Tape preamplifier (CB20575E)

With NAB equalization we found this circuit in an English documentation from 1967. The transistors used are germanium types of the time.

Laser Diode Modulator (CB4850E)
This circuit allows modulating a laser diode with low frequency signals. The integrated circuit...
Gain 100 with the 741 (CB902E)
This AC amplifier using the 741 operational amplifier uses a dual supply from 5 to 12 V. The input...
AC Phototransistor (CIR812E)
This circuit is suggested by the Optoelectronics Sourcebook by Texas Instruments when AC signals...