[sdiy] Circuit noise / oscillation

[Justin Owen]

-----Original Message-----
From: cs e [modulemania at gmail.com]
Subject: Re: [sdiy] Circuit noise / oscillation

> so, why don't you filter those high frequencies out with a simple fixed low-pass filter?

I started with a low-pass filter but I wasn't that happy with the results. Even though the frequencies I was trying to block out were way higher then the Q of the filter - I still felt like it was effecting the sound of the output.

Here's the solution I went with, pasted from my post of the 29th Jan:

"I set up a passive lag/slew circuit - the classic two reversed diodes, each into a resistor, both resistors into an anti-parallel capacitor with one leg to ground - signal out of the junction at the other leg.

Set it fast enough to let audio frequencies through unaffected but not so fast that the HF oscillations get through. 

This wiped out the problem entirely - but I still kept all the nice, rich, complex overtones I was getting from the feedback circuit."

Cheers,

J