Lots of noise from Green Ringer type circuit

[soggybag]

I built a Parentheses Fuzz it's a Rat and a Green Ringer in the same box.

Here's a link to the schematic: https://www.pedalpcb.com/docs/Parentheses.pdf

The circuit works well but I get a wind tunnel like noise from the octave section when it's on.

The octave section feeds the Rat section through a pot that mixes it with the input buffer. Obviously the Rat is amplifying all the noise from the Ringer. Is there anything I can do To lower the noise out of the Ringer?

The Rat section is very quiet without the octave so I'm assuming all of the noise is coming from the octave circuit.

[MikeA]

Some questions about when it happens that might aid trouble shooting - do you hear it:
- With the input terminated but no signal coming in?  Or just when there's a signal? (in other words, it is noise or modulation)
- With the octave blend fully toward clean? (is it the input buffer)
- With the octave blend fully toward octave? (is it the octave section)
- With the Rat clean? (Gain all the way down, clip-to-ground switched off)

Looks like the Ge diodes D1/D2 had some confusion in the board silkscreen, are they the right way around?  Cathodes (not necessarily stripes) toward the base of Q4?

[soggybag]

Good questions.

- I hear the noise with or without anything plugged into the input. Only when the octave circuit is engaged
- the input buffer goes to the octave and both go through a blend pot into the Rat circuit.
- The noise appears as you blend the octave sound.
- the rat circuit is pretty quiet

The noise definitely seems to come from the octave. You hear come in as you turn the octave up and it s gone when the octave is not engaged.

I built a couple of these. One of them is very quiet. I used a pair of Ge diodes off the phase splitter. In the noise version I used Bat 41 diodes if I recall. They are blue with a black stripe. I didn't match the diodes.

[MikeA]

Thanks!  So idle noise in the octave ckt.  If you can audio probe it, I would terminate the input with a 1k resistor tip to ground, no input signal, then listen to the octave circuit @ Octave pot lug 3, then base of Q4, then base of Q3.  I would suspect one of  Q2, Q3 or Q4 is faulty and producing hiss.  If you can't audio probe it, I'd replace Q2, Q3, Q4 one at a time with known good parts.   Mismatched D1/D2 wouldn't give you noise without a signal, but the octave might be less than optimal. BAT41 have a Vf that's reasonably close to Ge diodes.