Paraphase amplifier (T389E)

This 6C5 tube circuit was found in a modern tube design manual. The circuit applies to other equivalent triodes.

FET Input Operational Stage (CB14620E)
The presented circuit was found in the National Semiconductor FET Databook. The setting applies to other...
Amplifier for 12 V (CB8962E)
This configuration with the LM383 appears elsewhere on this site. The circuit shown was obtained...
High Impedance Preamplifier (CB941E)
This very high input impedance preamplifier is from a publication of 1977 but can also be mounted...