| aldovan |
Friends
Anyone get good results using a Germanium transistor in a output stage ?
Aldovan
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| runebivrin |
| Yep, not too shabby for a 60's design. It's about as useful as two tin cups with a piece of string between them. :D |
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| ilimzn |
| Why not give us a few good reasons to try them, given all the silicon abundance available? It would be a nice way to start a constructive discussion... |
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| aldovan |
Ok, have a lot of silicon transistors today and the sound quality remains very inferior to old tubes .
Germanium transistors do not can be a new option for superior quality ?
In my tests with Mosfets, this device have a superior THD when compared with bipolars...
The modern industry have others options? For me, NO !!!
The best option is the return to past !!! |
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| destroyer X |
Now we have a good reason to start a discussion.
Big field town was also great!
regards,
Carlos |
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| Conrad Hoffman |
| Germanium devices of old were leaky, highly temperature sensitive, and hard to stabilize. Reliability wasn't as good as today's devices either. IMHO, the perfect device for hi-end audio! Seriously, they do have one advantage. They turn on at or near zero volts. That's why germanium diodes are still used for some small signal RF applications- you can still buy a 1N270. If you could keep the thermal problems under control, there might be the possibility of lower inherent crossover distortion. I didn't read the old stuff, so sorry if this has already been mentioned. |
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| aldovan |
Obrigadooo,
Thanks, the Brazil is really beautifull...
Aldovan |
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| aldovan |
Temperature do not is a problem, I can use liquid oxygen or a refrigerator chip in the Germanium device...
Seriously, a good termal project help for avoid problems.
In others words, Mosfets have a higher distortion wheen compared to bipolar and is the most used output transistor today...
Aldovan |
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| Eva |
After so many years trying to achieve better and better linearity and reliability in audio electronics, we have to face the sad truth about the human being:
1 - We love distortion and metaphysics :clown:
2 - Amplifier people doesn't want to learn about loudspeakers and acoustics ;) |
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| destroyer X |
Now we have Germanium as "the solution"
Já senti que o amigo é chegado à polêmicas, ou, no mínimo, tem certas inclinações para escandalizar a malta.
I already have perceived you have great intentions into this thread.
regards,
Carlos |
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| poynton |
What transistors would you use in the output ?
Presumably PNP not NPN.
OC28 ? |
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| aldovan |
Carlos
Eu ouço apenas valvulados há 10 anos.
O som das válvulas é bem superior, principalmente dos triodos.
Porém fiz algumas experiências com Germânio e realmente gostei, achei o som melhor que MOSFETs, Bipolares e outras sucatas do tipo solid devices...
Apenas queria saber a opinião dos Yankees e percebi que eles chutam demais. Deveriam sentar numa bancada, na frente de um scope e de um audio generator e fazer uns testes, para depois fazer testes auditivos.
Os caras comparam transistores atuais com os primeiros germânios dos anos 50, daí não dá...
Antes dos yankees darem opiniões idiotas deveriam pesquisar primeiro.
Há transistores de Germânio com 30A de coletor e os de áudio respondem no mínimo até 300KHz...
Aldovan |
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| destroyer X |
He post very few posts since 2005.... the majority of his posts were made in this thread.
So...he has not experience and forgot that we cannot use our native language, portuguese, we can only into direct mails...the language here, because International forum, is the main International language...the English.
If we make comments in our own language, we have the obligation to offer a version, the most precise possible version.
He said that he is not kidding...that really he have perceived sonic qualities into Germanium output, also he said that there are units that can work into several kilohertz...said that sounds excelent.
He confirmed that he thinks tube sound is better, also that he dislike Field Effect and do not think BGT is the best option...not the silicon transistor!
He said that people could try some Germanium....to do in real life an experience, not to dennie that possibility without research in real life.. he said that people will be surprised.
regards,
Carlos. |
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| unclejed613 |
and we could use 2SB54 for the diff amp? or maybe 2N107's..... after all, don't we miss the hiss? in the good old days, we could tell when an amp was on by listening to the background hiss (or hum as the case may be)......
can you tell i'm being facetious here????? ;-) |
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| CBS240 |
| quote: | Originally posted by aldovan
Ok, have a lot of silicon transistors today and the sound quality remains very inferior to old tubes .
Germanium transistors do not can be a new option for superior quality ?
In my tests with Mosfets, this device have a superior THD when compared with bipolars...
The modern industry have others options? For me, NO !!!
The best option is the return to past !!! |
There are bad tube designs as well as good ones. Same goes for solid state.
| quote: | Originally posted by Eva
After so many years trying to achieve better and better linearity and reliability in audio electronics, we have to face the sad truth about the human being:
1 - We love distortion and metaphysics :clown:
2 - Amplifier people doesn't want to learn about loudspeakers and acoustics ;) |
I agree. Whether an amp "sounds" good is too subjective to base this aurgument on. To some people with some speakers, acuracy doesn't mean it sounds better. What we need here is some actual numbers. A kit in which the outputs can be changed easily from silicon to germainium devices of somewhat similar 'properties' is needed to better compare and anylize any real differences.
Might be interesting if any of you folks with germainium outputs feel inclined to go experimenting...:dodgy: |
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| destroyer X |
he said exist Germanium units that can work into kilohertz...well...i also never had one unit alike that in my hands.
But....let's wait to listen what he has to say.
A lot of things he said made sense to me...as tube sound, triode sound use to be fine... i know that distorts too much to measurements...but sound is fine even with those distortions.
I also remember that Germaniun units sounded fine...one of the best open rell tape recorders i could listen made use of Germanium units...low power units, of course.
I want to remember folks, that despite the tradition to design amplifier using Megahertz transistors, that audio is low frequencies...from 20 to 20 Kilohertz... and the use of high frequency transistors, HF units, is also non sense and we use to accept that as a rule..so...we have to be flexible, as some folk can enter and tell us that kind of truth we do not like to listen.
regards,
Carlos |
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| aldovan |
Ok, but 2N107 is a very old point-contact obsolete transistor.
Have very good more modern germanium options.
And until today the guitar mans prefer germanium in the pedals because is more smooth...
The tubes is old and is superior to Mosfets.
But I will finish this discussion here, because the peoples only will like the germanium sound when listen a good germanium amplifier.
Words is only words and Mosfet is only Mosfets, nothing more...
Aldovan |
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| destroyer X |
Was a Philips, Miniwatt tubes and Ibrape union result...the kit was the result of those three companies that made part of Brazilian Philips.... now a days, Philips here works on Sound, Television and home and Industrial lamps.
Miniwatt tubes are closed, of course... and the Brazilian Industry of parts (Ibrape) is closed too.
M-150 was the code number....unfortunatelly i have not the schematic.. i am still searching for it.
Direct coupled, silicon transistors were used to the kits, good units, low noise units and BDY Silicon transistor into the output...the old heavy units, steel case.
BUT...into the VAS stage (was bootstrapped) they decided to use an AD140.... an old Germanium transistor used into Auto radios output stage....not more than 10 watts dissipation and not a big voltage from colector to emitter...current was not big.... i cannot remember but was small, 1 or 2 amperes only.... and they decide to use that one.... when they had silicon to use into that position, including BD140 and others..... Texas had their good units too...and Philips had enougth transistors...but they decide to use a Germanium into the Vas...why?
Well...Aldovan give up....he quit to discuss.... a pity as he did not have informed us the Germanium models he was talking about...he said people has to listen to believe... i do agree about that.... we cannot convince..people have to test, to listen, and to realise by themselves.... this works...words or numbers do not works... we cannot convince no one...people convince themselves..but they have to be opened to try, to check, to produce experiences, to construct, to try....not to dennie in advance without try.
regards,
Carlos |
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| unclejed613 |
| actually our shop repaired a "modified" fuzz pedal last week. the complaint was that the fuzz effect sounded raspy and cut off rather than a smooth transition from fuzz to clean as the note sustained. the problem? one of the silicon diodes was replaced with a 1N270 germanium (apparently one of the "mods" found on the net). the imbalance in conduction voltages caused a lot of squirrely things to happen in the pedal. also take notice that germanium conduction curves are much more nonlinear than silicon, and this may have a lot to do with unpredictable types of distortion (the conduction voltage drop changes with the current a lot more than in silicon). i call germanium a "sloppy" diode (also because of it's high reverse leakage current which increases with age) |
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| ilimzn |
This reminds me of a recent discussion on a native forum I took part in.
In principle, there is no reason why germanium would be any worse, and in fact there may be good reason why it could be better, IF (and this is a very BIG if) modern manufacturing techniques were used. Germanium has better conductivity and even in the old days when semiconductor 'metallurgy' was in it's infancy, formed pretty high gain and high current devices.
Even then, there remains one big problem, and that is the very considerable difficulty of passivating germanium dies. In silicon, we just make Sio2, which is stable and a very good passivator. Germanium does not form any stable surface oxides. In general, this was the reason for introducing metal and glass cases - the substrate was soldered (as germanium solders quite well), and being 'on the other side' of the surface with the actual junctions, gave little chance of diffusion (in effect junction contamination) during it's expected lifetime. but on the top, the die was covered with aneutral agent (silicone grease...) and hermetically sealed. No such thing as plastic case germanium!
Today we have SiGe processes, but these are mostly FETs.
The crux of the matter is, most if not all of the assertions above do not apply. Germanium technology died a quiet death in the early 70s and even though some of the parts are still available (and made!) today, and germanium prices are at an all-time low, the fact remains it's early semiconductor technology, a sort of NOS. Not fair comparing it with, say, NOS tubes, as these were already mature enough even for WW2 era NOS - it's an equivalent of what germanium semis would be if they continued to be developed into the late 80s and early 90s.
Could an amp be made with germanium tansistors? Certainly - keeping in mind the limited available selection. Could it sound good? Again, i have no doubts - if you ahve enough money, there are plenty of techniques which largely circumvent the part's 'failings' compared to silicon. The question is, though, would it be better, and at what price, if any?
In the meantime, here's a link to browse, to see what was available back then - the more intrepid can go a few levels up and see the rest of the characteristics for many germanium types:
http://www.ginko.de/user/franz.hamb...mi/geltmax.html |
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| darkfenriz |
For the reasons you've mentioned (oxides!!) pure germanium is not very likely to come back in "new shell" and modern technology.
It's unlike modern compound semis like SiGe or GaAs and others...
But keep in mind that many posters in this thread seem to believe, that technology is like wine or violin, the older the better.
regards
Adam |
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| destroyer X |
Was very good to see them once again...they made part of my young days.
regards,
Carlos |
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| andy_c |
| quote: | Originally posted by aldovan
Antes dos yankees darem opiniões idiotas deveriam pesquisar primeiro. |
Translated into English, this means "I like Germanium".
Ahahahahaha. Hope this helps :clown: |
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| anatech |
Interesting.
I built and had (until recently) a germanium type amplifier I built when I attended Ryerson in Toronto. The complimentary outputs were ACxxx I think. I may still have some of those pairs. It sounded okay, better than some other cheapie amps.
I think a worthwhile project would be a headphone amplifier. The reason it that it is a real amplifier circuit, but the voltages and currents are low enough so that other parts may be used.
Carlos, this sounds like something you can play with if you are so inclined. Base on "Blameless" or SymAsym with low voltages. Rails at 9 VDC ~ 15 VDC might work out well.
-Chris |
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