This excellent tube preamplifier was found in Radio Electronics magazine from July 1958. The power supply was not included. The circuit has several inputs.
This circuit reinforces signals in a frequency range between 1500 and 2000 Hz for use in...
When a small air current reaches the piezoelectric sensor, a small audio signal is generated and...
This circuit is from a Poptronics, American magazine from August 2000. The circuit can be...