This high quality circuit with complementary symmetry was found in an Electronics World of 1966. It can be made with modern transistors like the BD or TIP series.
This preamplifier is recommended by Sanyo and is based on its LA3160 integrated circuit. The...
This reinforcing stages from a 1960s documentation. No information is given about the transformer...
This circuit can use any comparator or even an operational amplifier. We can use the LM339 and the...