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Subject: Re: VC EG (breadboard) -- new idea

From: JWBarlow@...
Date: 2000-02-13

In a message dated 2/12/2000 11:12:12 PM, DAVEVOSH@... writes:

>the single
>input vc to all parameters ( or just adr as desired) has merit. from my
>s∗∗∗∗
>days, i used this feature on their adsr eg regularily. in fact, in a less
>deluxe diy version, you might even want to forego the individual stage
>inputs

I've never used the Serge VC EG (5 stage as I recall), and didn't remember
that it had a single VC Slope input. I may have just stolen the idea from
them and forgotten.

>and just have the one "all" input. saves the minimal cost of 4 jacks but
>also
>saves a fair amount of panel space, especially if you opted for cv
>attenuators, too. that way you`d need : 5 jacks ( gate, trigger(?),vc all,
>+out,-out ) ; 5 pots (a,d,s,r,cv atten. ) ; eg ic; maybe 2 op amp ic`s
>like
>tlo84;an led; a few resistors and caps.

Well, like Larry said, the individual VC inputs are for "the masses" -- and
are cheap enough to justify. But there is not enough space to have a - OUT.
BTW, I think having the VC inputs disconnect the pots (so they can be used as
attenuators) is the wrong way to go with a VC EG. I find I want to get a good
envelope setting, then use some CV source to slightly alter it, so you kind
of need attenuators and initial level pots.

i haven`t built anything in years
>but
>could probably manage this based on its simplicity on a perf board. i`m
>way
>out of date so i don`t know what pots, etc. are running these days. i`ll
>stop
>by radio shack just to get a feel for prices.

The MOTM standard Spectrol pots run about $5.50 each I think, you can get
some carbon pots for around $0.80 each, but they have 30 degrees less
rotation, and are kind of nasty in general.

>secondly, as i`m even more mechanically inept than i am electronically
>inept,
>i`d be most interested in a drilled front panel. please let me know......
>thanks!

If there is some interest, I could drill some panels for several interested
parties if they were either pre-marked, or we had some common agreement as to
the hole pattern in the panel.


In a message dated 2/13/2000 12:33:15 AM, DAVEVOSH@... writes:

>and i was surprised to see that they didn`t have a "vc all" input !!!
>i was surprised as it is easy to do and an inexpensive addition. on the
>brand
>"D", there even looked to have been sufficient panel space for the additional
>pot/knob and jack. can`t believe they missed it although the "feature"
>is
>still there if you use a multiple to send the voltage to all the inputs
>simultaneously. kludgey but at least do-able.

This is because they don't have Barlow working for them! But I do think the
SUSTAIN level almost always needs to be handled separately from the slope
parameters, and I often want to handle some of those parameters in opposite
ways.

>did you say you had a s∗∗∗∗ tkb ? then the individual inputs might have
>some
>value to you if you used the 4 output voltages to control the 4 parameters
>giving you 16 selectable, preset envelope contours as one simple example.

Or any four bank sequencer or CV source. Good point!

JB