BYOC ESV Fuzz bias mod gone wrong-ish

[edson]

Hi,

I tried to mod my ESV fuzz to have an external bias. Did this by buying a 25K pot to replace the internal trimpot.

I tried with a 50 K pot first, just for fun and it was working fine, although very little range. So I changed it to a 25 K trimpot.

Now, something interesting happened, don't know if a solder point or cable touched something it shouldn't. And I saw a little spark...

Then later, it continued working, but there is a constant hum in addition to the nice fuzzyness.

Any idea what might have got wrong, or what I should check? How do I make it "quiet" again?

And when I solder a pot to the bias area, how much does it matter on which lug I connect the "right/left" connector from the bias point in the board to the pot?

/Edson

[Gus]

did you ask at buildyourownclone?

did you look at the stickys at this site?

[edson]

did you ask at buildyourownclone?

did you look at the stickys at this site?

Haven't gotten an answer at byoc yet, that is why I'm asking here. Just need some pointers, thought that someome might know "exactly" what to look for.

/edson

[R.G.]

Pretty much the best advice for mods gone wrong is to put it back the way it was and see if the modding damaged something so it *can't* work right. After that, the re-modding can begin with a stable base to work from.

Sparks in pedals are Bad Signs.

[LucifersTrip]

Any idea what might have got wrong, or what I should check?

you should compare the hum voltages to the voltages when it was working well...did you try jiggling the components gently while in hum mode?

And when I solder a pot to the bias area, how much does it matter on which lug I connect the "right/left" connector from the bias point in the board to the pot?

it shouldn't matter if your just changing the series resistance from Q2C to 9V+.  But, can't say 100% until you post a schematic and explain
exactly what you're doing.

[edson]

This is a little bit embarassing...

I think it was only a matter of using an isolated output.. and not 12 V. I was mistaken and used a 12V output on my Voodoo Lab 4x4 so it seems...   

I noticed it, cause I almost fried another pedal...

Anyway, I changed it to one of the isolated 9V outputs, and it seems to be working fine... I will test it more throughly when I can make more noise...

/Edson