The pentode tube used in this circuit has 1.5 V filament. The circuit is a voltage amplifier with the 1U5 tube.
We have other similar setups on this site. This one is from September 1976 Radio Electronics. The...
This low voltage AC control uses a triac. Any TIC series triac can be used and this device must be...
Using germanium transistors, this amplifier provides a 540mW output power when powered by 9V. We...