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Issue with Fuzz recently bought

PostPosted: Mon Aug 13, 2018 4:18 pm
by repoman
I recently bought a Ghost Pepbox Fuzz from the Buy/Sell board and it has a problem, I'm wondering about what to do with it.
I got it, it worked okay, basically fuzz came through the pedal at 100% up on the gain, at anything like 95% and below, it would get spitty/intermittent, then like 85% and below, there was zero sound coming through. Put a fresh battery in and it sounded the same, I knew it was a spitty fuzz, but figured maybe the bias was a little off, turned the bias knob a tiny amount, and now the pedal doesn't work at all. Did I kill the transistors or something with that bias tweak?
Edit: tried turning the pedal up all the way and I can hear a very very faint (hardly audible) fuzz effect coming through at certain settings with the bias knob.

Re: Issue with Fuzz recently bought

PostPosted: Mon Aug 13, 2018 4:36 pm
by crochambeau
I'm about to hit the "walk face first into a spider's web" level of stupid question here. Someone hold my beer...

Have you tried nudging the bias control in the opposite direction?

Without looking at a schematic it's hard to spit-ball ideas. I doubt that crashing or flooding the bias has harmed anything (I could be wrong, but since this isn't a power section I could be right). Is the bias control a pot strapped across the power rails, or are there ranging resistors involved?

Can you grab a multi-meter and measure voltages?

Re: Issue with Fuzz recently bought

PostPosted: Mon Aug 13, 2018 5:00 pm
by repoman
Yeah, theres nothing really audible (except for that tiny, tiny amount in one small area) across the entire sweep of the bias trim pot.
I know nothing about circuits really so I couldn't tell you if the bias control is going across the power rails or anything like that. There is a PCB building guide here though: http://www.ghosteffects.co.uk/pdf/si_pe ... _guide.pdf

Ha, just reading it it says on the 3rd page: "Do NOT turn the bias control all the way up as you may fry the 2nd transistor, BE AWARE!" although the pedal stopped working immediately pretty much when I touched the bias pot- the arrow on the bias pot was pointing to about 6:30 on the dial, and I turned it to about the 6 o'clock position and it stopped working. The ends of the bias sweep go from about 8:30 to noonish.
I guess I can try swapping out the 2nd transistor!


Edit: I just swapped the 2nd transistor with a 2n2222 I had and now the pedal sounds AWESOME!! It only gets splatty down below noon on the gain knob and get all sorts of thick and freaky above that, sounds completely different! Super thicc and weird at 100% gain!

Re: Issue with Fuzz recently bought

PostPosted: Mon Aug 13, 2018 5:40 pm
by crochambeau
repoman wrote:Edit: I just swapped the 2nd transistor with a 2n2222 I had and now the pedal sounds AWESOME!! It only gets splatty down below noon on the gain knob and get all sorts of thick and freaky above that, sounds completely different! Super thicc and weird at 100% gain!


Yay! Sounds like a bum transistor all right.

Re: Issue with Fuzz recently bought

PostPosted: Tue Aug 14, 2018 2:49 pm
by Jero
Nice that you got it working!...Lame that they send those out with that issue, however.

Re: Issue with Fuzz recently bought

PostPosted: Tue Aug 14, 2018 3:09 pm
by BetterOffShred
I was thinking that having any sort of control that the customer can access that BBQs a transistor seems like a fairly poor design decision ;)

Re: Issue with Fuzz recently bought

PostPosted: Tue Aug 14, 2018 3:16 pm
by crochambeau
BetterOffShred wrote:I was thinking that having any sort of control that the customer can access that BBQs a transistor seems like a fairly poor design decision ;)


A ranging resistor will cost a couple pennies. That shit adds up, yo.

Re: Issue with Fuzz recently bought

PostPosted: Tue Aug 14, 2018 3:23 pm
by Jero
crochambeau wrote:
BetterOffShred wrote:I was thinking that having any sort of control that the customer can access that BBQs a transistor seems like a fairly poor design decision ;)


A ranging resistor will cost a couple pennies. That shit adds up, yo.

:lol: Cheaper than replacing transistors.

Maybe it's job security. They can get some extra scratch every time someone sends one in that's past warranty.
(totally kidding, Ian/Ghost)

Re: Issue with Fuzz recently bought

PostPosted: Tue Aug 14, 2018 3:31 pm
by BetterOffShred
Yeah man I'm not digging at the builder, my bad. I was just saying from my experiences if you put a handle on something, someone is going to turn it ;)

Building production pedals is such a thankless job. People think it's like buying a cheeseburger. Lots of quality behind the scenes people take for granted.

Re: Issue with Fuzz recently bought

PostPosted: Tue Aug 14, 2018 4:07 pm
by MechaGodzilla
BetterOffShred wrote:I was thinking that having any sort of control that the customer can access that BBQs a transistor seems like a fairly poor design decision ;)

Have to remember that he sold these as DIY PCBs so tinkerers would have the option to do that kind of thing themselves, prebuilt ones from Ian wouldn't need messing with by the user (unless you'd spec'd an external bias pot, then he'd probably have stuck limiters in there :idk: )