Parentheses Mini - octave HORRENDOUSLY noisy.

[drew.spriggs]

Just finished a Parentheses Mini. Boxed up and although it sounds -good-, the octave side is just horrendously, horrendously noisy.

PCB was populated with quality components (Nichicon electro's, X7R ceramics, etc), and is built as per the schematic except for a matched pair of BAT41's for the octave section, and a 2N7000 for the boost (BS170 was DOA). All functions of the pedal work properly, just the octave function is absolutely unusable due to excessive noise.

Ideas?

 

[szukalski]

You flipped the 2N7000? Pinout on BS170 is DGS and the 2N7000 is SGD.

 

[drew.spriggs]

You flipped the 2N7000? Pinout on BS170 is DGS and the 2N7000 is SGD.

Yep, I've made dozens of pedals using that substitution and always flip it.

Every function works except for the octave being noisy

 

[drew.spriggs]

Actually, the more I play with this the stranger it gets.

For somebody who has built one of these, does it add octave CW or CCW on the knob?

 

[Diynot]

Should be adding CW

 

[drew.spriggs]

That's what I thought.

I had some board jank - I don't know if it was a manufacturing fault or I dicked something up while soldering, but the connection between Q3/Q4 was not going where it should be.

Cut some traces, ran jumpers from R16 and suddenly everything works perfectly.