Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  
previous: Alex Awright, this baby has been boxed u... -- 1/22/2003 7:43 PM View Thread

Re: Noise in Zombie Chorus

1/22/2003 9:08 PM
Mark HammerRe: Noise in Zombie Chorus
Layout is pretty important when dealing with anything where high-frequency clocks and audio have to coexist.  
It's perhaps a good idea to use shielded cable for connecting your pots, jacks, and other audio connections, and also a good idea to keep the clock away from the audio section. RG's layout has "quarantined the 4046 over to the far corner of theboard, but your own layout may not have done so.  
If audio grunge is still a big issue, consider upping the value of C2 to filter out a bit more high end. It is currently .001 (1nf). Hike it up to 1n5 or even 2n2 (.0022uf) for a little more noise reduction.  
The use of TL062's is important to the successful functioning of the device, however they are not the quietest op-amps in the world. You can sub other op-amps, but you'd probably need to use a trimpot to set the bias voltage and that's not part of the layout. Of course, having perfboarded it, you may have soem flexibility. Look at other MN3007-based flangers and choruses (like the BOSS ones) to see examples of how the bias voltage is provided on pin 3).

Alex Oddly enough, I get no noise when I... -- 1/22/2003 10:13 PM