This RIAA equalizer preamp was found in a 1990s schematic. The transistors are an old version of the BC549 that can be used as a replacement. Signal input and output cable must be shielded.
This circuit shows how to control an astable configuration using the 555 IC. The control signal is...
Found in the August 1994 issue of Electronics Now, this CMOS circuit uses the 4046, which is...
This is the transmitter for the previous circuit. We found it in a 90s Electronics Now. The...