Main goal of McI is big power. They use Push Pull mode of tube amps, this mode cause sharp and metal sound, like in more PP brand. PP mode consist in output stage 2 big tubes in two shoulders, upper and down. Signal from preamp fase splitter is divided to 2 /pos. and negat./. Positive goes to upper shoulder and negative - to down shoulder. Every time signal goes from pos. to neg. cross zero, that cause sharp and metal sound. Main + is big power. In mode SE /single end/ signal is not divided and sound is warm!. IMO, I think HiEnd is in mode SE. Power is about 3 - 8 W, but if You use speakers with big sensitivity 94 and more dB, the sound is very loud, and is enough for big rooms, basements.......I listen only SE /my projects/ 2A3RCA, 6S4S, 6P31S, EL11 Telefunken, 300B. I dont like 6L6, EL34 that are used in guitar amps with sharp sound. I advice You look at SE amp and Hi sensitivity speakers.