Informant build. Buffered bypass wiring bleed

[Redredbettyz]

I recently built up and Informant. I wired it up with the according to the buffered bypass diagram. When I have the pedal bypassed I can hear a faint distortion in the background of the clean signal, as if the circuit's distorted signal is bleeding through. I'd love to keep it as a buffered bypass if I can fix the issue. Anyone have any ideas??

BTW experiment with clipping diodes. I settled on red LEDs, and it sounds great!

 

[Redredbettyz]

I double checked all the ground connections and everything seems to have continuity. I tried the additional wire and there was no difference in the background noise.

 

[Robert]

Really?... Now that's unusual... That wire grounds the clipping diodes in bypass so that really should quieten things down...

I'll dig mine out today and crank it up loud through headphones and see if I hear anything like that at all.

 

[Redredbettyz]

I used LEDs for the clipping diodes and they aren't lighting up when playing in bypass so the diodes seem to be grounding in bypass. When I lower the gain control in bypass, the background noise goes away. Does the same IC that is used for the buffer provide any op-amp distortion anywhere else in the circuit? Maybe that's where the issue is.

 

[Robert]

No. The buffer and input stages are in one opamp, the clipping and output stages are in the other.

 

[Robert]

Okay... I really don't like to do this sort of thing, but this should take care of your issue.

Make the connection shown here in yellow using a 1uF non-polarized capacitor (MLCC / Film).

You could use a wire, but the 1uF will reduce any popping when switching.

 

[Redredbettyz]

Awesome! The 1uF cap worked like a charm. Thanks for finding a solution for me!