This 8-tube amplifier with 12 W output was found in an American publication from 1947. The output is in counterphase with pentode tubes.
We found this circuit in an English magazine from 1976. The magazine no longer exists, but just...
The figure shows a simple way to have emergency power for a 9 V circuit powered by a source. If...
Found in an Electronic Design from the 90's, this circuit supplies voltages according to the...