Germanium VS Si transistors

[ee]

I have heard from the rumour mill that old Ge transistors sound like tubes,
Is there any truth in that or is it due to use of similiar capacitors and
interstage transformers?

EE

[John Byrns]

In article <F8YV9.12427$Ui4.4...@news1.telusplanet.net>, ee
<ee1000@!hotmail.com> wrote:

Yes.

Regards,

John Byrns

Surf my web pages at, http://www.enteract.com/~jbyrns/index.html

[ee]

Why?

[Patrick Turner]

ee wrote:

I am not too sure that germanium transistors sound like tubes,
or if they do, it possibly could be because the thd is high,
like in old tube circuits that are very average.
Germaniun output transistors don't have much to attract me,
and they used often cheap not so good transformers,
and electro coupling caps, etc.

To my mind, the Germaniun Era of electronics is easily forgetable,
and holds no worthy secrets, not like SET, which largely went unoticed
until some dude hooked up a 211, and went WOW!

I could be wrong, and you are welcome to coax music from Germanium,
and I would suggest class A, but watch out how you bias your amps.

Patrick Turner.

[John Harper]

There's absolutely no physical reason why Ge should sound
significantly different from Si - the semiconductor physics
are identical, apart from a few parameter values such as the
bandgap voltage (~0.2V Ge, ~0.6V Si). I think this has
more to do with nostalgia than anything else. There's
certainly no reason why it should like a tube.

John

"Patrick Turner" <in...@turneraudio.com.au> wrote in message
news:3E28B3C6...@turneraudio.com.au...

[Gary Glaenzer]

John;

 

Interesting term..........'bandgap voltage'........I'd never heard that used before.............where did you pick it up ?

 

Regards

 

G

"John Harper" <jha...@cisco.com> wrote in message news:1042861590.31643@sj-nntpcache-5...

[John Harper]

Actually when I wrote it I wasn't sure it was the right term. What I mean

is the voltage drop across a diode at a modest current (say 1mA), which

is certainly related to the bandgap but I don't think this is the correct

term for it.

 

    John

"Gary Glaenzer" <nobul...@mchsi.com> wrote in message news:fi4W9.29252$1q3.4678@sccrnsc01...

[West]

I believe the different doping material increases the air around stringed
instruments.
west

"John Harper" <jha...@cisco.com> wrote in message
news:1042861590.31643@sj-nntpcache-5...

[West]

Forward bias drop?

west

"John Harper" <jha...@cisco.com> wrote in message news:1042875937.873430@sj-nntpcache-3...

[Oscillatus]

"West" <wes...@gte.net> wrote in
news:v58W9.1516$e34....@nwrddc04.gnilink.net:

> I believe the different doping material increases the air around stringed
> instruments.

Huh? How?

[Patrick Turner]

John Harper wrote:

> There's absolutely no physical reason why Ge should sound
> significantly different from Si - the semiconductor physics
> are identical, apart from a few parameter values such as the
> bandgap voltage (~0.2V Ge, ~0.6V Si). I think this has
> more to do with nostalgia than anything else. There's
> certainly no reason why it should like a tube.

I have never bothered to do an ABx test, so WTF would I know,
now really.
But should one take a look at the transfer characteristics of some
Ge transistors, maybe you find they ain't so hot in a class AB
amp where the bias is low, and X-over distortion high, and NFB is low
because of stability issues caused by the cap coupling and OPT leakage L.

I once tested a Ge power transistor in a car radio, probably OK for
4 watts, using the 12 volt supply, in a class A situation, and
that maybe would be better than a PP amp. But the rest of the circuit wasn't
too wonderful,
and so the whole radio pacakge was a bit sus. Not even proper dual coil
IF transformers, so AF bandwidth is limited...
Poor detector, and so on, so almost any good modern set would be better,
with a chip based power amp, and chip based radio.
Not always the case, as it is true some modern Si gear is attrocious,
and some is OK.

I leave it to the enthusiasts to experiment to find out which is best.

Patrick Turner.

[Patrick Turner]

Oscillatus wrote:

Hmm, air indeed.
Is it breathable? same amount of O2?

I jest, of course, but air and things like "bloom"
are heard by discerning listeners, presumably at concerts,
and also when a system is good.

Patrick Turner.

[to...@nospamprepair.com]

I don't know about the hi fi world, but in guitar amps there definitely is
something smoother sounding about germanium. Some of the earlier solid state
stuff that used them sounds pretty good - I could see where someone might
make more of a comparison to a tube like sound, especially at hard clipping.
I wouldn't have a clue for the scientific reason (.2V forward bias compared
to .6?) though some earlier designs used coupling transformers and I am
quite sure that has something to do with it.
Did recently repair an old heathkit guitar amp with Ge pnp outputs and
that's an amp I would like to own. The Thomas organ built voxes also sound
pretty good.

--
to...@amprepair.com
(615) 591-7556 10am - 6pm Mon thru Fri
please see our website:
www.amprepair.com

"ee" <ee1000@!hotmail.com> wrote in message
news:F8YV9.12427$Ui4.4...@news1.telusplanet.net...

[Fred Nachbaur]

I think you've pinpointed the reason for the perception that Ge has a
unique sound. By the time Si transistors came along, transformers in the
audio path were pretty much ancient history. So what people are hearing
when they talk about a Ge "sound" is, I believe, the transformers rather
than the transistors per se.

I'm still choked that Peavey makes a line of amps they call "TransTube",
implying that they have a "tube sound" -- when all they've done is add
an output transformer to a completely ordinary Si transistor amp.

Cheers,
Fred

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