Quote:
Originally Posted by fenson
No ;but it is ture, IMO maybe something to do with electron flow , the warmer things get the faster they flow.
|
Auggghhh!
OK, I'll calm down now. Sorry, but I'm an Electrical Engineer.
Electrons always "flow" pretty reliably at the speed of light. Temperature in this earthly realm is not a significant factor.
Tubes use heaters to warm up pieces of doped metal in order to create conditions that allow a lot of "free" electrons to become available from the metal. There is of course a strong function of temperature here, but the parts of the tube that are heated up by the filament reach a stable temperature pretty quickly - in less than a couple of minutes in most cases. After that, the tube behaves in a very consistent way. It certainly does not take 30 minutes.
If there is any difference in performance that appears to be a function time and temperature, it concerns other components. The most notable ones are the old school carbon resistors found in virtually all amps; in most cases the value of the resistor will go up a bit as it heats up. For the most part, the capacitors are unaffected, as are the transformers.
Remember, relative to a lot of things the temperature inside an amp chassis isn't really that hot. Cloth wires don't burst into flame, and many an old doobie has been found inside amp heads utterly unsmoked. Kinda dried out, but not smoked.
In most cases, an amp like a DR will achieve a stable chassis operating temperature in about 30 minutes. This only means that the resistors are now at whatever values they may settle at, but I don't expect the variations to amount to much.
I would not discount the psychological effect - I think that is really the majority cause. It just "seems right" that the amp should sound better when it is "warmed up", but in my own experience of many years on stage I have just not found this to be true. My old tube amps sound good within the first minute and stay there all night long. And that is how it should work.