This circuit was found in the January 1999 issue of Electronics Now magazine. The circuit uses an integrated circuit from the period and has earphone listening.
This power source was found in an old Argentine publication from 1973. The transistor could be the...
With this circuit it is possible to monitor a signal that is being recorded on an old tape...
This circuit is from a 70s documentation. The maximum sampling rate is 800 Hz. The operational...