Found in an American publication from 1947, this 4-tube amplifier has excellent sound quality. Its source makes use of a transformer.
We have already explored this configuration in several projects on our website. What the circuit does...
P1 on this Radio Shack circuit is a 6 V lamp with current up to 500 mA depending on Q2. The...
The transistors of this timing circuit may be more modern types such as BC548 and BC558. The...