ilovefuzz.com

braaandooon, the legend that he is, gave me an op amp big muff that had some issues. I just replaced a few of the capacitors (one was visibly chewy) but it had no effect on the sound. Basically it sounds like its a devi ever pedal or some shit. If you play quietly or roll back volume it won't event make any sounds, play hard and it will sort of sound liked a gated fuzz/od. Actually kind of kool, but not what I want out of a muff such as this muff.

Should I keep going through and replace every old capacitor? Also, the tone bypass has been, well, bypassed. There is also a strange bridge on the pcb, as if the original trace got fucked up so this is bridging it?

Ran out of patience/parts today and want to know if I should track down each cap and replace it, or could it maybe even be the op amp?

Here are some pictures:
https://www.dropbox.com/sh/tguf1azbk2fx ... wfAra?dl=0
Ordered a new multimeter off amazon, and have the rest of the capacitors coming in this week or early next week.

I ordered all the capacitors I don't have. Any chance it could not be a cap issue?

Voltages on the 4558 & 741 and pictures (yours aren't working).

I have a really shitty possibly non functional multimeter. What setting do I put it on to read voltage? It's on of the spin knob ones with tons of symbols

Will fix pics tonight

Put it on the 20V setting, black to the enclosure, red to probe about.

Fuck. This piece of shit multimeter just pots constantly changing random numbers on the screen, regardless of setting or whether probes are in. Fuck that. Never get an Excel XL830L

Are you in the US? I believe Harbor Freight (I think i'm thinking of the right place) should do a cheapy meter that'll do the job.

Random question... do you think you could weigh the pedal for me? Coincidentally trying to find out the shipping cost for one from a guy in the US to me

No scale, but I just checked and the large box big muffs are all shipped as 2lbs from amazon.

Odd that photos don't work -- they work for me. Maybe it's because I'm using dropbox

Here is the folder on DB with pictures:
https://www.dropbox.com/sh/tguf1azbk2fx ... wfAra?dl=0

Was checking out this page: http://www.geofex.com/fxdebug/bias_prob.htm

It sounds like for sure it is a biasing issue. Got the multimeter and will take a stab at it tonight. How do you fix a biasing issue? Does it imply cold solder joints or bad resistors?

Take voltages first, it'll confirm or deny that and then you work on how to fix it, if it is the issue.

4558 is 8.92
741 is 9.33

Need voltages for all 8 pins on each chip

Like so,

whoops!

741:
1: 8.79
2: 8.37
3: 8.97
4: 9.04
5: 0
6: 8.86
7: 9.39
8: 0

4558:
1: 8.90
2: 8.89
3: 9.25
4: 9.32
5: 8.89
6: 8.89
7: 8.92
8: 9.30