Check the listing for details. General Purpose Audio Amp / Discrete Components / Ham Radio. Condition: New. Listed at 6.95 USD. After several months of off-and-on development and testing (and with some help from Steve AA7U) the well-known general-purpose 3-or-4 stage audio amp by Richard Andersen, KE3IJ (SK) is now ready for prime time. You can use it with all four stages or you can bypass the first stage using jumper blocks. The amplifier has a 2N3904/2N3906 push-pull output stage, and it runs on 12VDC (with a built-in 9V regulator. A diode provides reverse-polarity protection. If you’d like to skip the usual (boring) LM386 and put out some real power (2+ Watts) using good ol’ discrete components, give KE3IJ’s amp a try. The amplifier is available as a bare PCB, a kit of PCB and all components, or as an assembled and text unit. Assembled units are produced on demand and require up to 14 days before shipping.