Thanks to you guys for referencing Southwest Technical Products, and especially to you Francis, for providing that link. It's real trip down memory lane. The first time I soldered a component to a circuit board, it was to build one of their strobe light kits. I had never seen a catalog, but learned about them from the hobbyist magazines. Later, the first PA company I worked for had a "rack" of a dozen Universal Tiger amps that the owner had built himself -- about 10 of which could be counted on to work at any given point in time. Happily, I only worked with those a couple of times before they were replaced with six first-generation Crown DC-300s.
The Yamaha 2200 power amps referenced elsewhere had the greatest "VU" meters ever included in an amplifier, IMHO. I learned a lot about the logarithmic nature of the decibel scale from watching those meters... they even had a scale that indicated power output in watts. Very enlightening for me at the time.