Hight temp caps. Why and where?

[JasonG]

My guess is there is a trade off. Higher stability in exchange for ?. Where do they belong in audio equipment? I have been checking the web and have not gotten much and none of the books I have read have said much about them.

[R.G.]

Anything that is stable at high temps must be made from materials that are stable at high temps. That may or may not be the characteristics that are good for operation at low temperatures. So often, high temp parts are bigger and may have less performance in other areas, as well as being more expensive.

In general, high temperature rated parts are not needed for effects. There is some reason for using them inside power amplifiers and tube amplifiers where the normal operation of the device can heat the capacitors up. Also, there are places in high power audio crossovers, and so on where the currents involved will cause self heating.

There is no particular inherent virtue in high temperature parts except by accident. For instance, a 105C rated electrolytic may or may not have better performance at low temps than an 85C rated cap.

Use high temperature rated parts... when you have high temps.