Whack Germ trannie idea

[Karmasound]

Ok this might be silly but....

since germ trannies sound better when they are warm.


how bout the TRANNIE HEATER! :shock:


What is the optimal temp for germ transistors?


I thought of these old battery heated socks I used to have. Then I thought, maybe I can put a tiny little heater on the transistors to keep the temp stable. Or to warm them up to optimal temp :lol:  :oops:

[GreenEye]

hmm.  Heat tape?

[Peter Snowberg]

They don't necessarily sound any better when warm, but the gain is HIGHLY affected by heat. Just put a Ge transistor in an hFE meter and watch the numbers move as you hold the transistor body with your fingers.

One way to get a really good sounding fuzzface is to match the transistors at the temperature the unit will be used. The only problem is that the unit will be used over a wide range of temperatures. The hall will be cold when you arrive and if there's an audience, by encore time the temp may have risen by 10-20 degrees (F) thanks to body heat.

You just can't win with Ge..... the material is in ultimate control, not the human.

I designed a "Peltier Fuzz" that uses a thermoelectric cell to keep the transistor temps stable to within one degree..... No batteries for that design! :shock:

[puretube]

great idea, Peter!

even cheaper than batteries on the long run...

[Karmasound]

They don't necessarily sound any better when warm, but the gain is HIGHLY affected by heat. Just put a Ge transistor in an hFE meter and watch the numbers move as you hold the transistor body with your fingers.

One way to get a really good sounding fuzzface is to match the transistors at the temperature the unit will be used. The only problem is that the unit will be used over a wide range of temperatures. The hall will be cold when you arrive and if there's an audience, by encore time the temp may have risen by 10-20 degrees (F) thanks to body heat.

You just can't win with Ge..... the material is in ultimate control, not the human.

I designed a "Peltier Fuzz" that uses a thermoelectric cell to keep the transistor temps stable to within one degree..... No batteries for that design! :shock:

So how did that work out?

[Peter Snowberg]

Designed, but never built.

It uses a thermistor with an LM339 wired as a window comparitor to drive a H-bridge that powers the peltier junction.

The LM339 outputs a signal to heat when the thermistor gets too cold, or to cool if it gets too hot. Without a window of no action between heat and cool, it would sit there oscillating all day so we give it a few degrees to be OK with what's happening.

The H-bridge could simply be four MOSFETS, but there are some integrated bridges in SIL packages that are much easier to work with.

Peltiers are fairly power hungry.... I got one to play around with and it takes 75W @ 12V which is 6.25 amps! :shock: And how badly does that click in comparison to a 1mA LFO? ....in a distortion circuit too....  :lol:

[puretube]

http://www.dts-generator.com/main-e.htm

[Paul Perry (Frostwave)]

Does the Ge gain increase with temperature?
I know the LEAKAGE does! :wink: