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First you say "ive searched but i cant find anything" then you say"are there any better solutions than the old 3904 /6 transistor types" Is that nice?
He had a 2-cent spec ("mic pre out of a small number of parts ...just two or three transistors...") and I gave him a 2-cent answer. Throwing two (well-behaved) transistors together is chimp-work.
OK, that was too easy, so now he wants old-school sound, Ge transistors, low noise. I'm actually very shocked nobody has said "transformers" or "balanced input", or "Phantom power". To me, on-the-cheap, you just can't beat some of the <$99 mikes even if they do need phantom.
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what about germanium transistors used in old consoles.
They suck. They baffled me at the time. Most Ge amps were awful, only the best have escaped history's trash-bin. After I'd designed in Si a bit, I understood Ge: it is a lot like a bad Si transistor, Si is much easier to design with. BTW: early Ge transistors had Noise Figures in the audio band of 20dB and 30dB; you had to select them even for telephone amps. You didn't find transistors in consoles until NF got down near 4dB, and to actually get that took some very sharp pencils (no calculators!) and some tricks.
By 1970, Si transistors were "perfected". Seriously: you don't get a lot better than the good-old 3904, 4401, 2222 types, except in the most extreme problems. If you can't build it with a couple 2N2222, you probably can't be happy with LM394 or the THAT Corp arrays. Noise may be lower on the meter, not on the ear. Matching is better on the duals, but you need a pretty complicated circuit before you can balance the duals well enough to tell, and your grandma doesn't like that. Most noise is, in fact, not the fault of the transistors.
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few parts mic pre that sounded good with the old console sound.
Ah, that's not chimp-work design, that's a research project.
Here. This is not a BBC or RCA console amp, and it is so very "square" that nobody has danced with it in 35 years. But after pushing it around on paper, I like it better than the other plan, for 9V and few transistors.
Use any dang small transistors you like. For NPN, reverse all polarities. For
Beta over 300, change the 220K to 680K. Many modest Si power transistors will work too; Ge power transistors probably won't.
Maximum gain is almost 50dB. Maximum input level is 100mV: if you run hot levels, skip the first stage and drive the top of the pot directly.
With any Si transistor, or the latest quietest Ge, noise will be in the mike, not the amp.
And what about transformer, balanced input, or Phantom? For hot condensers, stick a 600:150 transformer in front and apply Phantom to the 600 ohm side any conventional way. For dynamics, wire it 150:600 for a slight increase of gain (but for dynamics inside bass drums or Fender amps, wire it 600:150). Transformerless input is not really a 2/3-transistor 9V problem.
