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Subject: RE: Dumb Power Supply Question?

From: "Tkacs, Ken" <Ken.Tkacs@...
Date: 1999-10-20

There are schematics sprinkled around the web that are at least sources for
thoughtful chin-rubbing. I pulled down the schematics for the Moog Modular
off someone's site at one point-I wouldn't bother building anything
significant out of it (Paul's 'modern' implementations blow them away, and
the kits cut way down on the DIY effort), but it shows the thought processes
for some things. And things like multiples, passive high-pass & low-pass
filters, mixers and so on are easy to tinker together (I use that word a lot
lately), a lot of them without even using circuit boards!

I also thumb through my old copies of Polyphony magazine (EM when it was for
DIYers) and there are ideas in those, too. You can even find old Paia 4700
schematics in there and on the web, which probably isn't worth much except
for things like the 4-channel mixer, etc. A lot of people talk about
"Electronotes" but I think the only way to get those is to pay Bernie
Hutchins (sp?) a big lump $um for back-issue photocopies.

When I get some "utility" modules built and tested, I'll throw some
schematics up on my site. But like I say, modules of real substance (VCOs,
VCFs, etc.) I'm going to get from MOTM and only hack together simple but
useful things myself.

Things like Gate Delays... my belief is that these are simply integrators
followed by Schmitt triggers, which is like a 2 op-amp solution. I have yet
to build one, but I think it's a helluva useful module to have around (like
the HADSR in my Korg MS-10... almost nobody implements that 'hold' feature,
but I used to use it all the time). Changing the times that gates and
therefore envelopes come & go is an important sound-shaping function.

But, you know... mixers, inverters, that sort of stuff you can find the
basics of in $10 books at, dare I say it, Radio Shack, too. Sometimes its
fun to thumb through non-music electronics circuits and just think, "hmm...
would something like this destroy a musical signal in a really rude way that
I can use...?" I'm always on the lookout for that kind of stuff. Cheapie
circuits to compliment the quality, rock-solid modules. "What if you take
the weird thing on this page and follow it a couple of diodes and then with
the weird little circuit on THAT page and put a feedback pot on it?" Who
knows, maybe there are some cool simple modules yet undiscovered. It's worth
playing with.

(The only significant-and it really is big-thing I've ever been tempted to
build out of the old Moog schemos was the Bode Frequency Shifter. But Jurgen
Haible is working on his own, which is interesting to follow. I don't know
if Paul would ever tackle an FS... it's a specialty module that seems to
require a hell of a lot of circuitry.)



-----Original Message-----
>The utility panels will be tinkery stuff like multiples,
inverters, logic
>gates, stuff like that.

Y'know, these are the kind of modules that I miss from the
MOTM, things
like trigger delays, gates, clock dividers, etc... where
would I look to build my own, if that's a possibility? Or
should I just buy more Doepfer (wink, wink, nudge, nudge)