simple quasi-complementary Germanium PNP transistors

Discussion in 'The Projects Forum' started by CRY&PRAY, Feb 7, 2014.

  1. CRY&PRAY

    Thread Starter Member

    Jan 6, 2014
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    Hello guys :) i've found some old germanium transistors (ASZ15) and i would like to build an amp with them, nothing too complex, just a amp with that germanium sound ;) just i don't know where to start, i want to create a simple (using stuff that i can recover form old things) quasi complementary (they're both PNP) amp, any ideas? i can't even found a datasheet about them! (kinda found something about NTE121 that should be similar)

    -Francesco
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    most of the old AM radios were PNP Class A (GM car radios, for example).

    Poor temperature stability and questionable reliability - class A type troubles. I don't know what "germanium sound" you are looking for Unless you have fond memories of trying to listen to a baseball game on a 5 watt car radio as your father drove down some road while the noisy bias-ply tires cracked over every rock and expansion joint to drown out anything coming out of the single 4 ohm speaker. The gurgling V8 that was tuned too richly confused your ear into thinking it was some rich bass.
     
  3. TANDBERGEREN

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    Jan 20, 2014
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  4. takao21203

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    Apr 28, 2012
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    there is a specific Wah-Wah particular to Germanium transistors. 1968 people were reportedly able to touch it.

    But these days it is no longer so easy.

    One time in the late 1980s I had an old tape player, not the plastic ones with pushbuttons, but one with kind of a lever. It did not sound that much outer space.

    Soon I dismantled it, and it had quite a couple of rectangular germanium thingies. Same which I cracked open with pliers and a white liquid poured out. eventually I even came accross the internal contact wires.

    Recently some years ago I made a joultheif with a low-hFE Germanium transistors + very thin wire wound on a core memory ringcore.

    It worked from slightly lower voltage but no revolutionary breakthrough.

    For sure simple germanium circuits produce more distortion, because these old germanium transistors are more leaky, and their hFE can be quite low.

    They are used for eguitar effect circuits, and at some places can be seen on offer for quite high prices.

    Maybe it is enough to have just one of these in a regular transistor circuit- at some place where it can distribute it's noise.
     
  5. CRY&PRAY

    Thread Starter Member

    Jan 6, 2014
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    yep i saw it, i would like to replace the ASZ16 with a normal PNP transistor as i don't have it, and know the transformers winiding, i have some audio transformer, i'll try them tomorrow :) and someone knows the language in that pic just to understand what's written
     
  6. CRY&PRAY

    Thread Starter Member

    Jan 6, 2014
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    maybe build a simple class A amp? these 4 transistor i found in an old OCB or something similar linear amp (might be wrong) rated somewhere 100 watt in my grandad canteen, with all junks in there i could only recover these 4 guys, i wanted to give them a place and not sitting there watching me :), if a simple headphone class A amp (stereo i have 2 of these) is a good idea, how can i build it? i would like to use stuff that i can find on boards and i don't know the ratings for these guys in a class A amp, a simple sketch would be apreciated :)
     
  7. Rolf Zetterberg

    Member

    Sep 20, 2008
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    I wouldn't even look at power amplifiers with transformers.Transformers were used in early simple car radio boosters to raise the output from the low voltage available in a car or in early Ge amplifiers.
    Of course it's possible to build almost any Ge power amp that has a voltage that the ASZ15 can cope with.There are lots to choose from.
    Some data on the transistor here:
    http://85.92.85.233/forum/forum/showthread.php?p=567024

    As far as I remember,the ASZ15 was often used as a switching transistor and in power supplies,but I can't see why it won't work as an amplifier.
    Of course it's not the best transistor in the world,but' that's a different story.
     
  8. CRY&PRAY

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    Jan 6, 2014
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  9. CRY&PRAY

    Thread Starter Member

    Jan 6, 2014
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    yep, i'm not trying to make a power amp to driver my huge speakers, just wanted to make these things sound, even a headphone amp is ok, i want to hear again that hell of a noise from these transistor, i kinda love it :3
     
  10. TANDBERGEREN

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    Jan 20, 2014
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    Theese Germaniumtransistors isn't the first choise to make a class A amplifier to drive huge speakers.
    Note: You only can dissipate 30W in theese. Could probable give You just a couple usable watts for your speakers. Not in the region of more than 3-5W in the most optimistic guesses.
     
  11. CRY&PRAY

    Thread Starter Member

    Jan 6, 2014
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    that's okay, gonna drive some headphones/Beringher EP2000 amp, going to build a cheap but cool GERMANIUM preamp that's gonna dissipate heat like a hot stove and explode ;) but i have pnp transistors and i don't know how to build one!, or i can go class D single ended :D
     
  12. TANDBERGEREN

    Member

    Jan 20, 2014
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    Class D with theese?
    No way.
     
  13. CRY&PRAY

    Thread Starter Member

    Jan 6, 2014
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    yep, the maximum frequency, didn't saw :)
     
  14. CRY&PRAY

    Thread Starter Member

    Jan 6, 2014
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    :eek: So any idea ? just a simple class A pnp amp, but i don't know ho to work with an PNP and it's germanium that means different voltages and all that stuff
     
  15. MrChips

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    Oct 2, 2009
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    What is the "germanium sound"?

    Never heard of it.

    If I were you I would scrap the idea and go with silicon transistors.
     
  16. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Germanium sound.....hmm!

    It's sounds more like..Germ...Germ...Germ...Germ...Germ...Germ...!
     
  17. CRY&PRAY

    Thread Starter Member

    Jan 6, 2014
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    that sound that i'm searching really is that scrappy, non clean sound of them, that's why! btw it's just a simple project, and i'm still in pain on how to do a simple class A PNP amp, i don't know where to start :(
     
  18. R!f@@

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  19. MrChips

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    If what you want is a scrappy, unclean sound from an amplifier I am sure we can do that with a simple one-transistor silicon NPN or PNP amplifier circuit.

    Where is audioguru when you need him?
     
  20. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    You have to ETO to AG
     
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