Parenthese Octave no effect and loud hum at full

[SweetBerryWine]

I'm stuck with the Parentheses build and am getting a major volume drop when I engage the Octave pedal and in the final 20% of turning the Octave pot CW, it makes a loud oscillating hum. The distortion, boost, and diode switching all work as they should. The Octave pot even makes the loud hum at full CW when the Octave pedal isn't engaged.

I know it's been asked a lot and I've gone through the suggestions people mentioned here of confirming matching D1/D2 diodes (I had 1N5817s and just swapped for BAT41s) and reflowing and confirming all components are correct values. I'm going to dig into it further tomorrow with my multimeter but am still new to the troubleshooting and knowing what to look for from the readings and schematic. Any suggestions on what could be the issue or what to look for?

 

[Locrian99]

I would first just reflow solder joints if you havent yet.

Here is the octave part.

I would audio probe it and see where the noise is introduced

 

[Nostradoomus]

what did you use for Q1?

 

[SweetBerryWine]

I used a 2N5457 for Q1
I just built an audio probe and am trying to test it now. Thanks for that info, Locrain99.

 

[SweetBerryWine]

Runs clean after C2. Hearing loud hum on pin 2 of Q1. I'll look into best part to swap it with.

 

[SweetBerryWine]

I just swapped Q1 with a J201. Same buzz... I thought for sure that would've been the culprit. I'll do some further digging...

 

[Nostradoomus]

Mind your pinouts! Did you get your jfets somewhere reputable?

 

[SweetBerryWine]

I got them from AionFX and triple checked on pinout but will quadruple check tonight.

 

[Nostradoomus]

Can we see the solder side as well?

 

[SweetBerryWine]

 

[Nostradoomus]

Is this bridged?

 

[SweetBerryWine]

So, I reflowed everything again, cleaned up that bridged solder joint (thanks Nostradoomus), replaced a couple pots. The boost works when standalone. When I turn on the distortion it's incredibly low volume but I can hear all the of the pots working and when the octave is engaged, I hear that now operating as it should. The issue now, why has the volume completely dropped out when distortion is engaged?? I was trying to make sense of the schematic to test with my multimeter but couldn't figure it out. Could someone provide some advice on where I should be looking and what voltages I should be seeing?

1 8.2
2 4.1
3 3.8
4 0
5 0
6 4.1
7 8.2
8 8.2

 

[neiltheseal]

You should get the voltages in the link below. Yours seem ok except for pin 8

https://www.madbeanpedals.com/projects/_folders/DistBoostOD/pdf/SlowLoris2020.pdf

 

[giovanni]

Are you 100% sure your resistor and caps values are all correct? I would check the ones in the distortion circuit to make sure they are. I would also visually inspect all solder joints, if you haven’t already, and reflow the ones that look questionable. Good luck!

 

[neiltheseal]

I think you have the wrong value in r21 at least.

Looks like a 470r not a 47r. Probably doesn’t matter but may be worth checking others

 

[neiltheseal]

And what do you have in q5?

This should be a jfet like q, but q1 and q5 look different in your pic.