auto-bias vs adjustable bias

Tubes Asylum

Questions about tubes and gear that glows. FAQ

24.29.119.117

I UNderstand the difference between fixed and auto-bias circuits. However, I've seen a number of amplifiers which use auto-bias designs
that allow one to use a number of different output tubes. I've always wondered how these circuts work. Does the designer find a common set of voltages which somehow fits the parameters of all the possible output tubes, or are there feedback networks in which the circuits somehow adjust to the characteristics of the tubes. Also, how do amplifiers maintain correct bias in the face of such variables as changes in line current and tube age. Any help from you experts would be welcome. Thanks

This post is made possible by the generous support of people like you and our sponsors:

The Cable Cooker

Topic - auto-bias vs adjustable bias - Peter 17:32:39 06/24/01 (0)

You can not post to an archived thread.