Germanium MM/MC Head Amp

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Some of us actually want a transparent amp that doesn't pollute the signal with "warmth" or any other woolly adjective! Uncorrupted signals please. The idea of using low performance Ge transistors is unappealing except perhaps from a retro perspective - sure its a design challenge, but its not going to be the best way...

Unfortunately - very often this is written by people who have never heard the sound of germanium amplifiers . And they never made amplifiers on germanium transistors .
 
Some of us actually want a transparent amp that doesn't pollute the signal with "warmth" or any other woolly adjective! Uncorrupted signals please. The idea of using low performance Ge transistors is unappealing except perhaps from a retro perspective - sure its a design challenge, but its not going to be the best way...



The original comment about low noise of the AF379 completely ignores the flicker-noise knee frequency - 600MHz capable RF transistors' noise specs seldom give this, and typically noise increases with decreasing frequency, sometimes dramatically, you cannot infer audio noise performance from RF noise performance - you'd have to measure it rather than extrapolate from 100MHz data.
About AF379 LF noise, is entirely true that one needs to test it first... I remember using AF239 in some project and having more noise than eg. a 2SB486. The 2SB486 are made for low noise audio, not RF (of course... is a slow alloy junction transistor). And fortunately the cause are not RF oscillations; the AF don't oscillated in RF (sometimes RF oscillations are the noise culprit)
The russian P27 are made for LF applications in mind also.
I'm thinking in purchasing some and build a pre like one show by Jenyok post #6, figure 5, but with cascode on second stage.

About using those parts in "2019" project... Let's see some:
1 - I love to experiment with challenging technologies far from mainstream. Silicon is boring to have good noise/HD results. I want to have it with Ge or tubes.
2 - Is fun, only for fun.
3 - some people have old cars, old houses; I have old electronic circuits.
4 - Not to mention the sound... sometimes a not so perfect project bring a good sonic result, as crazy as it seen from pure technical standpoint.
 
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Unfortunately - very often this is written by people who have never heard the sound of germanium amplifiers . And they never made amplifiers on germanium transistors .
Why on earth would I want to listen to the sound of the amp? The signal coming out should be the signal going in, uncorrupted but larger in power/volume, whether its jazz, punk, pneumatic drills, speech, aoelian harp or bagpipes.
 
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Well, when I was young I heard the "sound" of GFT32, OC811, AC122, OC70, OC71... And these Ge-transistors were all noisy, had high cutoff currents and were sensible to temperature. My first BC109 marked a great step forward in all these aspects, so I never turned back to germanium.
But hey, if the fun is the challenge in making these fossils play music - there is nothing you can debate about.;)
 
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