New member and "stupid" question about Fuzz Face trannies

bigmufffuzzwizz · Post by **bigmufffuzzwizz** » 10 May 2011, 00:32

Yes that is what it needed!!! I'm so excited. I've been playing it for at least half an hour now!

I was getting oscillation at any guitar knob volume level but now its gone completely! I've only been able to try 2N3904's and 2N5088's. They both sound so good but I have a few more options available like BC108/9. I noticed that placed this 100pf on the first transistor pretty much cleaned up the noise. Adding the second one makes it super quiet!!! I'm thinking about experimenting and lowering the value of the first capacitor.
I actually built this for a buddy. I told him I found the silicon version and he told me thats what hendrix was using by the Band Of Gypsies era. I've been trying to find him the right pedal(he does have a very hendrix feel to his playing) and I think I landed on it. I was not a fan of Fuzz Faces previously but I think I'm sold now.
I also found the roger mayer mods on GEOfx site. Think I'll give that one a go as its just a few additions. I could probably add them on this board! I'm guessing R5 is the resistor that I would change out for for a fuzz pot? 1kb or a 2kb? A passive tone knob would be cool too but might drop the volume a little too much. Thanks for the help Simon!!!!

bass dread · Post by **bass dread** » 23 Dec 2011, 01:17

Thanks DrNomis, Great tip!

bass dread · Post by **bass dread** » 23 Dec 2011, 01:55

here is a layout of the tweak with the 100pf capacitors. I'm sure I read some where that raising the 330r up to 1k will boost volume so maybe its worth a try, its my first one so any feed back is appreciated, cheers

DrNomis · Post by **DrNomis** » 23 Dec 2011, 05:19

I recently posted some soundclips of my Ge Transistor Fuzz Face in the workbench section, if you're interested in hearing what it sounds like, click on the link below:

https://www.freestompboxes.org/viewtopic ... 10&t=15527

bass dread · Post by **bass dread** » 23 Dec 2011, 17:43

bass dread wrote:here is a layout of the tweak with the 100pf capacitors. I'm sure I read some where that raising the 330r up to 1k will boost volume so maybe its worth a try, its my first one so any feed back is appreciated, cheers

fuzzface without the hiss.gif

just noticed that c3 and c4 could go on row 1 making it slightly smaller

TV-Set · Post by **TV-Set** » 06 May 2012, 00:08

Hullo!

Been reading some topics here and there and it looks like I need to ask a few Qs.

First of all I'm almost a total noob and know very little in pedal building. So, I picked FF as my 1st project and kinda made a board which sounds like a real FF, much more than I could've expected from my 1st build.

I used the following schematic:

It is an NPN Si version (I didn't use the BC108/9 transistors though but tried different ones like BC239 or BC236). I also tried making some tweeks to it, like changing 330 resistor to 1k for higher output or putting a 10k trim pot in place of the 8k2 to adjust the Q2 collector voltage or adding a tone knob and stuff. all seems to work but I still have a big broblem that I do not know how to approach.

Just one word - SUSTAIN[/b]... the fuzz dies pretty fast, I mean to say that the distortion kinda clears completely, 3-4 sec after I hit a note the fuzz goes away (on the 1st 3 strings and high frets in particular, like 12 fret on e-high), although the sustain is pretty good on lower strings, especially the low E (10 seconds and up with gain at max).

I still wanna try different transistors, cuz what I learned so far is that it's them that make the sound (gonna try 2N3904, 2N5088... BC108/9 are not quiet so easy to find in my country).

So, any ideas? Any good sounding NPS Si transistors? What sould I look at to fix the sustain problem?[/i]

DrNomis · Post by **DrNomis** » 06 May 2012, 09:09

I've tried using two BC549C Si NPN Hi-Gain Low Noise transistors with Hfe's of 640, they seem to work okay, but the circuit tends to oscillate when the Fuzz pot is maxxed, to fix that, you can solder a 47-100pF ceramic cap across the B-C junction of each transistor, and,or solder a 27 Ohm from the 20uF cap's + terminal to the 1k Fuzz pot's wiper terminal...

The BC549C is the plastic-encapsulation equivalent of the BC109C....

TV-Set · Post by **TV-Set** » 06 May 2012, 16:35

Gonna try those Qs then.

But what about the SUSTAIN problem?

I've been reading lots and lots of articles on the web about FF-like circuits. Seems like its common design of 2 transistors suffers from fast note decay, and I really hate that. If there's anything I like more than fuzz, it's sustain.

DrNomis · Post by **DrNomis** » 07 May 2012, 00:41

One thing you could try is putting some kind of compressor between the guitar and the Fuzz Face, something like an MXR Dynacomp seems to work, then play around with the knobs on the compressor till you get the amount of sustain you're after, turning-up the output of the compressor should help things alot...

For what it's worth, my Fuzz Face pedals don't seem to have much sustain when you play above the 12th fret on the G,B, and High-E strings too....

TV-Set · Post by **TV-Set** » 07 May 2012, 14:23

DrNomis wrote:One thing you could try is putting some kind of compressor between the guitar and the Fuzz Face, something like an MXR Dynacomp seems to work, then play around with the knobs on the compressor till you get the amount of sustain you're after, turning-up the output of the compressor should help things alot...

For what it's worth, my Fuzz Face pedals don't seem to have much sustain when you play above the 12th fret on the G,B, and High-E strings too....

Thank you, man. It's that I don't own an FF so I couldn't run them side by side

So that's a reliefe. The compressor also helps, but that's secondary, it's just important to know that it's in the circuit... I mean, I tried building 4 other 2 transistor fuzzes (much similar to an FF circuit) and they all seem to have the same sustain "problem"

Also thx for your prev suggestion about C-to-B caps, those really smooth the fuzzies out real nice and take care of the high freq oscillation

Seiche · Post by **Seiche** » 09 May 2012, 08:04

how do you have Q1 and Q2 biased? maybe biasing them higher than the "golden" values will get some of that sustain back?

TV-Set · Post by **TV-Set** » 10 May 2012, 23:59

Seiche wrote:how do you have Q1 and Q2 biased? maybe biasing them higher than the "golden" values will get some of that sustain back?

Hi! At first I didn't even bother biasing anything. Then, when I put a 10k trimpot to Q2 collector I set the bias at 4.5V. The next day I read on the web that this type of circuit with Q2 biased that way might turn your bridge pickup into the neck pickup when playing on high frets (sound-wise that is), and infact that is another of my issues. The article I was reading said to try and bias Q2 to a higher or lower voltage. So I set it to 6.0V and kinda solved the whole pickup sound problem. Doesn't seem to have much effect on sustain though. Possibly it is highest at 4.5V and you start getting some crazy tones when you move away from that voltage... overall, the illusive sustain is still a mystery for me

PS: just a quick update (just feel like sharing

) you know you guys, I tried a pair of matched Si trans (Q1 83, Q2 123) and was not impressed.

not much gain for my tastes, so I think I'm gonna settle with some med-to-high gain transistors (Hfe 250-300). Then I'll try and make a demo of whatever comes out of it

Here's a layout I designed to work with a perfboard