This simple TTL digital amplifier uses NAND gates and a high impedance speaker.
This is an old circuit with a unijunction transistor from that time. We found it in a Radio...
This conventional 4 channel circuit with the 4017 and 555 was found in the November 1991 Radio...
This circuit is from a 2005 Linear Technology manual. The circuit uses an LT6700-3 and has an...
