This wired control circuit serves both volume and balance between channels. We found it in Radio Electronics magazine from August 1968. Transistors are common general-purpose types
We can implement this filter with more modern equivalent operational amplifiers, since the LM110 is...
This stethoscope or amplifier for hearing aid using a crystal headset and microphone was found in a...
The normal use of a 4520 as a divide-by-16 counter is shown in Figure bellow. In the normal...