I swear this is the last I will say on the subject of a simple mixer. It's
incredible how much discussion we've been able to generate. Paul, your head
is probably spinning like Linda Blair's<g>.
>
> From: JWBarlow@...
>
> Hi Paul (everyone),
>
> Mixer is sounding great! I hadn't even thought about output pots;
> so here is
> my two cents (I'm with you, Paul, on 6 knobs, 8 jacks).
Doesn't Paul's design call for 7 knobs (3 input levels x 2, 1 dual ganged
output level), 8 jacks? Since a 2U panel in standard spacing has room for 8
pots/switches and 8 jacks max, that leaves 1 spot open for a switch, or for
a second output level pot, but not both.
> 1) a switch which defeats output level pot on output 2 or (better)
> 2) a DPDT 3 position switch which defeats either output level
> control 1 or 2
> (both active in the middle position).
> 3) Input 1 to NC input 4
> input 2 to NC input 5
> input 3 to NC input 6
> (do you guys see what I'm on about here?)
You are saying to normal the inputs of mixer 2 to mixer 1. I like the idea,
but I can just hear Paul: "That's a s***tload of wiring!" I'd probably make
the mod anyway.
> Then you'd have a 6x1 or (3x1)x2 or 3x2 (stereo output) mixer: the full
> utility mixer!
You know, it seems like we started talking about a 6x1 mixer, but the 3x1x2
configuration seems much more useful to me. I'll rarely need more than 3
inputs for a CV mixer, and will rarely need more than 4 inputs for an audio
mixer. That's not considering the final output, because I expect that there
will be a nice final output mixer with VC panning and maybe a headphone amp
later.
Given the above, my vote would be to optimize for 3x1x2 operation. Now what
does that mean? The question in my mind is "How necessary are separate
output level controls for dual 3x1 operation"? The answer to that depends
somewhat on the direction some future modules in the system take. For
example: Paul has mentioned ideas for future modules like a single space
dual VCA, perhaps 1/2 linear and 1/2 exp. response.
This could be built 2 ways: with CV and audio input attenuators and without.
If most modules have at least 1 CV and 1 audio attenuator (if applicable), I
may not need output level controls on the mixer at all! Certainly, dual
ganged outputs would not inconvenience me, because I could just crank the
output pot, and set overall gain for the mixer at the input attenuator of
the module I'm patched to. However, if you have a lot of modules without
input attenuators, you'll end up wanting separate mixer level controls.
OK, I'm gonna shut up now about mixers, and just buy whatever Paul builds!
Dave Bradley
Principal Software Engineer
Engineering Animation, Inc.
daveb@...