This amplifier, whose mounting on a printed circuit board was described in Radio Electronics of October 1960, has 35 W of power. The power supply uses a transformer and a set of 5 tubes.
We found this high gain circuit with the LM381 preamplifier in a Radio Electronics from February 1990....
This circuit provides a good audio power from a signal at least 1 V of amplitude. The MOSFET must...
Using a CA3130, operational amplifier with FET, we found this circuit in a 1977 publication. The...