Noisey sharkfin (hum at pin 2 of IC3) - solved but you might not like it

[midwayfair]

I've got some hum appearing at pin 2 of IC3. It gets quieter when the envelope is "open," and gradually comes back in as the envelope settles; it's also a little louder as the

It's perhaps 1/3 as loud as the guitar signal, so ... kind of obnoxious. I'm not sure if it's just the CA3080s or what; I expect them to be noisy.

It also gets quieter when I move my input guitar cable or reposition the pedal. That's weird. :/

The circuit works just as it should otherwise.

Anyone think a daughter board for a 13700 conversion would be quieter?

[peAk]

Jon, I don't have an answer to your question but I do have a question for you about the Sharkfin.

Is your sample and hold section volume quite a bit lower than your bypass? If so, did you, or do you know of anything that will fix this?

I know Cortexturizer did a clean/mix mod but I would rather just have the section louder.

[midwayfair]

Jon, I don't have an answer to your question but I do have a question for you about the Sharkfin.

Is your sample and hold section volume quite a bit lower than your bypass? If so, did you, or do you know of anything that will fix this?

I know Cortexturizer did a clean/mix mod but I would rather just have the section louder.

The total effect is a little tiny bit above unity when the envelope is open, and naturally is going to sound a little quieter when the envelope is closed (no treble). The sample and hold is essentially a square wave flipping back and forth between the envelope's open state and closed state. It's going to sound quieter for the same reason a tremolo might sound quieter.

[midwayfair]

Well, a 13700 solved it ... bit of a pain and it looks kind of ugly, but it sounds really good.

That chip was a little quieter, so I also jumpered R2 and then reduced R4 to 47K to bring it a little above unity.

[peAk]

Jon, I don't have an answer to your question but I do have a question for you about the Sharkfin.

Is your sample and hold section volume quite a bit lower than your bypass? If so, did you, or do you know of anything that will fix this?

I know Cortexturizer did a clean/mix mod but I would rather just have the section louder.

Mine just seemed lower than it should but you are probably right.

The total effect is a little tiny bit above unity when the envelope is open, and naturally is going to sound a little quieter when the envelope is closed (no treble). The sample and hold is essentially a square wave flipping back and forth between the envelope's open state and closed state. It's going to sound quieter for the same reason a tremolo might sound quieter.