What's the best transistor to for an NPN silicon Fuzzface?

[Chris Goodson]

I'm working on modding a wah to have a Fuzzface built in for a buddy of mine and I figured the PNP version might not be a good idea.
Small Bear doesn't have any NPN Ge's for sale so I thought I'd just go with a Si version.

[sir_modulus]

Well, IMO (if you use the ruffongroove version: Multiface) then use one Q as 2N5088 and the other as 2N3904. Or mix in some NPN Ge's if you can find some. A good bet is to get some 5088 and a pack of "NPN type switching transistors" from Radio Shack, or go the FET route. Use the ones recommened in the multiface. Thats my opinion.

Lm 250+

[petemoore]

I believe the NTE 103 is NPN Ge...better check tho.
 If you sockets Miss Piggy, you can control gain of the Q's, or use standard FF circuit by pulling a few parts from the sockets.

[RDV]

Almost any of them will work. I've had good results with a lower gain one for Q1(I used2N4401) and a higher gain one for Q2(I used 2N5089). Using a lower gain for Q1 prevents those nasty oscillations @ max gain. Using the higher gain for Q2 allows for a good strong output. It's also a good idea to use a 10k trimpot for Q2's collector resistor to set it to 4.5v to 5.5v.

Good Luck

RDV

[phillip]

BC108, BC109, BC109C, BC183, BC183L, BC209C.

Those are some of the ones that the original Si. Fuzz Face used...all of them except the BC209C are still in production, too

Watch out, the BC183 & BC183L have different pinouts than all the others.

Phillip

[petemoore]

I dug some super cool lookin NPN switchers [hfe 140-230~], with the big tin top hats, they work just fine, one to the next, not wayy different or somewhere in the basic NPN variety sound.    
 The FF test board can be put in a box, but I prefer having it on a shelf, then when I get the notion for FF'ing...a board like this can get a very wide range of tones/gain etc.
 It has everything  socketted or trimpotted, except maybe the Q1 resistor and the 'three digit'/ohm resistor [470?]...I start large and can bring it down by tagging a parralel R to it, use sockets for all Q's and caps, since theres not that many parts to yer not so basic Miss Piggy FF
 Yaff, with the small R under Q1> Emitter to ground, is another variable for Si FF.
 I just use a larger than necessary gain pot, [again a parallel R can adjust the range here, across the outside lugs], and socket that cap.
 By reversing the power and gain cap polarity [using nonpolar caps for DC blocking at input and output...the Circuit can quickly go from NPN to PNP use.
 Next time I'll put an extra socket in from the transistors collector to ground and it's base, using a 3 pin socket, getting into really high gain, it's nice to be able to tune the 'oscillation reducing caps that can go here, also at input or output.
 For My FF to really work right...so I can floor the Guitar volume and have the 'correct' input gain, input gain reduction is a good one...that would be the input gain mod for EZ face, but found values for your SC's and HB pickups with the input gain pot could be changed to  fixed values on a switch or in a socket.

[Nasse]

:shock: I want to thank Jack Orman of the YAFF project article at AMZfx, ordered some components from local supplier and they had those transistors suggested so I ordered few dont remember how many but maybe ten or few less and measured and picked them with my cheapo multimeter with hFe function and yes, it sounded like very good fuzzface

But tried some other trannies I had in my junk box (I looked after suitable hfe value in catalogs and books I had and datasheets online) and took some measurements and I believe it is more important to choose just right hfe transistors and bias them well than "what type" the trannies are, and it is nice with silicon trannies you can just use ordinary multimeter and dont need any special arrangement as with ge (which is quite easy anyhow)

I was so happy I decided I must post some small gift or funny postcard to Jack Orman, Aron Nelson and R.G. but of course I did not, maybe some day...

[ErikMiller]

I prefer the BC109C, but I have also had good luck with NTE123A's.

[petemoore]

I forgot to mention the BC's, they sound quite a bit different than the usual Si Suspects I think, I like the sound.
 The GEO Article "technology of the Fuzz Face" has a very good explanation of FF transistors. Finding a low gainer for Q1 helps the definition of the sound.
 How many ways can one person wire a FF?...I'll never know, I lost count of how many ways I've tried ...A Long LONG time ago...

[brett]

Hi.  My experiments support what Pete and others said - it is quite important to have a hFE of 60 to 90 for Q1.  The hFE of Q1 sets the input impedance.  Too low and you'll lose your highs and it'll sound lifeless, and too high and it'll sound thin and cheap.  One option for getting nice low hFE is to sort through power devices like BD139s or MJE3055s.  Otherwise, the Miss Flexible has a neat circuit that lets you choose the hFE of Q1 and Q2 from common NPN transistors.

have fun

[zenpeace69]

I have a Monsterpiece Fuzz pedal that a DIY'er made and it sounds pretty good with these NPN BC108 silicon transistors.  It isn't as high gain as my Aramat Mojofuzz (which has Ge Transistors), but it still sounds pretty darn good.  Not so responsive to the volume knob of your guitar as the germanium one, but still great sounding when pinned all the way.

[Hal]

as you can see, most people here have different opionions.  You should probably socket both the transistor slots, and play around, until you find something you like. Look at the Multi-Face page...as you can see, you can use any combination of hi-gain, lo-gain, MOSFETS, JFETS, etc...

I actually just started putting a "multi-face" on breadboard tonight.  I especially like the sound of a darlington as q1 and a 2n7000 as q1.  Crazy gain, and some cool hiss at the top.  I dunno, its crappy, but cool :-D