Germanium - how do they work?

[StopReferencing]

So I think today I experienced my first "weather fucked up my pedals" bummer. The culprit:

AC125 and OC75 transistors, IIRC. Had to bust it open and re-adjust the bias on the fuzz side to get the cleanup to sound decent. Any of you guys gig with temperamental (no pun intended) Ge pedals?

[kosta]

So gnarly in NYC today... Especially this morning! No Ge insights, just NY weather sympathy.

[McSpunckle]

Badly, it would appear.

[masked elwood]

marc ford (when in the black crowes) used to have small cooler next to his pedalboard. he liked his fuzz faces before they warmed up so he'd change them between songs. the cooler housed a couple spares on ice.



seems extreme to me. but the fukker has huge tone so......

[devnulljp]

I think we should get the PC overclocking guys on board with this and get peltier-based pedal temp regulators for our pedal boards. That would be awesome.
And can you imagine how much fun TGP would have with arguing over temperature differences, coolant materials, colling rates, rates of warmup ... I spot a hole in the corksniffer market

But it always pays to keep a Meathead on standby just in case.

[tuffteef]

pedal mittens?

[Eric!]

The Sun Face I had sounded better warmed up, case in point, after playing with it on for a while.
Great tone, unreliable tone

[nbabmf]

I've had a few germanium fuzzes that absolutely had to be warm to play. This was long before I knew what bias was.


Also...

pedal mittens?

My girlfriend has offered on more than one occasion to knit me pedal socks.

[bennybanana]

Ive got a Creepy Fingers Fuzz Nugget that sounds better warm...is like dogsick when it was winter round here, bu now spring has sprung it sounds like i always hoped it would!

[culturejam]

Here's a brief (and not particularly technical) rundown of what's going on:

The gain of germanium transistors (and to some small extent Silicon as well) is always relative (directly proportional) to temperature. When temperature rises, so does gain; the inverse is also true. This is a characteristic of germanium, and it is one of the primary reasons that it was replaced by Silicon, which has much better stability with regards to temperature fluctuation.

I should think that lower-gain transistors sound better after they warm up, and higher-gain transistors sound best when cooler.

You can somewhat mitigate this problem by adding some additional temp stabilization resistors...but this changes the sound, of course, and increases the complexity of the circuit. I'm also thinking there must be a way to adjust the bias automatically as a function of temperature change....maybe a thermistor? Surely someone would have done it already if it were a simple solution.

I feel like the best option, if you must use germanium, is to have an adjustable bias pot mounted *outside*.

I personally advocate for using silicon and tweaking the circuit to make it sound as close to germanium as possible.

[nbabmf]

I want to say Dunlop's most recent Fuzz Face reissues have a thermistor for an emitter resistor. I'm sure I'll come across one, and I'll take a hair dryer to it while playing...

[culturejam]

I want to say Dunlop's most recent Fuzz Face reissues have a thermistor for an emitter resistor. I'm sure I'll come across one, and I'll take a hair dryer to it while playing...

If they are real germanium transistors, you can simply lightly place your finger on the casing. Within 10 seconds, the gain will have increased a fair bit.

I'd love to see a gut shot of one of those to see about that thermistor.