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WIGGLING 'LITE' IN GUEST MODE

AM8040 Audity/E-mu Systems/Dave Rossum VCF
MUFF WIGGLER Forum Index -> AMSynths  
Author AM8040 Audity/E-mu Systems/Dave Rossum VCF
SmartBits
Last year I got my hands on a PCB for the AM2040 including an HM2040 Hearn-Morley clone of the rare SSM2040 chip. It took me some time to build this as I wanted to get my feet wet doing other (easier to build) DIY modules first. I haven't seen any pictures of this one in the wild so here is mine:







I replaced the TL071 for an OP177 and the TL072 with an OP2134 as per Rob's suggestion. The rest is according to the specs in the v2.2 project notes. There were some components missing on the BOM, might be useful for others who want to build this one:

Capacitors:
C2 100nF, 5mm.
C14 100nF, 5mm.
C17 10uF electrolytic, 2.5mm.
C18 2n2F, 5mm.
C21 100nF, 2.5mm.
C22 100nF, 2.5mm.
C23 100nF, 2.5mm. 5, C16?

Resistors:
10K: R12, R23, R28

The filter works fine and sounds great, nice and smooth. The only thing I still have to troubleshoot is the switch. When the module is powered up it is in 12 dB/Oct mode, I can then switch it to 24 db/Oct but not back anymore. So the flipflop flips but doesn't flop. Might be that the flipflop chip is defective or I made a mistake with the components around the switch. But it's no biggie as I like the 24 dB/Oct setting better... hihi
leeski
Wow looks good any sound samples of this great module applause seriously, i just don't get it
SmartBits
Thanks! I'll try to make a few samples soon(ish)...
leeski
SmartBits wrote:
Thanks! I'll try to make a few samples soon(ish)...


That would be very cool thumbs up
SmartBits
SmartBits wrote:
So the flipflop flips but doesn't flop. Might be that the flipflop chip is defective or I made a mistake with the components around the switch.


The Flip that didn't Flop... was just me not soldering a capacitor where it should be, I totally forget it and overlooked it when checking for errors (you can even see it on the picture...). I'm an idiot. d'oh!
But at least it works great now that I've soldered it! nanners
SmartBits
Here are some audio samples I made a while back. First file of each slope mode is just an envelope into the CV in. Second one is a bit of FM, can't remember exactly but I think it was the sine output of a TH-555 that modulates it. The 3rd sample of the 24 dB mode are a bit longer notes so the sweep can be heard a bit better.

The volume drops a bit sometimes, especially on the 6 dB mode, that happens when there's more resonance. I didn't process the files, this is just as the module sounds.
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