Fuzz Face's resistors: 1/4w or 1/2w?

[FrankMBeat]

Hello everyone, I'm about to build a clone of Fuzz Face, similar to the original even in the components. After choosing the BC109 70's, Philips electrolytic capacitors, it is time of the resistors. I chose the ALLEN BRADLEY (found on Ebay). My doubt, between thermal noise and high fidelity of sound, what kind of resistors do I buy? 1 / 4w or 1 / 2w? Thanks to everyone for the advice.

[Marcos - Munky]

I believe there won't be any differences between 1/4 W and 1/2 W. Actually, for guitar pedals, you usually can go as low as 1/8 W with no problem. I'd go with 1/4 W because I have plenty of them. And I woudn't care on using good brand resistors, I believe I wouldn't be capable of hear any differences, so I'd just use the cheapest ones. But that's my opinion.

But if you're going for a "similar to the original even in the components", probably the 1/2 W is a better option for it's physical size. Actually, I'd look for 1W resistors, or maybe 2W. It's a good idea to message the seller and ask for the physical size of them before buying.

[FrankMBeat]

Thanks Marcos! Just another question: in a circuit, can i use 1/4w together 1/2w? or i must use one type of w resistor?

[pinkjimiphoton]

yeah bro, in a 9volt powered circuit, you can use 1/4 and 1/8th watt together, or 1/2 watt. i use whichever seems to fit the size requirements. i use 1/8th watt in a lot of stuff now. tonally, no difference at all i've found, 400 + some odd fuzzes later.

carbon comps are a lot noisier and seem to have more issues with values drifting due to temp and humidity.... a perfect way to make germanium more of a pain in the ass..
i understand why peeps use 'em,
but the metal film is tighter, quieter, and sounds better.

google up "brit face " mod in case ya need to compensate for temp sensitive q's...  i am on the wrong puter or i'd lay it on ya,

here's it from a google search

" Fuzzface Heat Protection

It's a reversed biased "Ge" diode just before Q1 to ground (or emitter).
The emitter and ground are the same thing.

This can help stop "thermal runaway" when your pedal gets a bit hot.

This stabilization is most necessary at the input transistor of the FF. At the output transistor, there's the 1k pot at the emitter (ground) that will help to stabilize variations in all three parameters. You should not note any difference in sound, unless you have a very leaky transistor or diode. It will only make any difference the next time you have to play that gig at some beach's Summer festival... If you only play in studios or in your bedroom, it's better not to make this mod, to avoid the risk of damaging your precious Ge transistor while you are soldering the diode!

To keep the Germanium tranny from "turning off" due to too much heat, the anode would be oriented toward ground in an NPN circuit. For PNP, the cathode would need to be oriented toward ground. I'm still not sure how or why this works, but it seems to. There's a writeup about it on Plate-to-Plate. About the only pedal that I can think of right off hand that has this feature is the TB MKIII.
As your circuit is PNP, you should put the diode with the line going to the emiter.

Reverse biased means that the cathode is more positive than the anode, so no current can flow (except the leakage)

[FrankMBeat]

Marcos thank you very much! You made me discover a world of new things, thank you!  Do you have any advice on a suitable type of Ge transistor? I have been recommended the AC125

[Marcos - Munky]

Well, actually the 2nd reply was Jimi's

I'd use Jimi's suggestions. This guy knows about fuzzes. If you want to add the diode for thermal stabilization but keep the board looking like the original one, you can put the diodes on the copper side .

For Ge transistors, are you going for NPN or PNP? But most important is to get them from a reliable source like Small Bear. It may be more expensive than other transistors from other sources you found around the internet, but are the others usable? How's the leakage and matching? Are they really germanium or are they counterfeit?

[FrankMBeat]

A friend of mine told me the same thing about PNP (my choise). I'm looking at SmallBear, they're expensive, but I guess their price is worth it. Difficult is to choose them ahahah

[Marcos - Munky]

I'd go with Small Bear. The price is higher than other places, but you'll get an legit and matched pair of ge transistors.

Since you're going for PNP, how exactly do you plan on powering the fuzz face? This may be an issue.

Btw, I built a PNP ge fuzz face some time ago. I used leaky transistors. To tell the truth, I didn't liked too much of that sound. Then, using the same board, I inverted the power and caps and used a pair of PN2369A. It's a NPN si transistor with low gain. I liked the sound of those ones more than the leaky ge transistors.

[FrankMBeat]

It's about experimenting, at the end ... I'm looking for a sound like this:

https://www.youtube.com/watch?v=3cLwIxzln4c


A classic with AC128 of which I found a kit here: http://store.synthrotek.com/DA_Fuzz_Face_Clone_Distortion_Kit (they assure you of the hand-controlled quality of the transistors)

But I must say that even the NKT275 Germanium is not bad!

[antonis]

Just an oversimplified tip:

Think of resistors wattage same as capacitors rated voltage.. 
(you an mix them as long as lower rating is high enough..)