Ge Transistors

Frequently asked question on transistors: types, substitutions, how to test, use and misuse them.

Ge Transistors

Postby gurishka » 03 Apr 2012, 19:42

Hey all,
I just recently got in a batch of some PNP Ge transistors (GT308B) from Moscow with the Hfe ranging from 39-59....
Any ideas on what I can use them for? I was hoping that their Hfe would be up around 80 or so to use them in some Fuzz Tonebenders and the like....are they any good still?

All suggestions welcome.
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Re: Ge Transistors

Postby PokeyPete » 03 Apr 2012, 22:06

Sure they are! The higher gain ones would make rangemasters. Or, Q1 in a fuzzface.
Traditionally tonebenders use 70 to 100 gain transistors, but if I remember correctly
Fulltone's Soulbender reversed the order of gains and used transistors with gains of
78 to 89 as Q1, 67 to 77 for Q2, and 45 to 66 for Q1. (The gain ranges may not be
exact but they are very close.) You can take the lower gain transistors and put them
in darlington pairs to increase their gains by a good bit. At the very least you can
use each one as a diode by only using the base and emitter. I'm sure others will
chime in with more options. :D
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if he takes no other counsel than his own. He that is taught
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Re: Ge Transistors

Postby gurishka » 04 Apr 2012, 02:33

Would making them a darlington pair be a bad thing? :(
Hfe1 x Hfe2 etc...
Wouldn't it be too high? Or again it wouldn't matter having the hfe 1000 :scratch:
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Re: Ge Transistors

Postby bato001 » 04 Apr 2012, 04:15

Build a Big Muff with a .1uF electrolytic between Q2 and Q3 (instead of a ceramic .1 uF cap) and use your low gain germaniums for the Q2 and Q3 transistors and 2n5088's or similar high hfe transistors for Q1 and Q4.
"Ever wondered how some of your favourite guitar players got their tone? Me too. Probably a good amp and lots of practice." Little Lord Electronics Homepage

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Re: Ge Transistors

Postby PokeyPete » 04 Apr 2012, 09:07

gurishka wrote:Would making them a darlington pair be a bad thing? :(
Hfe1 x Hfe2 etc...
Wouldn't it be too high? Or again it wouldn't matter having the hfe 1000 :scratch:

gurishka, I'm just throwing ideas at you. In the '50s and '60s when these things were just becoming popular,
they were used for all sorts of purposes. Not just amplification. They were used as switches.....they turned on
light bulbs...they activated relays. They revolutionized computer design. If you limit them to the few stompbox
circuits that famously used them, then maybe your collection will be mostly wasted. But if you treat them as just
another transistor, there are lots of things you can do with them.
“No man is so foolish but he may sometimes give another
good counsel, and no man so wise that he may not easily err
if he takes no other counsel than his own. He that is taught
only by himself has a fool for a master.”
–Hunter S. Thompson

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gurishka (04 Apr 2012, 12:44)
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Re: Ge Transistors

Postby briggs » 04 Apr 2012, 10:06

http://freestompboxes.org/viewtopic.php?f=13&t=16858 - Perfect gain ranges for the Rangemaster mkII
Image

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Re: Ge Transistors

Postby gurishka » 04 Apr 2012, 12:48

Hey PokeyPete and briggs, thanks very much for the ideas...I love the La Revolution Deux site briggs....I try and pop over and check it out when I have some free time.... any and all help is appreciated very much. :)

So you think a Rangemaster Mk II is the way to go? I was thinking some of those Bronto Boosts and Skyripper Fuzz pedals by NVN/Joe Gagan would be good but they're obviously a bit down on Hfe... :(

Would they still work in a Tonebender?
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Re: Ge Transistors

Postby gurishka » 04 Apr 2012, 12:55

Hey briggs have you read this article?
http://www.smallbearelec.com/HowTos/GeD ... nPairs.htm

I'm finding it interesting and for a noob like me, quite scary to think about trying to implement... :S
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Re: Ge Transistors

Postby jrod » 04 Apr 2012, 14:15

^^^HAHA I was just going to post that article for you check out!

bato001 wrote:Build a Big Muff with a .1uF electrolytic between Q2 and Q3 (instead of a ceramic .1 uF cap) and use your low gain germaniums for the Q2 and Q3 transistors and 2n5088's or similar high hfe transistors for Q1 and Q4.


bato001, why an electro instead of ceramic or film? :scratch:
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Ge's

Postby Godebut » 20 Jan 2014, 05:12

Germicide circuit says its good for low,leaky ge's? Not verified true by me personally
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