I doubt anyone has built one of these amps without reading mauldroppers. The only reason I posted it here is because the link was broken there for some time and maybe still is for all I know. But we all know with the demise of the 2sc2879 these plans are almost obsolete now. There are more competitively priced and reliable parts available per watt which is what most manufacturers are using. I guess we both take it for granted that whoever uses these knows what they're doing, does their research and not to build anything larger than a 4 pill due to mismatches from a lack of test equipment usage blowing transistors.