The operational amplifier for this tone control found in a 1977 Signetics manual may be the 741. The power supply must be symmetrical and the signal cables short. The bass gain is 20 dB.
Two sensors are used in this simple remote-control circuit, one to switch on and one to switch off the...
Using old germanium transistors like the CK722, this circuit has good gain. We found it in a...
We found this configuration in a 1974 publication. Transistors can be replaced with equivalents such as...