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I built this pedal a long time ago and it was great but haven't used it in a few years. Plugged it in today and it has A LOT of hiss. If I turn the level up much past 9-o'clock it swamps the signal. Turning up the trim pot also increases the hiss. Power jack and battery the same. I reseated the transistor leads in their sockets. Room temp is "cool".

Simple circuit, I'm assuming it's an OC76 transistor issue?

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Twisting and tinning is for chumps.

That seems most likely. Have you tried pulling the trannies out and reseating them in the sockets? Maybe juggling their positions around and seeing if that affects the output?

If you have a few PNP silicon BJT's (e.g. 2N3906) on hand, you could pop them in there and see how it sounds. The gain will be a lot higher, so it'll probably sound super-fuzzy, but you can see if the hiss is reduced. Just pay attention to the pinout vs. the OC76's if you do this.

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“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Yeah, I did try reseating the legs with no change.

The transistors I have left over from the OD-2 build are NPN, but I do have two spare 2N404s that I think are geranium PNP? Are those OK to try? Labeled 75 and 101 hFe.

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Twisting and tinning is for chumps.

Yep, for sure. Just check the pinout on those vs. the OC76 and install accordingly.

P.S. Geraniums look nice in your garden but sound lousy in a fuzz.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

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Twisting and tinning is for chumps.

Swapping in one of the 2N404s eliminated the hiss. I tried 4 or 5 different permutations of the 2N404s and OC76s with very different results. Ended up with the first OC76 pulled and replaced with a 2N404. A little tweek of the bias pot, voila! Waves of Fuzz!

Thanks Bob.

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Twisting and tinning is for chumps.

Yep, those NOS germaniums are finicky beasts. Easy to understand why the world went to silicon transistors....

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2