I'm in Fuzz Heaven!

[RLBJR65]

I got a good Tripolett meter and what a differce a good meter makes!
I have not built RG's germanium tester yet but as soon as I get hold of a pesky 2.472K resistor (maybe a finely tuned trimmer instead) I'm gonna build it.

I was able however to match a couple of pairs of PNP germaniums close enough with my new meter, that sounded really sweet in the Fuzz Face:D

With Hendrix mod's
Q1 hfe 68, Q2 hfe 128 it's really awsome! Very smooth, flirting with feedback at 1/3 vol. and has gobs of sustain, yet cleans up very nicely by backing off the guitars vol.

With stock FF
Q1 hfe 70, Q2 hfe 146 seemes a little brighter and has more crunch, but a little less sustain.

They both sound great after buiding 1/2 a dozen Si. fuzz's I was never really happy with. I'm going to have to get busy and box them both up

Thank's everyone for everything I have learned here!!!

[Paul Marossy]

Yep, it's hard to beat a good sounding (correctly matched Ge transistors) Fuzz Face.  

[mojotron]

I got a good Tripolett meter and what a differce a good meter makes!
I have not built RG's germanium tester yet but as soon as I get hold of a pesky 2.472K resistor (maybe a finely tuned trimmer instead) I'm gonna build it.

I was able however to match a couple of pairs of PNP germaniums close enough with my new meter, that sounded really sweet in the Fuzz Face:D

With Hendrix mod's
Q1 hfe 68, Q2 hfe 128 it's really awsome! Very smooth, flirting with feedback at 1/3 vol. and has gobs of sustain, yet cleans up very nicely by backing off the guitars vol.

With stock FF
Q1 hfe 70, Q2 hfe 146 seemes a little brighter and has more crunch, but a little less sustain.

They both sound great after buiding 1/2 a dozen Si. fuzz's I was never really happy with. I'm going to have to get busy and box them both up

Thank's everyone for everything I have learned here!!!

Don't forget to try different output and input caps as well. Some like the tightness of the .01uf output cap w/100K vol pot, 500k pot if you want a little darker sound, or perhaps the loose feel of a .1uf output cap and a 100k pot.....

A bigger input cap will give you a fatter fuzz - that can be cool, but not really what I like. I like to fatten up the sound after it's distorted.... thus I changed output caps...

I really like the GGG boutique fuzz circuit. If you like a big sound at about 3/4 fuzz - try an hfe of 70 (Q1) and 160 (Q2) and use a .1uf for the output cap... It's like going from moving the sound with a snow-shovel to pushing it with a 2 ton snow plow. But, then again some like that tight crispy sound.... but I get that sound from an Si fuzz, a Ge fuzz just has too much character at about 1/2 to 7/8ths on the fuzz pot.

I bought a bunch of Ge transistors, some old some new (I HATE the noise of the NOS transistors). I guess I went through about 100-150 transistors before I found the right sound from the combo and the right gain/leakage characteristics. At first I went off of the same info as everyone else - assuming there was a magic transistor and it was really old and really rare - I have a bunch of those - but I found some that are still being produced that make the right kind of sound - this took a long time - but don't rule out the current production stuff. If you just want to build one, you can get some decent transitors from someone that pre sorts them - but get the from someone with a reputation and don't pay more than $10.

[Paul Marossy]

I'll second the Boutique Fuzz Face...  

[Rick]

I'll have to try that Boutique FF, but so far my hands down favorite for Germanium fuzz is the Tonebender MKII -lots of wild angry character with this. Give it a shot with your extra germ trannies. It is not as fussy to bias also. I've also tried the silicon hybrids and well ...just not the same animal.

[RLBJR65]

Thanks for the sugestions! I think I'm going to try that .01uf output cap w/100K volume pot mod. on the one with the stock values since it seems to lean that direction any way.

Boutique Fuzz looks very tempting, but first I've got a MKII board already etched. Picked up some surpluss transistors yesterday and can't wait to get back home this week to do some more testing and put it together.

[mojotron]

Thanks for the sugestions! I think I'm going to try that .01uf output cap w/100K volume pot mod. on the one with the stock values since it seems to lean that direction any way.

Boutique Fuzz looks very tempting, but first I've got a MKII board already etched. Picked up some surpluss transistors yesterday and can't wait to get back home this week to do some more testing and put it together.

In a Ge fuzz face, the transistors are everything - I'll also add a MKII to my build list and let you guys know how that works out. Smallbear will give you pretty good transistors  - I got super picky and I bet that fist fuzz face cost me about $300 to get just right. But, then again my goal was finding a way to make these from current production parts so I had a lot to investigate + I added a little capacitence here and there....

I had a ton of transistors for the Si fuzz face I was building too, but in the end I settled for 2n3904s - it amost didn't matter on the Si FF as long as the gain was higher on Q2... I just slapped it together and poof it worked just right.

[Paul Perry (Frostwave)]

I have not built RG's germanium tester yet but as soon as I get hold of a pesky 2.472K resistor (maybe a finely tuned trimmer instead) I'm gonna build it.

Here's a thought, a 2.7K in parallel with a 30K (both easy to obtain) gets you to 2.477K, within 0.2% of 2.472K (the resistors themselves will cause more error than that probably, being 5% or 1%).

[RLBJR65]

Here's a thought, a 2.7K in parallel with a 30K (both easy to obtain) gets you to 2.477K, within 0.2% of 2.472K (the resistors themselves will cause more error than that probably, being 5% or 1%).

Thanks, Paul I didn't think of that :oops: I picked up a precision 10 turn 5K pot. Figured that once I build the tester it should be easy to verify the setting anytime since without a transistor in the test socket one end will be open.

mojotron, I got a matched set, they sound great but have a terrible hiss Didn't use the recommended changes though so maybe that was the problem. I actually used some reclaimed from an old radio.

[mojotron]

mojotron, I got a matched set, they sound great but have a terrible hiss Didn't use the recommended changes though so maybe that was the problem. I actually used some reclaimed from an old radio.

These are my thoughts on noise... You could use metal film resistors (reduces some noise - maybe 20%) due to thermal noise (see note 1 below). Some call this pink noise because the noise relates to the signal strength and not the static current for the most part - and kind of adds character to the sound - I kind of like it on a Ge FF. The other noise can be reduced by 3 means - see #3 first:

1) use NTE parts (NTE102, NTE102A or NTE158) - this gets expensive because you have to buy at least 6 to get 2 really useful ones and each one has a different character. BUT, this is the solution I like the most - but it takes patients and a little cash - like I said - for what I spent on my first FF I could have bought a real one from the '60s, but that was not my objective..... The newer transistors are made from Ge that is more pure and doped using better processes. One of the main sources of noise is thermal transition noise as a set of transistors energize to (from) a higher Fermi level within the semiconductor (Ge..)... kind of like a super Mexican jumping bean - if you put a jumping bean on the stove (which is a horrible thought!!) it will jump (I was a sick child) ... An electron transitioning to a higher energy state is like a super jumping bean bouncing higher and higher as it gets more energy - but if it encounters non-uniformity in the conducting medium (Ge - Ge+ or Ge-) you get "thermal" noise.... This gets into the physics of conduction and the specific device (which in this case is a transistor), but to make a long story short - the new transistors do sound different (I think much better!!) , but they are a lot quieter with respect to thermal noise... Which does give them less "character", but the good ones have a wonderful smooth sound.

2) put a 20pf - 50pf cap across the base-collector of Q2 - this affects the sound though - so try 10pf and move up to 50pf to see what you can live with.. This takes out the high frequency noise - which has a very "white noise" sound - its just plain old noise - but that cap reduces the impulse (or softens the leading edge of the signal) of the signal coming out of that transistor - which on a FF is Q2... If the cap is small enough you will never know it's there, but at about 35pf I notice the cap more than I care to, but at like 20pf the cap is not that effective

3) And, what I would try first - if you built with a pot on one of the transistor's collector - I would adjust that and see if you can eliminate the noise... it could just be a biasing issue where you have a weird clipping thing going on... and this could cause noise as your noise to signal ratio could be low due to the loss of gain in a naturally noisy circuit. If you have a constant hiss I would try this first. But, my Fulltone '69 pedal has a nasty hiss and I never could tweak it out - that is most likely thermal noise from the crappy transistors Fulltone put in there....

4) Call it character and convince yourself and others that it's really cool ... Sounds crazy, but listen closely to old recordings with Ge FFs - I'm convinced that they were fairly noisy... I'm not one for vintage noise, but in a lot of cases that what you can get with vintage parts.

If you try everything and it didn't help, I'm guessing that you have really leaky transistors - which can be tested as per the "Technology of the FF" paper. In this case the tons of static leakage current is producing a constant level of thermal noise - there is not a way to fix that without replacing transistors starting with Q2.  

I hate noise as much as others hate tone sucking effects. My FFs are ultra quiet compared to others with vintage components, but even my FFs have a little noise. And this is because you generate a lot of gain and clipping from 2 transistors... it's a bit of a trade off...
Hope this helps...