This circuit is placed between the instrument pickup and the amplifier input. The same version can be found from other sources in this section. This is from an English magazine from the 80s.
The CMOS 4046 integrated circuit is not very common today, consisting of a very efficient PLL for...
This circuit turns on an old cassette recorder when the telephone rings, thus enabling the...
This circuit can be used in panel signaling with common incandescent lamp. The lamp will flash at a...