Dirtbag v3205 Output?

[jwpartain1]

Hey!

I've got a problem with my Dirtbag build: namely I have no delay out from pin 3 of IC4 or pin 3 IC5. I do have input to pin 7 of IC4, but no input to pin 7 of IC5. It seems as though the v3205's are nonfunctional, or at least IC4 is. Are the Cool Audio chips available at Small Bear pretty reliable in general?

Thanks,
Justin

[madbean]

Do you have output on pin4 of IC4? There are two outputs per IC.

Any noise on pins 2 or 6 of IC4? That is where the clock signal goes. If there is no clock noise on either pin, then the v3205s may not be the problem...it could be the clock.

[jwpartain1]

Ah I see. No, all I get is whine or no noise at all on any pin other than 7 of IC4. I'll check the clock circuit block, thanks for the speedy reply!

[jwpartain1]

Eh.. I find in my builds I only make the most obvious mistakes. The little V jumper on the board, I actually connected both sides of the V, not just one side as is required. Do you think I damaged the v3205's? I have corrected the error, but I still have no delay output from either. Also, the input to pin 7 of IC4 (signal input to the v3205's) is compressed and distorted relative to the signal I had there earlier, which was loud relative to the input signal before.

It may possibly be my power supply, as the supply I'm testing with now is a cheap Walmart supply. I'll test it with a different later this week and let you guys know.

[jwpartain1]

Well, I hooked up the circuit to a proper power supply and put an oscilloscope to a few points.

Anyways, the v3205's seem to be ignoring any input signal, yet outputs a sawtooth at whatever clock frequency (decided by the DELAY pot) you're sending to it is. In other words, if I set the DELAY pot to about half-way the v3205's both output a 25kHz sawtooth. The clock is sending a square-wave as expected, mind you.

So, I'm guessing the v3205's were damaged when I screwed up the V jumper. Attached are a couple of scope shots at various points.

The first is the input signal (300Hz) at pin 7 of IC4. The second is the output of IC4 at pin 3. And finally, the third is the output at pin 3  of IC5. Take note that even though IC4 and IC5 have different input signals, they are outputting basically the same thing.

Any ideas? Do y'all think I need to order some new one's? Thanks, guys/gals.

[jwpartain1]

I don't mean to bump an old thread, but I've replaced the v3205's with no luck. Just an update. Any thoughts are welcome.