Audio Cable Tester (CB3827E)

This simple circuit tests both monophonic and other two-wire audio cables. The circuit is powered by two common batteries.

AD Converter Comparator (CB20160E)
This circuit is from the manual of the components used, from the 80s. The circuit is valid for...
RIAA Preamplifier (CB19519E)
This circuit from the 1980s uses an operational amplifier that is uncommon today. The circuit can...
Debouncer circuit (CB7949E)
This "debouncer" was found in Popular Electronics, using TTL technology. For this reason, it can be...