, are probably all like effects I've
    used on the spx90, in which the amplitude is varied on each channel,
    causing the sound to seem to move through stereo space, except no
    doppler effect, as Chowning has done in his computer music.
    I use fast smooth alternation between the channels to imitate
    the "frankie" (robot prostitute) in "Ruby" from ZBS media.
    Around 10 Hz or less.  LuKas Foss or maybe Adams or somebody
    has had a field day varying the amplitude of speakers all over the
    hall on a miked acoustic piano, using a control tape.
    (like an industrial application: an FM signal on the tape
    is played into a frequency-to-voltage convertor, then the
    voltage can control voltage-controlled synthesis gear, in this
    case, voltage-controlled amplifiers, each controlling a different
    amp/speaker in the hall.  I think it was Foss, and the tapes were
    called "ghost tapes."
    Tom
1140.6WYSIWYGDYO780::SCHAFEROHIO:a river with builtin bath oilThu Jan 14 1988 16:3525
RE: .5

    What you see in .4 is all I know.  The techs and reps are all on their
    way to the winter NAMM show in CA.  I got this information from a very
    pleasant (but also very non-technical) secretary who was kind enough to
    dig up some glossies.

    I have some literature being mailed to me today.  As most music store
    reps, I will be better able to answer after I get the literature (or,
    in their case, attend the NAMM show). 

    Some things I'd like to know: 

	What's programmable (includes maximum delay time, for example)
	Sampling freq. bandwidth
	Visual interface (eg, backlit LCD?)
	No. of rack spaces required
	Is there SYSEX dump capability?
	Better descriptions of strange named FX (eg: cirque, multi-tap)
	What kind of mix controls exist

    Just for starters, of course.  If nothing else, the thing could drive
    the price of the MIDIverb II down to below $300. 

brad
1140.7Oh yeah - almost forgot ...DYO780::SCHAFEROHIO:a river with builtin bath oilThu Jan 14 1988 16:364
    Lexicon is supposed to be announcing a circa $700 reverb unit at
    the winter NAMM.

8-)
1140.8I'm underwhelmed...JAWS::COTE0 for 13Thu Jan 14 1988 16:505
    wow. $700. Such a bargain.
    
    ;^)
    
    Edd
1140.9grump, grump, grumpCTHULU::YERAZUNISHow about a 40 watt plasma rifle? Thu Jan 14 1988 17:222
    What, no pitch shift???
    
1140.10pitch effects for saleANGORA::JANZENto cogitate and to solveThu Jan 14 1988 17:4125
    What of my favorite pitch shifts is the quarter-tone canon.
    delay, 2 seconds, shift up 50 cents.  Actually, I think the SPX
    is out of tune, and I should check it with my home-brew synth,
    which has two crystals, one for a440 and one for quarter sharp
    (I checked the freq with lab equipment).
    Also, dual pitch shift with through, delay .5 sec shifted down a
    fifth, delay 1 second shifted up a fifth, gives instant Hindemith
    canons.
    Pitch shift up a few cents with high feedback gives a pitch bend on the
    ends of notes.
    Pitch shift up a minor second, down a major second, slightly different
    small delays, gives a choral-reading kind of sound when you talk.
    If you use this playing piano, it sounds like you're making lots
    of mistakes.  I used it on the beethoven destruction on commusic
    iii.
    Pitch shift up a fifth and a third give parallel triads, like the
    rocky & bullwinkle theme, as I remember it vaguely.
The spx90 pitch shift is not in perfect tune.  In fact, the interval
    changes depending on the absolute pitch input.  Perhaps this is
    due to an effort to splice on positive zero-crossings.
    Dual shift up & down an octave gives a gamelan big heavy sound
    that's out of tune.  
    Certainly, there's a honky-tonk piano in there, but I've never
    done it.
    Tom    
1140.11Glossy reprint - DSP-128DYO780::SCHAFERif (bucks .GT. 0) call MUSIC_STOREMon Jan 18 1988 17:06123
1140.12From the owner's manualDFLAT::DICKSONNetwork Design toolsMon Feb 08 1988 01:0098
I went to Daddy's in Manchester, NH and asked about the DSP-128.  They
opened a box that had just arrived and let me peruse the manual.  The
following information is from this manual, which was labelled
"preliminary" and is dated 15-Jan-1988.  The manual is not very large.

General specifications:
	Inputs and outputs are quarter inch jack, balanced or unbalanced.
	Stereo input and output.  Levels can be switched between +4 or -20 dB.
		The max output level is +18 dBv referenced to .7 volts.
	Both dry and mixed output are available.
	THD less than .08% at 1kHz
	16 bit linear PCM conversion, 90 dB SNR
	Freq response:
		Dry 20-20kHz plus or minus .5 dB
		Wet 20-12kHz plus zero, minus 3 dB

Programs are created by selecting one algorithm, then setting
parameters that affect parts of the algorithm.  The available algorithms
are as follows:

	0	mute
	1	small room, delay, filter
	2	medium room, delay, filter
	3	large room, delay, filter
	4	gated reverb, filter
	5	reverse reverb, filter
	6	delay, filter
	7	multitap delay, filter
	8	chorus, delay, filter
	9	flange, delay, filter
	10	hall, filter
	11	live medium room, filter
	12	live large room, filter
	13	multitap delay, reverse reverb, filter
	14	medium room, delay, chorus
	15	large room, delay, chorus
	16	bounce, filter
	17	stereo image, filter

Notice that this list is not the same one as appears on the glossy, even
for algorithms up to 17.  (Why just 17?  Maybe I skipped a page.  I was
kind of in a hurry.  On the other hand, that glossy was probably prepared
months ago, while the manual is dated within the last month.)

Most of the algorithms are pretty obvious.  I didn't have time to copy down
all the parameters for each algorithm, so I picked a couple representative
ones.  The parameters for "medium room, delay, chorus" are:

	Pre-delay		0-90 ms
	Decay time		.3-28 sec
	Reverb level
	Delay range
	Delay time	0-999 ms  (suggests max delay available is 1 sec)
	Delay feedback level
	Delay level
	Animation velocity
	Animation distance
	Chorus delay time 0-60 ms
	Chorus level

For comparison, here are the parameters for "large room, delay, filter":

	Lo pass			400Hz - 12kHz
	Pre-delay
	Initial reflection level
	decay time
	reverb level
	delay range
	delay time
	delay feedback level
	delay level

It comes with a bunch of factory preset programs.

Now the fun part.  MIDI support:

	You can dump and restore all your settings through MIDI.
		(There were some SYSEX formats in the back of the book.)
	MIDI PROGRAM CHANGE selects a program.
	MIDI continuous controllers can be assigned to control "many" of the
		parameters.

This continuous controller business is interesting.  The manual did not say
what "many" means, by the way.  Once a controller is assigned to a parameter,
it stays assigned regardless of program change.  If a controller is assigned
to a parameter, the controller supercedes what the current setup indicates for
that parameter.

The DSP-128 is one rack unit high.  All connections are on the back.  Front
panel contains three level knobs (input, output, output mix), a few buttons,
a not-very-large numeric display, some LEDs indicating which effects are in
use by the current program, and a small level indicator labelled "headroom".
It looked like most displays were various numbers, rather than English
messages.  There was a sort of cheat-sheet printed on the top cover.

It can rack mount or use by itself.

Daddy's price, $330.
1140.13DFLAT::DICKSONNetwork Design toolsMon Feb 15 1988 18:263
re .11

Why are you "not so sure it's that great a deal"?
1140.14Just gossip, I guessDYO780::SCHAFERJust another roadie.Mon Feb 15 1988 18:559
RE: .13

    I'd heard some not-so-nice things about DOD in general.  Have never
    heard one of these, though.  I intend to as soon as I'm within 80 miles
    of a decent music store (which isn't very often, unfortunately). 

    Feel free to prove me wrong.  It looks good on paper.

brad
1140.15Can't afford not to give it a listen.BOLT::BAILEYSteph (stef') BaileyTue Feb 16 1988 16:067
    There were several favorable reviews (or at least ``first
    impressions'') of the DSP-128 on the Usenet.  Both claimed a clean
    sound.
    
    Sounds like it's worth checking out for effect-less people.
    
    Steph
1140.16My assesment.ROLLIN::BAILEYSteph (stef') BaileyThu Mar 10 1988 16:1979
    Well, here's the subjective review, plus a few gotcha's
    
    First, how does it sound?
    
      Well, this is my first effect, so I don't really have a metric,
    but by listening directly to the output of the unit (the sales people
    look at me like I'm nuts when I ask to do this), i.e. wet only:
    
      1) Reverb sounds very good to me.  There is some (barely) perceptable
          garbage at the beginning of the large room program.  The
          reverses, and gates are good.
    
      2) Delays sound a little muffled since the beast only has 12KHz
          frequency response.  The multi-taps are good.
    
      3) Choruses and flanges are not what I expected.  At first, I
          thought they were lousy, but then I started experimenting
          with different sounds, and that helped.  Many sounds just
          don't seem to benefit from chorus or flange.  I don't know
          if this is par for the effects, or not.  Again they sound
          somewhat muffled due to lack of frequency response.
    
      4) The ``bounce'' effect is neat.  I could well imagine using
          it, despite its odd nature.
    
      All in all, I am satisfied with the sound.  Certain sounds can
    make certain settings sound terrible, but I'm sure that's true of
    all effects.
    
      Now the interesting features:
    
      1) Any parameter may be varied by an arbitrary MIDI real-time
          controller input.  There is a single, global set up which
          describes which controllers vary which parameters--too bad
          this is not on a per-program basis.
    
         Unfortunately, not all parameters which are variable are smoothly
           so.  Particularly, many parameters cause a god-awful racket
           if you vary them while the output of the effect is sounding.
           All the reverb parameters are silently variable, which is
           great, and virtually none of the rest are--except for the
           delay feedback factor.
    
         Even despite the glitches in this feature, I have already grown
           to like it very much.  It adds a great deal to my performance.
    
      2) The configuration is dumpable and loadable via SYSEX.  This
           is a big win over other MIDI FX boxes that I have seen.
    
         Interestingly, and dangerously, you can load the system micro-code
           using SYSEX.  This is presumably for easy upgrade, but it
           also allows trojan horse writters to zap your DSP.  I wonder
           if it needs the micro-code to load the micro-code.
    
      3) Having only ``up-down'' keys with which to change programs
           is a massive pain in the neck for just fiddling around.
           You TX81Z owners know about this.  In general, the interface
           is resonably easy to memorize (you have to memorize some
           two letter abbreviations for the patch names), but very slow.
           Maybe I'll write a config editor for my ST.
    
      4) There is no such thing as an ``edit buffer''.  Any changes
           made are made to the stored copy of a program.

    
    In summary, I am very pleased with my DSP-128, so far.  It has some
    sonic flaws, but since it is an effect, and not an instrument, I
    don't really find them significant.  The real-time feature is of
    inestimable value.
    
    Finally, I hope, since the code is easy to update, that they will
    do it!  I want to be able to vary chorus and flange parameters (as
    well as delay time) in real time without getting a "GRRRRONK" at
    the output.
    
    As usual,  I'd be happy to receive visits or further questions from
    interested parties.
    
      Steph
1140.17DSP-128 Is Discontinued!!!AQUA::ROSTHum-dum-dinger from DingersvilleThu Dec 01 1988 19:0221
    
    Are you ready??
    
    The DSP-128 has been discontinued and they built the last one on
    Oct.28th!!!
    
    Now the good news, the DSP-128 PLUS is being introduced.
    
    Same price $429 list.  Now has bandwidth to 20KHz (not 12).  Now
    can chain up to *four* effects (hmmm, have they seen the ART and
    Alesis boxes?).
    
    Also out for $529 *with a foot controller*, the GSP-5, a similar
    unit for guitar processing.  15KHz bandwidth, *five* simultaneous
    effects:Flange, delay,multi-tap, parametric EQ, chorus, verb and
    distortion.
    
    *All* parameters fully programmable, of course.
    
    Now will we see DSP-128s blowing out for $150 ???  8^)  8^)  8^)
    
1140.18DSP128 foot controller ??'sASAHI::COOPERVoid VisageMon Feb 06 1989 19:4819
    Yeah, you probably will...
    
    I picked one up at Daddy's in Salem for just over $200 with a 6
    place rack....
    
    ;^)
    Now...
    
    Can someone educate me about foot controllers ?
    I don't know much about midi, and I'm a guitar player, so I need
    an easy to use foot switch to enable me to:
    
    a) Bypass the unit
    b) Easily pull up my fave programs (quick and noise-less ?)
    
    I'd appreciate any instruction I can pick up on midi, and controllers.

    Thanks !
    Jeff
1140.19DSP128-->DSP128 Plus-->MSP4-->?????AQUA::ROSTShe's looking better every beerThu Feb 16 1989 17:2415
    
    Just to confuse things further...
    
    DigiTech has already shown big ads for the DSP-128 Plus as well
    as the GSP-5, well now in the March "Guitar Player" is an ad for
    an MSP-4.  
    
    Which supposedly is a MIDI controllable four effects at a time box.
    Which sounds like a DSP-128 Plus to me....no price or other info
    in the ad.  It even *looks* like a DSP-128.
    
    I give up, I can't keep track of all this stuff anymore.  Someone
    wake me up when used MV-IIs start going for $150.
    
    
1140.20buzzz......VIDEO::BUSENBARKThu Feb 16 1989 17:344
    	Well start waking up,one eye open?  :^)  as there was a MVII for 
    $175 in the want ad advertiser last week.  I think Digitech call's
    it cost reduction and/or advanced developement. let's saturate and
    fill the market.....a little more.... 
1140.21Digitech emerges from the packDREGS::BLICKSTEINAerobocopThu Feb 16 1989 17:4913
    > I think Digitech calls it cost reduction and/or advance development.
    > let's saturate and fill the market... and a little more..
    
    More power to them.
    
    I borrowed the IPS 33 (Intelligent Harmonizer) manual and was rather
    astounded at what that thing is supposed to do for what it costs.
    
    I still haven't tried one as the stores just can't seem to get them
    but if it's at all decent, and I hear it's more than that, it'll
    be on my "to buy" list.
    
    	db
1140.22upgrade your DPS128SUBSYS::ORINA waist is a terrible thing to mindThu Feb 16 1989 18:035
Eddie Fritz at Wurly's tells me that a new software prom for the DSP128 will
turn it into a DSP128 Plus for about $25.00 and it's supposed to be user
installable.  (508) 754-5271 for further info.

dave
1140.23HAMER::COCCOLIjust gimme Park AvenueThu Aug 17 1989 01:189
    
      I called Wurly's about the aforementioned chip. There is a three
    month wait for it. Not that I own a DSP, but I'm looking.  Also
    along this line is the MSP-4, for about $250. I'm not sure of the
    bandwidth. I tried the new Harmoney Machine from digitech. It's
    trash, IMHO.
    				rich
    
    
1140.24Strange stuff with DSP128.CSG001::ROACHWed Jan 10 1990 01:2919
I'm going to add a new theme to this topic. 

Last weekend, in my continuing quest to get the most out of my DSP128, I 
noticed a few strange things. First, I had both the right and left outputs of 
a TX81z plugged into the corresponding inputs of the DSP128, but I only had 
the left output plugged in. This is supposed to provide a mono out according 
to the manual ( I Think). Guess what - only the left channel made it through 
the DSP128 - no output from the right input. I guess this means that the 
DSP128 is not smart enough to mix the signals to provide a single output.

When I did plug both outs from the DSP128 into the amp, I only got signal with 
the effects in, there was no dry component to the signal at all. How do I 
know? When the mix was all the way to the dry position - no signal. All the 
way to the wet side - very loud. This same stuff does not occur when only 
using this in a mono application - one in, one out.

Is this thing supposed to work like this? The manual doesn't say at all.

Geoff