MichaelW
Well-known member
So you flipped backwards from the board silkscreen?
DEMO Virgil Overdrive (Digitech Bad Monkey)
- Thread starter MichaelW
- Start date
This post contains an audio or video demo
Yes. It makes it like it wasn’t even installed.
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.
southpaw-dd
Active member
Glad I found this thread! I'm having the same issue with the gain knob not changing the signal (looks like unity gain through the op-amp on o-scope). Changing to 4558 did not help my situation - both sets of op-amps purchased through Mouser. Any other ideas?
MichaelW
Well-known member
Did you try the 4558 on both IC positions?
southpaw-dd
Active member
Hey @MichaelW - yes, tried that and didn't have any luck. I may have a different issue because I found a bad WIMA film 220n cap in that part of the circuit and replaced it, then the signal looked much better, but resulted with the 'unity gain' issue using both 4580s and 4558s (in both IC spots). I'm wondering if the 220p op-amp cap needs to be replaced, too. All of the resistors were checked and they are good.
