Gain Pot (Knob) Does Nothing

[Mr. Strypes]

I decided to build the Virgil today. (Bad monkey! Bad!) Everything works fine other than the gain knob, which does nothing. What I have currently is a limited EQ pedal. Level, low, and high pots all work, but the gain does nothing. The sound is clear and clean.
I resoldered that section of the board to make sure there was good connection. The gain section still does nothing.
I also replaced IC2 with a new JRC4580. Same issue.
(I get the same results inside and outside the enclosure.)

Using a DMM, I checked the gain section of IC-2 (pins 1 and 2).

The resistance (unpowered) between pins 1 and 2 is 9k94

The voltage reading (powered) for:
Pin 1: 5.37 v
Pin 2: 5.32 v

I have no idea if those numbers are correct.

Side note: I noticed that the unit's power draw is 33 mA, which seems to be high.

 

[owlexifry]

swap the 4580 for something else like a 4558 and see what happens.

almost everyone that has built one of these with 4580 has had issues.

F

DEMO Post in thread 'Virgil Overdrive (Digitech Bad Monkey)'

Sep 30, 2023

Adding another report that 4580 led to zero change with the gain pot. Changing out to 4558 allowed the gain pot to do it's job. I tried with NE5532 which responded the same as 4580 - any changes in the gain knob were imperceptible. I just swapped everything over to 4558s, same as every other pedal. Tossed all the 4580s despite having a wide variety of lot codes, didn't work in virgil or pathos.

• falkry05

DEMO Thread 'Virgil Overdrive (Digitech Bad Monkey)'

May 10, 2023

So I guess I missed all the controversy as of late for this pedal involving JHS. I'm not exactly sure what the controversy was and too lazy to look into it too much (and really don't care.... )

But out of curiosity I built the pedal and tbh I think it sounds great!

You could say it's a YATS with a Bandaxall tone stack and wouldn't be too far off but the eq is pretty powerful and can pull some of the mids out.
It reminds me a bit of the Boss OD-1 (Oddity) but with more eq control and more bass. It can be pretty "big" sounding.

But I found that my favorite sound was with the...

• MichaelW
• Replies: 48
• Forum: Build Reports

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