I have a little bag of resistors, a few transistors and ICs which I unsoldered from an old tv when I first became interested in electronics. Today I measured the gain of a BC557 and a BC558 and I was happily surprised to read a gain of about 120 and 70, respectively.
Will these two trannies work (supposing they are not damaged somehow, of course) in a PNP fuzz face or rangemaster the same way as germaniums? (i.e. is low gain what most importantly distinguish a Ge transistor from a Si one?)
At the moment I can't test them in any audio circuit (I'm waiting for the parts to build a Si NPN fuzz face and a rangemaster, though, so I'll be able to test them in the latter), but I think some of you might answer my question.
Thank you.
Giulio
I would have thought that the most critical factor, was that a silicon transistor output overloads more suddenly than a germanium one. So that you would get a rounded over output, rather than a sharp square wave.
But it is all so subjective, everyone wants somethig different (which is why there is more than one amp, guitar etc design) that I suggest you make a FF with these & see. Let us all know how it goes.
I asked because I thought I had read somewhere that gain is what really matters in that circuit, but I might be wrong. However, testing is the most straightforward way approach to see the thing, except I have never played or heard (live) a Ge fuzz face, so I might only be able to compare it with the Si fuzz face I will build as soon as I get the parts...
If someone already did this kind of experiment, please, tell me your results!
Giulio
I'e built low and high gain FFs with Ge, Si and both. Although getting the gain of the transistors right is important, in my opinion there is still a fairly substantial difference between Ge and Si. Ge often sounds "dark" or "muddy", while Si often sounds "bright" and "light". My personal preference is to use lowish Hfe transistors when building Si fuzzfaces, especially for Q1 (I just finished one with Q1=65, Q2 = 200 and it sounds great). So I think your transistors are likely to make a good fuzzface. Just remember to adjust the collector resistor until there's between 4 and 5 volts on the collector of Q2. That's very important. You also may want to increase the collector resistor on Q1 to a value higher than that used on Ge fuzzfaces. I recently found that a 100k resistor "sweetened" a Si FF I was building.
Good luck.
You should read the technology of the fuzz face artical. If I remeber correctly the Ge transitors have a parasitic capitance between the base an emmiter (or collector or something) and that really affects the sound. I don't belive that the low gain Si's will give the same sound as Ge's but it might be a good sound anyway. For the cost of the four resistors (or whatever) it would be worth a try.
Thanks a lot guys, that's what I wanted to know. I'll build the pedal and, as I have no experience with fuzz faces, I'll just see if it sounds good or not!
Giulio