Fuzz Face SI Transitor advice please

[Flying]

I spent the weekend, reading many threads on multiple forums and doing general fuzz face research to the extent that on Sunday night I decided I should just drop the whole idea, the issue is that I just could not work out which transistors I should be looking for, once I developed a short list I would go searching for them only to discover they were not available or from an unknown source and potentially rebadged, or I need to buy at least 100 to sort through to find the 2 that will create the magic! I looked at matched sets from SmallBear, but living in the UK if I can find something a little closer to home would be preferable.

I've decided my first foray into the Fuzz Face world would be a silicon Fuzz Face with NPN transistors, I'm looking for something that's probably on the smoother side of the fuzz spectrum, and it's the cleaning up with the guitar volume pot I'm keen to experiment with having heard some really nice tones some players get.

So if anyone could name some transistors I should try that are readily available I would be most grateful. My multi meter can measure hfe, but it's no Fluke, so probably a bit of a crude measurement, but hopefully good enough.

By the way, I'd love to trying germanium transistors, but I get the feeling that's a true minefield! How is it that such a simple circuit is causing me such a head ache?

Sorry for the ramble, but any advice would be wonderful.

[somnif]

Socket the transistors, and start out cheap. If a 2n3904 will work for 0.10$, go with it!

Can also try BC108C (the nominal "mojo" choice for silicon FFs), BC109C, BC209, BC239, etc etc etc.

Though honestly if you're looking for a tame, easy to control fuzz, the Fuzz Face isn't really where you'd want to start. It's fairly gnarly through most of its knob settings (but that's true of most early fuzzes really)

As always, "best" is what sound's good to you. The whole "minefield" issue is because the circuit is so simple, each component has more of an effect on the overall sound, couple with the fairly crappy build tolerances and state-of-the-art of semiconductor manufacturing in the 60s. Stop worrying about what the cork sniffers tell you "should" be in there, and just start throwing stuff at the circuit till you find something you personally enjoy.

[LaceSensor]

I made a fuzz face with BC108b metal cans, which sounded really fabulous. Very smooth. cleaned up great.
If I recall correctly, I biased it "under" which is an Eric Johnson thing (around 3v I think, rather than 4.5v) on Q2

I didnt select the transistors or anything by the way....

You can tune it by ear if you include a bias trim.

[Flying]

Thank you somnif & LaceSensor,

So far all my builds have been from well know verified schematics mostly using opamps, which I copy into my computer and designing a PCB layout for, I was trying to approach the Fuzz Face with a similar mind set, but I think the first thing I need to do is buy a breadboard and a load of different transistors and start playing, thankfully it's a simple circuit so I shouldn't get too lost in a load of wires!

I am intending to put a bias trim pot in, and I think I'll also experiment with small value capacitors between the Base and Collector of Q2 if it seems a tad harsh, I guess this is all the stuff that will be so much easier play around with on a breadboard.

Thank you both again for you advice and help.

[LaceSensor]

Thank you somnif & LaceSensor,

So far all my builds have been from well know verified schematics mostly using opamps, which I copy into my computer and designing a PCB layout for, I was trying to approach the Fuzz Face with a similar mind set, but I think the first thing I need to do is buy a breadboard and a load of different transistors and start playing, thankfully it's a simple circuit so I shouldn't get too lost in a load of wires!

I am intending to put a bias trim pot in, and I think I'll also experiment with small value capacitors between the Base and Collector of Q2 if it seems a tad harsh, I guess this is all the stuff that will be so much easier play around with on a breadboard.

Thank you both again for you advice and help.

For a fuzz face why re-invent the wheel? Vero or many reliable small, cheap PCBs out there

example

[somnif]

....this has made me want to experiment with SMD silicon in a Fuzz Face. I've not played in those waters much yet.

Hrm, can I really get enough mojo out of such mojo-less parts? 

[bsoncini]

You should definately get a breadboard for this. It is so easy to put together. Try playing around with the input cap. Lowering the value changes the sound a lot. Lower values will give you a more overdrive/distortion kinda tone. Higher ones a wooly fuzz tone. Can put a switch between the 2 or even a pot.

Also if you don't have one already. Get one of the cheap Chinese transistor testers if your multimeter can't do it. That way you can figure out what you like or don't like with the actually values of the transistors more than whatever part number is written on it. Transistors with the same part number can have really different values.

[somnif]

Also, one additional note, the Fuzz Faces (like most fuzzes of its era) are NOTORIOUSLY picky about what's going on around them.

Some sound great with single coils then get all grumpy if you plug in a humbucker.

Some only behave if you run your amp at full volume.

Some only sound good running into a Marshall. Others, only Fenders. Yet more, only Vox.

And gods help ye if you try to put anything with a buffer in front of one.

In other words: experimentation! Play around with the circuit, see what works with your rig under your working conditions. See how it plays with pedals in front and behind it. Poke it with a stick. Wave a chicken at it. Chant occasionally. Offer the circuit a drink. Whatever it takes.

[pickdropper]

....this has made me want to experiment with SMD silicon in a Fuzz Face. I've not played in those waters much yet.

Hrm, can I really get enough mojo out of such mojo-less parts? 

For the FFX fundraiser, my contribution was an SMT board with a Si Fuzz Face and Si Tonebender on it.  We probably still have a few boards kicking around somewhere.

[somnif]

For the FFX fundraiser, my contribution was an SMT board with a Si Fuzz Face and Si Tonebender on it.  We probably still have a few boards kicking around somewhere.

I looked it up (love the name). I'm always a little surprised at how pricey some SMD parts are, the 47uF caps are 2$ a piece! (Or, rather, their Murata equivalent since it seems TDK doesn't make em anymore)

[pickdropper]

For the FFX fundraiser, my contribution was an SMT board with a Si Fuzz Face and Si Tonebender on it.  We probably still have a few boards kicking around somewhere.

I looked it up (love the name). I'm always a little surprised at how pricey some SMD parts are, the 47uF caps are 2$ a piece! (Or, rather, their Murata equivalent since it seems TDK doesn't make em anymore)

Yeah, high density SMT Tantalum caps aren't cheap at all.

[pedalman]

You live in UK?  Jump on thomann and grab one of those t.c. electronic honey pots. Thomann has them for twenty-something bucks.

[Flying]

Breadboard and parts have arrived today, and I've been playing around and currently have the 'Axis Face' from Fuzzcentral wired up using a 2N2369A in Q1 and a DB139 in Q2.

It works and I've biased Q2 collector to 4.5V the hfe for the 2N2369A is 100 and 125 for the DB139.

I've had a play with a Big Muff before but this is my first opportunity to play with a fuzz face style circuit and there are a couple of things that I'd just like to know if that's normal for a fuzz face or if I need to tweak something/got something wrong.

If I play a note and let it decay the fuzz is there and sustains for a while then sort of dies off quick like it's gone down a step, the underlying note is still audible, but the major fuzziness has gone.

And my tone pots seem ineffective on my strat which surprised me, as too did the quick sweep from 10-9 on the volume pot before it becomes more gradual, but it does clean up nicely with the volume pot.

Over the weekend I'll redo the bread board with a straight forward fuzz face circuit, I did the axis as it was the last schematic I looked at, but I somehow suspect I may end up with more than just one fuzz!

[somnif]

If I play a note and let it decay the fuzz is there and sustains for a while then sort of dies off quick like it's gone down a step, the underlying note is still audible, but the major fuzziness has gone.

Listening to demos on youtube, this seems to be a feature of the circuit.

[jjjimi84]

I am by no means a fuzz face expert but would like to share my experience with you. When I was young I bought the Roger Mayer Axis Fuzz and tried using it with my fender twin and marshall jcm 800, at reasonable volumes it sounded okay through the marshall and dogshit through the fender. The same kind of fizzled notes and all around sound you described. I kept the pedal because its a roger mayer and i liked the enclosure.

Then I needed money and sold the amps and was selling pedals, right before shipping out the roger mayer i plugged it into a cranked billm modified blues junior and found the magic of a fuzz face. In my experience they need an amp wound up and will help give it more drive and sustain with your guitar volume playing an active role in the circuit.

I have since built too many fuzzes and bought even more to find they are finicky and temperamental. Some work great with this amp, on this day, with the moon shining and the tides recessed. I think that is the allure to them.

Ihave also built the axisface from fuzzcentral as well and remember there was a great range of tones on a strat from 4-9 and then the huge wall of low end fuzz on ten.

Not sure if any of that helps but welcome to the world of fuzz, it is costly and frustrating and ultimately one of the most fun sounds to play with.