We found this circuit in a publication of 1991. The audio amplifier is an operational that admits equivalent.
November 2016 - NXP ARM Cortex microcontrollers for serial interfacing applications, NXP 32-bit...
This simple earphone receiver was sold in the 1960s in Japan. The circuit uses a single germanium...
Rumble is a low frequency rumble that occurs with turntables. If the reader recovers recordings on...