Synth-DIY Yahoo! Groups Archives

Thread

CGS29 Wave Multiplier Noisy Pots

2014-04-27 by oojimentis

Hi,

I have an older version of this module and it's never really sounded right. All of the pots make crackling noises and pops when turned, making the module not very useful. I don't think it's a batch of bad pots as it still makes noise when controlled from a LFO when the modulation level is adjusted.

The module does seem to make the right sounds, though it does not sound as good as other people have described theirs.

Any ideas of what to check would be most welcome. (I'm no electronics expert!)

Thanks,

Trevor.

Re: CGS29 Wave Multiplier Noisy Pots

2014-04-27 by cg_synth

Something is certainly wrong. The pots themselves are not used in such a way that crackles and pops would be expected. You probably have a construction error somewhere that is allowing too much gain at one stage, causing it to clip. Make sure the diodes and 470R around pins 6-7 of IC6 (last TL074 multiplier stage) are correct, as they limit the gain.

Re: CGS29 Wave Multiplier Noisy Pots

2014-04-28 by oojimentis

Thanks for swift reply.

(I have the old version of the board) I checked out all the diodes and they appear to be ok and double checked the 470R and 4k7 resistors around IC5B - those are correct too (I was hoping that I got them mixed up ;-) )

You've certainly given me an idea of what could be wrong and that's a great help. Any other suggestions would also be appreciated.

Thanks for your time on this,

Regards,

Trevor

Cgs synth

CGS29 Wave Multiplier Noisy Pots

CGS29 Wave Multiplier Noisy Pots

Re: CGS29 Wave Multiplier Noisy Pots

Re: CGS29 Wave Multiplier Noisy Pots

Move to quarantaine