6AC7 Amplifier (T450E)

Obtained in MIT documentation, this 4-stage circuit has high gain for small signals. The power supply sources 150 V.

100 mA Piezoelectric Generator (CB25413E)
The circuit in the figure is suggested by Linear Technologies (www.linear.com) and consists of a...
Differential Amplifier (CB6546E)
This circuit was found in an American publication from 1968. The transistors are from the time,...
Car audio booster (CB7253E)
Found in a 1990 Hobbyst Handbook this circuit has an output power of a few tens of watts and...