REVV G3

[dfx_pedalpcbs]

Anyone make the REVV G3 using pedalpcb Tyrian?

You get a high pitch noise when the switch is in RED or BLUE mode.



C11, 13,14 and 27 are 100p

I changed them all out to 470p and this got rid of noise but it made the pedal a bit to bassy/muffled like a tone control turned down

Is the schematic wrong?

Thanks

[Elijah-Baley]

The G3 is really prone to squeal/whine.
I guess there's just a few of case where it squeals even if you are using a PCB. I know two stripboard vesion and both has this kind of issue (the G4 seems pretty ok). In the stripboard case there's just a few of case with no issue.

I didn't build it, but I would to do it, one day.
I don't know if the circuit is already into the box, but maybe this will solve the issue (honestly, I read this often, but I don't know if it really helps in this kind of case).
I advice you to use short wires for input and output, even better if shielded. To change the caps like you did can help, maybe you can find some value that doesn't change too much the treble response but tame a bit the squeal. Though this is a thing usually I don't like to do.
Probably the solution is a buffer (or a buffered pedal) in front of the G3. Nobody has never explain me why, but often this solve this kind of problem with high gain circuit.

[dfx_pedalpcbs]

Maybe I could try lowering either the input or output caps so less bass gets through

[willienillie]

SW1.1 doesn't seem to be doing much.

[dfx_pedalpcbs]

SW1 is the switch for the led

[niektb]

SW1.1 doesn't seem to be doing much.

I think it might be a ON-OFF-ON switch, in that case you can remove the 2n2 from the circuit in the middle position 

C11, 13,14 and 27 are 100p

Don't you think it's a bit much to change them áll to 470pF? I would gradually increment them (f.e. first 150pF and 220pF), starting with the C11.

The G3 is already quite mid-focused so reducing bass and treble further is not very beneficial for the tone I fear. Maybe you could reduce the gain slightly in one of the opamp stages?

You could also try increasing C3. Currently the cutoff frequency of C3 and R5 is around 160kHz, you can safely increase C3 to 470pF or maybe even 1n to reduce RF frequencies in the signal

[antonis]

Try to roll-off DC gain of IC1.1 & IC3.2 stages to unity by adding caps between R6 & V_REF and R34 & V_REF respectively..

[temol]

SW1 is not for the LED. SW1.1 works in conjunction with SW1.2. It's ON-OFF-ON type. So you have C7 with R15, then none and then C7 with R14.

[dfx_pedalpcbs]

Try to roll-off DC gain of IC1.1 & IC3.2 stages to unity by adding caps between R6 & V_REF and R34 & V_REF respectively..

ok what values would you recommend?

[antonis]

ok what values would you recommend?

Any value that forms a HPF of your taste..

say, 100nF for IC1.1 (32Hz) &  470nF for IC3.2 (34Hz)