NPN's Best Clipper?

[bobsamps]

I have been building distortion pedals for a long time. I was wondering what NPN transistor is best for clipping to get distortion or fuzz? I have been asked by another musician to build him one. Now I now everyones ears are different and I have substituted many for various reasons but does anyone have an idea of one type of npn that is preferred more? I was going to build something similar to the traditional old fuzz like in the 60's. Thanks for any replies.

[J M Fahey]

ANY .

All NPN small signal transistors are and sound the same.

The sound is in the project, how all parts are chosen, interconnected and interact, and not in parts themselves.

EDIT: so much so, that respected Elektor magazine stopper printing Transistor codes in their projects, because so many would work and they didn't want endless letters asking about replacements.

So most of their projects (unless specially needed, of course) labelled them as:
TUN : Transistor Universal NPN (silicon)
TUP : Transistor Universal PNP (silicon)
DUS : Diode Universal (Silicon)
DUG : Diode Universal (Germanium)

Check this page, print it, and staple to your Lab wall

TUP, TUN, DUS, DUG

Their examples are European, because ... well .... they are European, no doubt some friends here will write some small list of popular transistors and diodes available in USA, both American and Japanese.

[bobsamps]

Well I know this isn't true for pnp's. I'll check a few schematics to see what others have settled for. Thanks,

[Jazz P Bass]

Not that they are widely available, but Germanium transistors had there own little querks that made them amendable to fuzz & distortion circuits.

[J M Fahey]

Maybe by PNP you mean Germanium?

Well, in that case it's possible, they are obsolete, were very poor to begin with and since they have not been in production for decades, the best have been already used and by natural selection, only the unwanted remain.

But in Silicon (what I guess you refer to by NPN) it's a whole different World. (Thanks God) .

[bobsamps]

Yes I mean germanium. Ok so you don't have a preferred npn silicon transistor? I do have several pnp germaniums and I have experimented over the years with them. I have found a few on ebay and at hamfests that have proven to be less than satisfactory as the ones originally used in 60's devices.

[Mark Hammer]

You seem to have confused "best" with "best fit". The gain of any transistor stage, as well as how much voltage swing there will be in each direction, is set by the components around the transistor. It is not fixed and built into the transistor, any more than the speed of a vehicle is built into its engine. The potential to go faster certainly comes from the engine properties, but you can drive a Lamborghini at 10mph just as well as a 15 year-old Corolla, if you're only stepping on the accelerator gingerly.

And those components around the transistor are often set on the basis of the particular characteristics of the transistor, how to bias it, etc. One could achieve the exact same outcome with nearly any other transistor, if you were willing to put in the time to figure out what the values of the same adjunct components needed to be to achieve that outcome. The same way that you can drive 2 different-sized vehicle at the exact same speed by applying different amounts of gas pedal.

So when people say "I used such and such a transistor, and it sounded lousy/great", what they really mean is that, without changing anything else other than the transistor/s, the one/s they used was/were either a good fit to those components values, or a poor fit.

You will note that over different issues of the Big Muff Pi, not only were different transistors used, but the collector and emitter resistance values changed with them as well. Naïve folks believe that somehow the transistor choice made all the difference, and the additional components played no role in the behaviour of the transistors. WRONG!

[J M Fahey]

pnp germaniums and I have experimented over the years with them. I have found a few on ebay and at hamfests that have proven to be less than satisfactory as the ones originally used in 60's devices.

That's the point.
The best have already been used up (in fact in the old days manufacturers bought straight from the factory and got matched ones so a design with one worked very well with hundreds or thousand others from the same batch) and poor performers (lately even straight rejects) get tossed back in the pile.
No one gets tossed in the junk basket.
*Somebody* will buy them anyway.