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On Tue, May 20, 2008 at 11:04 PM, James Elliott <johans121@...> wrote:Scott, you wrote in the email below:
On Apr 1, 2008, at 3:41 PM, clickmrmike wrote:
"Does that make sense? I know it's confusing. If you want, I can start
building mine now too and take some pics.
It's a very cool module, though. I added all the things I wish my
original had."
That would be awesome if you could start building this thing. My board is stuffed and now I'm trying to figure out how to wire it to the panel.....
Also, you mentioned a 100k dual ganged pot, 531-pc16dc-100k, do you know of any 50k dual ganged pots? Ken mentioned in his new forum @ electro-music.com that 100k pots installed with 47k resistors and the 22k resistor will result in a log type response - and that in order to achieve a linear response one would have to use 100k resistors and a 47k resistor instead. Well.... I've already stuffed my board, and I've had extremely bad luck in the past unsoldering components on the CGS boards (my solder sucker lifts solder pads off CGS boards), so I would prefer to use the 50k resistors if you know of any, If not, I can live with it.
Thanks,
Jim
----- Original Message ----
From: Scott Deyo <contact@...>
To: ModularSynthPanels@yahoogroups.com
Sent: Tuesday, April 1, 2008 5:01:10 PM
Subject: Re: [ModularSynthPanels] Bridechamber CGS SubOsc
Hey Mike,
I haven't gotten to mine yet, but here's the plan:
Use dual 100k or dual 50k lin pots.
You'll need two CV Mixer PCBs.
The different divisions from the PCB go first to the pots. Use a
system, like "higher division goes to upper lugs of pot". All those
pots are attenuators.
Let's do an example Alt Group of pots. You'll have six of these groups.
The Alt Group A, A/2, A/4, A/8 is wired together via 47k resistors to
the bottom lug of that Alt Switch, so when you throw the switch up, you
will get this Alt Group (the upper group) of divisions.
Alt Group A/6, A/16, A/32, A/64 is wired the same way to the top lug of
the Alt Switch.
The middle lug of the switch goes to any pad on the mixer (there are
three mixers -- two external and one on the SubOsc PCB) at pin 2 of the
TL072 (past the summing resistors, which we used up on the panel.)
This is cool, because it allows up to switch between useful audio
divisions and control/ clock divisions for each channel, independently.
The inversion of each group on the external mixers is from pin 1 of the
TL072, via a 1k resistor, just like it's done on the mixer of the
SubOsc PCB.
Mixer one is just channel A.
Mixer two is just channel B.
Mixer three is the multiplications and such.
The Mix switches are easy -- For Mix A, just take the output of channel
A to the outside lug, and the middle lug to the summing node for the
Mixed channel Mixer. Do the same for the Mix B switch.
Those switches make the Mix Output more versatile. With both switches
off, you just get the multiplication on the Mix Out. But if you're
going for super-super tone hugeness of the universe, turn it all on! :
)
Does that make sense? I know it's confusing. If you want, I can start
building mine now too and take some pics.
It's a very cool module, though. I added all the things I wish my
original had.
> So Scott, exactly how have you wired your version of the CGS SubOsc?
> The panel is cool, but I don't completely grok the switched pot
> layout.
>
> Thanks,
> mrmike
>
>
>
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