Hello indianajo,
I will sell more transistors at an affordable price
let those who need it benefit
Hello Adason,
I am sorry for my English 🙂
Thanks for the schema. But i have one asy77 transistor 🙁
here is my germanium list. Which other can i use
2sb75
2n1304
2sb172 x2 piece
2sb56 x2 piece
2sb176
Ac132 x2 piece
Ac124
Ac188 x4piece
Ac128
Ac187
2n1853
asy77
Hello john curl,
I agree with you.
I have a lot of modern amplifiers.
Pioneer A-433
Jvc AX-411
Jvc AX-242
Pass F5
3886 Gainclone
Tda 2050
Yamaha Rx-397
Lm4780
like these ...
But the germanium amplifier sound is more warmer.
You want warmth, build a quasi comp output amp like a NAD 250, an Apex AX6 or AX8. According to somebody on this thread, What was the first Complementary AB bipolar amplifiers? quasi comp amps produce even & odd harmonics. He says complimentary output amps tend to produce odd harmonics only. Even harmonics are "warm". I don't know about the receivers you have but the IC amps have complimentary outputs.
Or look into vaccuum tubes. They have a nice distortion at full volume. And they are still making them, at least JJ is.
Or look under instruments & amps at the guitar pedal circuits. Filtering off the odd harmonics is what many guitar pedals do.
John Curl said in that thread that he had an old Telefunken radio with germanium outputs. Telefunken knew what they were doing, and knew the soa limits of germanium that were not published in the datasheets. See that thread about all the greybeards around here that burned up germanium transistors in their youth. The soa rating was not understood or published until a decade after germanium was a dinosaur. I can tell from the box of dead germanium transistors & zeners I bought that Shober the organ builder believed in the "max power, max current limit" fairy.
Or look into vaccuum tubes. They have a nice distortion at full volume. And they are still making them, at least JJ is.
Or look under instruments & amps at the guitar pedal circuits. Filtering off the odd harmonics is what many guitar pedals do.
John Curl said in that thread that he had an old Telefunken radio with germanium outputs. Telefunken knew what they were doing, and knew the soa limits of germanium that were not published in the datasheets. See that thread about all the greybeards around here that burned up germanium transistors in their youth. The soa rating was not understood or published until a decade after germanium was a dinosaur. I can tell from the box of dead germanium transistors & zeners I bought that Shober the organ builder believed in the "max power, max current limit" fairy.
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The same impression I get sometimes, when I check old portable Radios like this, where it is a PPP germanium amp in use:
Distortions in PPP Power Amp (FM/AM Radio TFK Bajazzo TS 301)
Interesting. Are there (maybe anywhere here) the associated schematic so as brand and model No. ?
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Three years ago I spent too much time simming a studio microphone preamp using only Ge devices (SmallBear has good stock, and knows the good from the bad (the bad are good in fuzzes)).
Life is too short. Throw something together, have fun with it. move on.
Attachments
probably the transformer output with no feedback that makes it sound fuller.
the Vbe knee (0.2v) is lower and also leaky so the transistor does not go off as completely as silicon.
the Vbe knee (0.2v) is lower and also leaky so the transistor does not go off as completely as silicon.
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I regret to say that quasi comp amps produce odd harmonics only. Odd harmonics are not a whit colder than even harmonics. For some of us, the base-emitter voltage of 0.2V is an extremely disquieting cicumstance. The nagging question is what causes what in a complex situation.
I had portable radios back in the day that were all germanium and I say germanium has/causes a fundamentally different sound to silicon regardless of the circuits/techniques used.
Are there any modern germanium parts made nowadays, even diodes ?.
It would be interesting to try running a Galena diode instead of silicon (or germanium) detector diode in an AM radio stage.
I think I know the outcome.....early cat's whisker 'crystal' AM radio sets sound fundamentally different to silicon or germanium passive crystal AM radios, and not in a nice way IMHO.
I have auditioned galena in another audio application and it gave me a nearly instant headache.....I repeated the experiment a month later and got the same result so I have not tried again since.
Dan.
I put together a small germanium headphone amp together some years ago, and its great 🙂
GERMANIUM Single ended Class A Headphone Amp.
GERMANIUM Single ended Class A Headphone Amp.
That's a very nice circuit with a good use. I'll see if rediceman's list will fit in.
Why a supply of 6.8Vdc?
Do you have some extra spec's available? Just to be sure, germanium renders different settings.
I calculated (so far) the current source Q4 at some 60mA and output node Q3e-Q4c-R15 at -3.2V.
Amplification is nearly 6x, so suitable from line level (150mV).
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Those were the days of transformer coupled push-pull output stages. The cross-over artifacts are going to be less severe with Ge due to the much lower bandgap voltage, I think a lot of people noticed when Si replaced Ge in stages without proper biasing or bias stabilization?
I suspect Ge is much harder to bias stably anyway, so would have been under-biased for safety, or much larger emitter resistors were used. Thermal issues are important in devices that are destroyed above 75C.
Note that preamps are usually class A. Thus crossover voltage management does not apply, which is a class AB problem applying to power amps. In the late fifties class B was not unknown, particularly with historically important output transformers.
Headphone amps are also probably class AB, or in the primitive past, class B.
IMHO distortion pattern is mainly a function of the RLC components of a circuit. Junction transistors are inherently exponential response devices to an input current, and require other components to tame them down to approximate linear response of output current or voltage to input signal. These other components give a circuit it's signature sound. Germanium responded much more to power history (heat) than they did to input current or voltage, compared to silicon or vacuum tubes. Some vacuum tubes about 1964 like EF86 were quite linear in voltage response.
Headphone amps are also probably class AB, or in the primitive past, class B.
IMHO distortion pattern is mainly a function of the RLC components of a circuit. Junction transistors are inherently exponential response devices to an input current, and require other components to tame them down to approximate linear response of output current or voltage to input signal. These other components give a circuit it's signature sound. Germanium responded much more to power history (heat) than they did to input current or voltage, compared to silicon or vacuum tubes. Some vacuum tubes about 1964 like EF86 were quite linear in voltage response.
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A 6.8 volt supply was about as high as the two nominal 4.8V battery packs would support and listening tests showed it was more than ample given reasonably high efficiency 'phones.
Some of these ancient germanium devices begin to conduct at around 130mv V-BE and the quiescent current of the output stage is about 45 to 55 milliamps depending on temperatures.
I'm afraid I've no other specs on the unit, it was all built and optimised subjectively but it certainly performed very well.
So Q5 is at Vbe 165mV given 50mA (median) and R10 (3R3).
Battery pack (NiMh) of nominal 4.8V (6.8 topcharge value).
So when not in use on charger (on-off-charge switch).
Open loop gain of Q2 is below 1x (est at 0.75x). Not intenionally?
To raise it above 1x, R8 should become 330-220 (& adjust R12).
Do you mind I adept your circuit for rediceman with given semi's?
There are to few to incorporate the volume bufferstage, so that's omitted.
If ok I'll start the calculus.
Battery pack (NiMh) of nominal 4.8V (6.8 topcharge value).
So when not in use on charger (on-off-charge switch).
Open loop gain of Q2 is below 1x (est at 0.75x). Not intenionally?
To raise it above 1x, R8 should become 330-220 (& adjust R12).
Do you mind I adept your circuit for rediceman with given semi's?
There are to few to incorporate the volume bufferstage, so that's omitted.
If ok I'll start the calculus.
Preamplifiers didn't have a sound in isolation, you had to put the signal through a power amp to hear it, and that would also have been germanium at the time, is the point.
Anyway the idea that germanium and silicon sounds different even in the same circuitry doesn't convince me because the circuitry was not the same: bias points, gains, amount of feedback and choice of pnp v. npn was all different depending on devices available, each circuit is designed with particular devices in mind,
and solid state circuit sophistication was increasing over the period as Si replaced Ge.
True, those early amplifier germanium output amplifiers stages were transformer interstage coupled usually, but so were the early silicon portable radios that replaced them.
Sure, but I still maintain those otherwise similar early battery portable radios sounded fundamentally different according to Ge/Si same but different circuits of the time.
It might be fun to compare a universal unity gain line buffer design that could be implemented in either transistor type with appropriate minor mods.....ie component values only.
Ideas anybody ?.
Dan.