How to Set Bias on Dunlop JDF2 Germanium Fuzz Face

[@ericskinner7355]

I have one of those early Dunlop versions of a Fuzz Face. It even has the Dallas Arbiter name in the "smile" It has never sounded right. I'll have to check this out. Thanks ✌️

[@pfg_pedals]

They’re honestly kinda terrible. The housing is the coolest part. I recommend at least swapping out the PCB for vintage style, and ideally gutting entirely. Especially with the early Arbiter branded Dunlop. The guts can be removed easily and reinstalled if for some reason you ever wanted to restore it to original. You can make it a really nice, authentic vintage replica, and they do look the part of the early FF. There are really nice OEM style parts available to make it slick.

[@poynt99]

You may have the transistors and associated pots mixed up: TP1 is for Q1, and TP2 is for Q2. Q1/TP1 are in the middle of the pcb, and Q2/TP2 are at the outside edge of the pcb by the two big 330uF caps. TP changes will affect the other Q's bias, which is perhaps what you are seeing. Slight correction: TP2 is actually the 100k feedback pot (which seems to be set to 0R in many cases) in series with the 56k feedback resistor. Interestingly, there is no collector bias pot for Q2.

[@blashuvec]

Will this work if the fuzz face had a 9v adaptor installed? It's still a JDF2 just w/o using a battery.

[@pfg_pedals]

Yes the bias process will be the same provided it was installed properly.

[@poynt99]

Just be careful and aware that this is a PNP-based fuzz, therefore you should only use a 9V supply that is isolated from your other 9V supplies.