Conference napalm::commusic_v1

    I hear you regarding a new standard of stereo, saving mixer channels
    etc.. would be a major problem trying to record two signals on one
    tape track, however.. do you envision carrying pan position info
    electronically, or just depending on the mixer's pan control for
    that channel ?  I see a problem with the 'pan' concept.. rather,
    it would need to pan TWO separate signals.
    
    I just finished a piece where all parts but
    two required stereo.. stereo snare, stereo plucked bass, stereo
    sampled bicycle sprocket as hihat equivalent, stereo choir, stereo
    arpeggiated elec piano part.. used up all the tracks on the 8track
    as well as forcing me to use both (stereo) SGUs with MIDI-FSK sync..
    really eats the tape and mixer channels, but that's what this piece
    required, versus just panning a mono signal to where you want it
    left-to-right.
    
    I get confused re your wiring question.  Most if not all my
    line-level (RCAplug) cables are stereo.. two mono cords molded
    together, splitting off into two RCA plugz at each end.. I even
    use RS 4-channel cords.  Do you wish to use ONE CORD (signal/
    ground) to carry one or two signals ?  Sort of multiplexing on one
    cable ?  Your picture implied you had two separate conductors in
    the cable..
    
    karl

    re .1 - I think Dave is assuming the use of "tip/ring/sleeve" phone
    plugs and jacks, a la stereo headphone wiring.  The cable is three
    conductor, with one ground and two signal lines.
    
    The problem is that while a jack can tell if something's been plugged
    into it, it can't tell if the plug is two conductor or three conductor.
    I suppose somebody could work up some electronic hackery that could
    sense if the "ring" contact was grounded (to the "sleeve"), and
    in that case sum the two channels and send them to the tip contact.
    Otherwise, one channel would go to the tip and the other to the
    ring.  This probably could be done for output jacks, but I'm not
    sure it could be made to work for input jacks, where you want the
    incoming signal (on the plug's tip) to be routed to both the tip
    and sleeve contacts on the jack; note that the ring contact is
    grounded to the sleeve contact by the mono plug (whose "ring" *is*
    the sleeve).  
    
    A possible solution to all this is to require that *all* plugs be
    tip/ring/sleeve format, with mono signals wired to both tip and ring.
    
    The common ground might cause a problem with some kinds of circuits?
                                                                          
    len.
    

    
    Re: .2
    
    Peavey uses T/R/S wiring for single jack pre out/power amp in on
    many of their amplifiers.  What they did is if you want the pre
    out *without* patching back into the power stage you put a two
    conductor plug *halfway* into the jack.  
    
    If you plug a two conductor plug *all the way in* you only feed
    the power amp input.  
    
    A regular T/R/S Y-cord like you would use on a stereo wire guitar
    is needed to actuallyuse as an effects loop.
    
    This system has one major downfall, though....inserting a plug only
    halfway does not make an overly reliable mechanical connection.
    
    
    The idea of shorting tip and ring on mono cords means that such
    cords are incompatible with current T/S two condcutor cords (i.e.
    tip will short to sleeve).  On the  other hand, T/R/S cords work
    fine in two conductor syatems, with the ring shorting to sleeve.
    
    Another thing to think about: on stomp boxes (I know you love 'em
    Dave) a T/R/S jack is often used on the input to act as a power switch.
    When a T/S cord is inserted, the ring to sleeve short completes
    the power cicuit.  This feature guarantees power is off when you
    unplug from the input of the box.   This would not work with T/R/S
    cords, particularly if tip and ring were shorted for mono operation.

    

    I'm going to try to get three responses into this note...
    
    Basenote: Dave, I with you on this one, there really should be a
    standard for shipping stereo signal-pairs around.
    
    .2 (Len)  Going by what I've seen happen in computers, and in other
    areas of musical electronics (mini-phone plugs on AC adaptors!),
    I wouldn't try to overload an existing standard with an essentially
    incompatible one.  All the old equipment in the world would have
    serious problems, the documentation effort would be painful, etc.
    	I think we need a new standard, with a new connector.  It should
    be upwardly compatible with a 4-channel version.  One thing that
    I would really like would be only one cable running between my
    mixer and a stereo effect box.  I have seen some European tape decks
    that replace the U.S. "standard" of using 4 RCA cables with just
    one single DIN cable.  Nice, very nice.
    
    Basenote and .1: Like Karl, I use molded-pair RCA (phono) plug cables.
    I use these everywhere I have a stereo signal, despite the fact that
    just about all my equipment has 1/4 inch phone-jacks.  I use a whole
    lot of Radio Shack adaptors that convert my phono plugs to phone
    plugs.  This sounds ugly and kludgy, but the new adaptors are really
    small and all metal, the resulting cord looks just like the 'two
    guitar cords in one" that you wanted.  Those new adaptors really
    do make the phono plug plus adaptor assembly as small as a regular
    phone plug.
    
    	Eirikur	(Currently re-cabling his setup)
    
    
    
    
    	

    I agree with .1, and have also wondered why this hasn't happened
    sooner/more often ... I find that in most cases (live performance,
    that is) I tend to do the same thing with my stereo gear: L goes
    into one channel on the mixer, panned hard L, and R goes into the
    next channel, panned hard R.  then, the send fader, and FX controls,
    for L and R are set the same.  I remember asking around at stores
    ... "Isn't there a mixer where each "channel" is really stereo?"
    Sure, for some purposes (such as recording) you want the flexibility
    to individually control L and R from a given SGU, but for those
    cases where things are simpler (and you want faster/easier setup,
    easier control of a stereo instrument, etc) ... much easier to bring
    up or down ONE fader to turn up my D-50, or alter ONE FX knob to
    add more reverb to my Tx-802, or whatever.
    
    		-Jim

    
    There are stereo input and output mixers, of very high quality and
    a reasonable number of channels. But they are expensive, and most
    lack the multiple effects busses you guys demand.

    Dave,
    
    You could do it easily with one cord, no adapters. However, Len's
    point was overlooked, and a good one. If you use standard 2 conductor
    plus ground balanced cable, then it might work for some units but
    not for others, as some manufacturers ground the return line and
    others float it. There is no standard. However, you ca avoid this
    by using balanced 4 conductor cable with ground, and wye-ing off
    each end. Conquest makes these. Send mail for more info.
    
    CdH
        
    
    

    To all,
    
    If you want me to answer your questions, you have to avoid things
    like "ground" (isn't that what I put my feet on - usually), "float"
    (please specify D, F, G or H), "conductor" (gee, haven't ridden a
    train in years).
    
    I am ashamed to confess that my knowledge of electronics is probably
    significantly inferior to most 14 year olds these days.
    
    I use guitar cords for my keyboard stuff.
    
    > do you envision carrying pan position info electronically, or just 
    > depending on the mixer's pan control for that channel ?  
    
    I plan on plugging something into to INPUT.  If what I plug in
    is a stereo cord, the "pan" knob acts like a "balance" knob.  If
    what I plug in is mono, the "pan" knob acts like a "pan".
    
    The 'detection' problem that Len pointed out could be solved 
    (I think) by a switch - i.e., you have to "tell it" whether it's
    stereo or mono. 
    
    > I see a problem with the 'pan' concept.. rather, it would need to 
    > pan TWO separate signals.
    
    That's NOT what I want "my" mixer to do.   When I have a stereo input, 
    I don't need to "pan" anything.  Both signals get passed thru at their
    input levels.  In fact, in most cases, I really don't even need a
    "balance" control, so maybe the "pan knob" is just inoperative with
    a stereo input (does that make the 'detection' thing easier?
    
>    I get confused re your wiring question.  Most if not all my
>    line-level (RCAplug) cables are stereo.. two mono cords molded
>    together, splitting off into two RCA plugz at each end.. I even
>    use RS 4-channel cords.  
    
    I currently use guitar cords ("phone plugs" - see I know *some* of
    the names for these things) for everything.  I suppose I could
    could start using a stereo cable, although I generally make my
    own cords (are you impressed?) these days, and whereas I can find
    "guitar cord" in reels, I haven't seen "stereo cord" (other than
    "headphone cable") anywhere.  I haven't looked very hard though.
    
    Can I get "good" stereo cord suitable for stage/studio use that I can
    run in long lengths (up to 20 feet)?
    
>    Do you wish to use ONE CORD (signal/
>    ground) to carry one or two signals ?  Sort of multiplexing on one
>    cable ?  Your picture implied you had two separate conductors in
>    the cable..
    
    Y'know what I REALLY want?
    
    Yes, I want ONE CORD.  But I want it to do EVERYTHING.   I want to
    have one cord (MASSBUS????) coming from my keyboard rig, that plugs
    into a big connector coming from my rack.
    
    And ideally what I'd like to have that one cord carry not just stereo
    audio, but MIDI, power and some control lines (for pre-midi efx and
    such).
    
    That's the ideal.  The question is what is achieveable?  At the
    moment, I'm just snaking cords together (no, I do not snake power
    with audio or MIDI) but that's pretty messy.
    
    Are there places that sell cord for more than 2 conductors (quad cord?)
    
    I know that video "dubbing cable" uses 4 phono plugs, but pre-wired
    dubbing cables aren't available in nearly the length I need.
    
    I think for the moment, it would be fine for me to just have a 4
    conductor cord, to which I would snake a MIDI cable.
    
    	db

    I'm interested - post more.
    
    I presume I can pack any of ground, audio, control and
    MIDI into this buss.
    
    But what about shielding?  Don't I have to get cable that's properly
    shielded in order to have some reasonable protection from noise?
    
    	db

    About the only noise you're going to get is from ~60 cycle.  I've never
    had trouble with, say, my ESQ-M making my TX sound grungy. 

    I doubt that there's enough of a signal in a MIDI cable to cause
    anyone any trouble.

    An aside that I didn't mention before, since I really haven't thought
    this thru.  I would probably end up running multiple cables thru a run
    of loom or shrink wrap (ie plastic hollow tube) - one for line signals,
    one for MIDI, and one for power (if needed). 

    Gotta go - I'm fighting a chimney fire here at home (sigh). 

-b

    ....seems to me that some of the 25 pair cable used in networks
    would work. Small diameter, multiple twisted conductors, color-
    coded...
    
    Oh look! There's 50' of the stuff under my desk just sitting there...
    
    I make all my audio cables outta coax. No idea if this is good,
    bad or ugly but it appears to work real well. I use it for patch
    cords, speaker cable... 
    
    Edd

    
    Another thing about having a buss cable....
    
    All the manuals that I've read told me to keep the inputs to my
    8-track as far away as possible from the outputs.  I have never
    really noticed any problem of bleed (or whatever), but if you have
    a huge cable with all of the ins and outs running together, it is
    possible you could get plenty-o-bleed.
    
    Ashley

    re .-n, where somebody said a TRS jack was used to turn power on
    for a stomp box when a plug was inserted: actually, these use switching
    jacks, not TRS jacks.  You can get jacks that will switch up to
    DPDT upon insertion, and the switched contacts are electrically
    isolated from the plug's tip or sleeve.  Such a jack would switch
    regardless of the type of plug inserted.  A clever designer might
    use a TRS jack for the same purpose, but could be defeated by a
    TRS plug (for example, if somebody had a TRS plug handy and neglected
    to short the ring and sleeve together when they built the cable).
    I suspect the cost of a two conductor switching jack is just about
    the same as a three conductor (TRS) jack; the former has one more
    part, and so might be a tad more expensive.
    
    I've been doodling "functional specs" for a stereo MIDI oriented
    mixer, with exactly the sorts of features desired by several
    contributors to this discussion.  I suppose this means I'll have
    to clean up my notes and post a proposal?
    
    If only somebody would *build* some of this stuff.  Anybody with
    a lot of venture capital wanna "invest" in LerdsBimCo?
    
    Edd, coax is designed for high frequency transmission line use.  
    I don't know if it has desirable capacitive properties for audio
    (relatively low frequency) use.  Consult a real electrical engineer,
    not a former software engineer turned architect.
                                               
    len.
    

    Coax has another useful feature (a result of the transmission line
    design but useful by itself):
    
    	COAX REJECTS HUM!
    
    External magnetic and electric fields tend to be shielded from the
    inner conductor with a coax setup.  The shield gets a circulating
    current and heats up some, but it _tends_ to protect the inner core
    (and the signal).  This assumes an UNbalanced signal (like 1/4"
    phono plug).  For a balanced line use TwinAx cable to get the same
    shielding effect.
    
    Coax works fine for normal audio use.  It's usually overkill (costs
    more per foot) but if you got it, there's no reason not to use it
    (assuming you're not in a capacitance-critical application - which
    should be rare to nonexistent in a well-designed audio system).
    
    	-Bill

    Soldering the braid is a pain in the tuckus...
    
    Which gets me to thinking, am I doing it right??? I solder the 
    braid to sleeve and the center conductor to tip on mono 1/4"
    phone plugs...
    
    'zat right?
    
    Edd

    Yep, center conductor to tip.
    
    There's a neato little tool that unbraids the braid.  You might
    want one if you are going to make a lot of coax cables.
    
    	-Bill
    

    
    Computer cable is designed with mainly foil shielding, which can
    be an excellent shielding materioal, but it doesn't flex very well.
    Thus the shielding properties degrade over time. It was designed
    for semi-permanent installation. Not like what you guys need.
    
    I've got all sorts of lit at home about multiconductor connection
    cabling, like for mike and speaker snakes and sound reinforcement
    system interconnect. I'll try and remember to bring it in and post
    some examples and prices.
    
    Edd, yup, tip to white or red and sleeve to braid or drain wire.
    For TRS, it's w/r to tip, black to ring and b/d to sleeve. Balanced
    to XLR it's w/r to #2, black to #3, and b/d to case. Unbalanced
    XLR it's w/r to #2, black to #1, and b/d to case.
    
    CdH
    

    
    Re: .13
    
    Not to start a rathole, but all the stomp boxes I have ever worked
    on use normal 3-conductor phone jacks, wiring the ground return
    of the power supply to either the ring and wiring real ground to
    the sleeve.  That way, unless a two conductor plug is inserted,
    the power supply ground return path is opened and power is therefore off.

    I have seen switching jacks but never in a stomp box...Most likely
    due to cost.
    
    BTW if you used a three conductor cable with such a stomp box, it
    would still work as long as the *other* end of the cable was plugged
    into a two conductor jack (thus again shorting ring to sleeve).
    
    

    re .18 re .13 - yer prolly right.  It occurred to me that the power
    supply ground and the signal ground are typically the same in a stomp
    box, so the isolation provided by a switched jack isn't worth the
    additional cost - you'd just wire the switch contact to ground anyway
    to complete the power supply circuit, something the ring/sleeve
    contacts do quite nicely on a two conductor (ringless) plug.
    
    len.
    
    

    I believe the technolog you guys want is hear today, it's just
    expensive. You want to run 10 instruments in stereo, buy a 
    24 track stereo board. As far as cabling, you can always use
    a snake to run all your line and mic levels. Of course, AC power 
    cords, and speaker cables should be kept away from such signals,
           
    I have seen lots of snakes with upto 16 1/4" phone jacks on each end,
    mainly geared towards keyboard applications. These could be used
    for the type of setups described here. Microphone cable has 2 inner
    conductors and a single ground, and is ideal for stereo cables if
    this is what you need, but when it comes to running many line levels
    together your better of with a snake with individual grounds for each
    signal, especially where the 2 signal lines need to split with 1ft
    or more of slack beyond the split. You could always make up your
    own snake with each cable selected for required length and mix mono
    and stereo lines within the snake. The whole thing could be held
    together with zipper wrap, tie wraps, etc. This could be a real
    time saver at setup time. If everything is properly labeled, it would
    make it easy for roadies and the like to help set up your gear.
    
    Mark Jacques
    

    re .20 - by this argument, stereo preamplifiers were never necessary.
    Yes, you can use 20 channels to handle 10 stereo instruments, but
    the control setup is inconvenient to use.  There is much needless
    duplication (e.g., two separate volume sliders, two sets of switches,
    which must be properly set).  A stereo input could be accommodated
    by a single channel frame, with a single slider, single routing
    switches, and a pan control.
    
    I already do this through my 16 channel board.  I have 8 channels
    committed to 4 stereo sources, and 4 channels committed to 2 stereo
    effects returns, with 4 channels left over for mono sources.
    
    I want a *real* stereo board.                               
    
    len.
    

    re: .20, .21
    
    Mark,
    
    The technology is NOT here today.
    
    While your "solution" does give approximately the same signal paths,
    I think lost of track of the point of it all and ended up in
    a chicken & egg cycle.
    
    The reason why I want what I want, is so that I don't HAVE TO do
    all the kludgey things that you've proposed, which is what I'm
    sure we're ALL doing in the absence of true stereo-input mixers.
    
    Soon I will have a virtual 24-channel mixer (a 16 ganged with an 8),
    but in fact, all I need is an 8-channel mixer with stereo channels
    which I'm sure could be produced for about half of what I will end
    up paying, and could be used with about a 3rd of the cords.
    
    Also thanks to Len for producing the clear and simple statement of
    the advantages that I was unable to do myself.
    
    	db
    
    p.s.  Anyone wanna form a company?  
    
    p.p.s.  I'm only half joking about forming a company - I think we
    	    could kill what's out there now in the price/performance
    	    ratio just by going to "stereo channels".  Think about it.

    The first review of your mixer in Keyboard would complain that you
    don't provide mono patch cords that are compatible with your mixer,
    and mono inputs.
    Tom

Stereo mixers aren't new.  They have been around in radio stations for years.
The one I have used (brand name "ADM") had different kinds of modules you
could drop in.  All modules had a linear fader, cue, two output routes,
and so on.  The mono modules (for microphones) had pan-pots which the stereo
modules lacked.

The patch cords were all mono.  To patch a stero signal used two cords.
Standard patch bay.  Of course, everything was set up so that with no cords in
at all, the most useful arrangement of connections happened.  (The patch panel
is not part of the board, though.) 

A book I have on radio production has a survey of several brands of such
mixer, and they were all like this.

Radio consoles have to be easy to operate, as they are being used live, in
real-time, by a highly distracted person.  Maybe this is why they go to the
trouble of putting in stereo modules. 

    re: .23
    
    As I've mentioned previously, my hope is that it would somehow detect
    a mono cord as such and do the appropriate thing.
    
    re: .24
    
    Are these devices affordable by the regular music guy?  Are they
    capable of withstanding the rigors of the road?  Do they have EQ?
    Effects sends/returns?  Solo boosts?  Monitor sends?
    
    In short.  Are we talking about the same kind of mixer?  I'm talking
    about something that can and WOULD be used by musicians, not radio
    stations whose needs I would expect to be significantly different.
    
    	db

    Oh yeah, I remember when my college radio station went stereo, and
    I mixed down a collage of classical recordings in stereo.
    Of course, phonographs, tape recorders and network in radio were
    stereo sources.  The usual stereo sources in home production are
    the effects boxes, and maybe new samplers here and there.
    So it may be best to have a mono side and have the effects buses
    return to stereo channels.
    Tom

    Radio station boards typically do NOT have production board features,
    like EQ, mute, effect send/recieve, roadability, etc.  They are
    designed to be hardwired & bolted into the radio station and then 
    NOT MOVED!  EVER!  
    
    There _may_ be a market for "stereo gig/production boards" but I'm
    not sure if it's worth exploiting.
    
    	-Bill

    
    There are many stereo input/output boards on the market, but they
    don't have *every* feature you are looking for. They might have
    one effects bus, not 3 or 4, and that one might be global, ie for
    all channels or no channels. They usually don't have 3 or 4 band
    quasi-parametric eq like your recording board does, maybe just bass
    and treble controls, or three band fixed eq. I think the biggest
    'missing link' would be the lack of multiple, assignable effects
    busses (send and return).
    
    CdH
    

    I think boards should be modular and expandable in at least two
    directions. 'Horizontally' and 'vertically'...
    
    Horizontal expansion would allow you to add channels and submix
    groups to your heart's desire.
    
    Vertical expansion would consist of a 'buss' that you could plug
    modules into. Some modules would integrate on a per channel basis
    and not become part of the buss traffic. (i.e. A parametric eq
    module that only effected channel n.) Some modules would be 'on
    the buss' and would share *some* of their control facilities with
    like modules. (i.e. An effects buss where the same effect would
    be used on more than one channel.)
    
    Anyone got some money?
    
    Edd 

Top-end boards are pretty much as you describe.

The ADM board I used was expandable horizntally.  Each slot had a fixed effects
loop of its own (no loop level controls in the slot).  It had three busses, now
that I think about it (I wrote the manual for it for new operators).  Not
counting CUE, which was mono. If you wanted fancy effects returns, you would
have used the extra busses and bring the returns back in through another
input.

The way we had it set up, there was a stereo 4-band parametric EQ in the
effects loop on one of the channels.  Oh, there was another MONO buss, which
combined the L+R of one of the other busses.  We used to use this to feed a
mono version of the Met Opera broadcasts over a phone line to some poor college
AM station somewhere. 

No sub-mixers, though.  At least not the way this one was configured.  I don't
see why you couldn't wire up the standard modules to do that, though. The board
in the "B" control room was more for production of stuff onto tape for later
broadcast, and it had more inputs (especially mic inputs). But in both rooms,
all non-standard routing was done on the patch panel, not by little routing
buttons on the board itself.

This thing was not going anywhere.  It was built into the desk-top, and
had zillions of wires coming out of it down under the raised floor and over
to the patch panel in the rack.  (three 19" racks, six feet high, mostly
containing transmitter controls, the patch panel, the satellite receivers,
power supplies, and the Civil Defense alert receiver.)

I have seen some really monster boards used by travelling groups.  Things
in that class might be modular.  Radio stations have different needs, after
all.  (I remember a time when I had to record two programs at once coming
in over the satellite, while simultaneously running another program out
through the transmitter.  In your typical recording situation, you do one
thing at a time.)

My preditiction is that as stereo sources show up more, the recording mixers
will follow.  But a synth with more than one output isn't really "stereo".
Samplers and effects are the only things around now.

    I think there's another opportunity being missed, which is to design
    a board mostly for use with line level synth and sampler sources.
    Such a board would dispense with per channel EQ (generally the
    excpetion rather than the rule for synthetic sources) and feature
    a *lot* of effects sends/returns.  Only a few mic inputs need be
    supported.  Most boards today feature a lot of stuff I don't need
    and lack a lot of stuff I do need.  I think the trend is toward
    more synths and less acoustic (mic'ed) stuff, and the mic'ed stuff
    could be readily supported by a submix board of traditional layout
    that dumped its outputs onto the main busses.
    
    len.
    

    Uhm, ever heard of the M160 or M240?  16/24 channels, no EQ, and 4 FX
    send/rtns (stereo).  4th is switchable pre/post fader.  Channels 1&2
    accept mic or line level signal. 

    But inputs ain't stereo.  And FX sends ain't stereo.  8-(

-b