Putting some germanium transistors to use

[spi]

I recently ordered a small number Ge transistors. I measured them this week using the RG Keen method. I found a few that are usable in some circuits I'd like to build, but there's also a few outside of ranges recommended for the circuits I know about.

One pair is 135 and 200 Hfe (both around 80 ma leakage). They are higher than what is usually recommended, but could these work in a tonebender mk 1.5? Is there some other circuit these would work in?

The other one is only 10 Hfe with 32 ma leakage. I'm guessing this is too low for anything?

 

[andare]

The Analogman Peppermint Fuzz is a fuzz face with high gain Ge trannies. Haven't tried it myself but I'm going to because I also just bought some of those high gainers.

I also want to try a Rush Pep Box because with regular transistors it's underwhelming.

For Fuzz Faces in general just get the voltage Right. You can decrease the gain by lowering the 100k feedback resistor. You can also try adding a small resistor to ground on the emitters. 100R for a start.

I was told here that a Tone Bender Mk1.5 should have a voltage of -8V on Q2c instead of -4.5V like a Fuzz Face.

That's all I have!

 

[szukalski]

The other one is only 10 Hfe with 32 ma leakage. I'm guessing this is too low for anything?

Use it as a diode.

 

[benny_profane]

The other one is only 10 Hfe with 32 ma leakage. I'm guessing this is too low for anything?

You could use it as a part of a Darlington or Sziklai pair.

Germanium Darlington Pairs

 

[BuddytheReow]

You could use it as a part of a Darlington or Sziklai pair.

Germanium Darlington Pairs

Just note that leakage will get amplified too. Not just hfe

 

[mdc]

Tone Bender MKIII/IV are probably one of the most forgiving vintage Ge circuits and (imo) the best sounding tone bender.

 

[spi]

I have an TB mk3 that I'm not in love with. I might try swapping Ge transistors--maybe I'll find that these would work in it (especially if the low gain one works in a darlington pair), and I can harvest the transistors in it now for other use.

 

[Betty Wont]

The 135 would be perfect for Q3 in a Buzzaround.

 

[spi]

You could use it as a part of a Darlington or Sziklai pair.

Germanium Darlington Pairs

Thanks for this idea. I swapped it into both Q1 and Q2 of my tonebender mk3. When in Q1, it wouldn't properly bias and the fuzz sounded too gated. But when I put it in Q2, it biased OK and sounds pretty decent. It sounds less smooth than what I had before, more gritty in good way.

Now I have a decent transistor I pulled from the tonebender to use elsewhere.