Thermal Effect on Transistors

[TrevorP]

Hey,

I was just playing my guitar and noticed that the longer I played with it distorted the better the sound and "clearer" I was getting out of it.

So I know that temperature has an effect on the resistance of a conductor, but how does it affect a transistors output.

My guess it what is happening is as I kept playing it the continuous overdriving slightly heated up the transistors (or maybe more than slightly), and as it got hot it tended to have better even harmonics and less odd harmonics (explaining the better sound).

So basically am I right that the temperature is changing the sound slightly? Or is there some sort of electrical charge built up inside the transistor from continually overdriving it?

-Thanks,

Trevor

 

[Sceadwian]

Simple usage is what's heating the circuit up. Temperature does effect semiconductor function, everything from a diode's forward drop to a transistors gain will change slightly as the circuit warms up.

 

[audioguru]

Many fuzz circuits use old germanium transistors that leak a lot of current as they get warm.
Many fuzz circuits are very poorly designed without any regard for temperature stability.