Bass control (CB8722E)

Found in a 1993 Electronics Hobbyst Handbook, this passive circuit can be used with common preamplifiers and amplifiers.

Overcurrent oscillator (CB9627E)
The frequency of this circuit depends on the crystal. The transistor supports a modern equivalent. We...
High-gain composite amplifier (CB8069E)
Indicated in Maxim's documentation from the 90's, this circuit has a gain of 40 dB and an output...
Timer with 741 (CB12281E)
The time obtained in this circuit, from a 1978 publication, depends on R3 and C. R3 can have...