This circuit was found in Philips documentation from 1965. No information was given about the transformer. Transistors are from the era.
This circuit was originally designed with the operational 747 which is rare today. However, the...
This circuit was found in a 1975 technical publication. The circuit can be designed with 741...
The TDA2613 is the mono version of the TDA1521A and has pinouts compatible with an integrated...