Quote:
Originally Posted by maxhifi
Fair enough, but a pair of 6L6 was usually used in 20-30W amps, for the 10W class there was the 6V6.
And triodes are hard to drive, needing more stages. Triodes in general lost favor over time, even the 2A3 is found in hardly any hifi era products.
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The 2A3 and its variants were used, at least initially. The 6B4G was found in the Sun Radio amps, the 6A5G in the Peerless, the 2A3 in the Brook amplifiers. They weren't terribly common post-1950, but they had adherents. With the popularity of the Williamson, I would hazard a wild ass guess and say that a majority of Hi-Fi amps used between 1947 and say 1953 or 1954 used either triodes or triode strapped beam power tubes.
I'm not going to argue the merits of the triode vs pentode/beam power tube. That is an ongoing battle that has been beaten to death from the dawn of Hi-Fi. I think it is sufficient to say that if the demand of triode output stages didn't exist, hundreds of thousands of Williamsons, with their triode strapped KT66s, 807s, and 6L6s wouldn't have been built. You wouldn't have had articles in Audio Engineering magazine extolling the virtues of the triode strapped 6550s circa 1954. I don't fall into either camp. I think you can build an excellent sounding amp with a pair of 6V6s and a pile of garbage with a pair of 300Bs. The circuit matters far more than the output device of choice.
Sure the 6V6 could do 10 watts in a push pull pair... at 5% THD, with a shitty damping factor, and virtually requiring some sort of negative feedback. A push pull pair of 6L6s could get you ten cleaner watts without much effort. A 6AS7G or pair of 6B4Gs or 6A5Gs could have done even better yet, and with less effort...
There's a reason Paul Klipsch demonstrated his Klipschorn in the early years with a single Brook 12A and not a push pull 6F6 or 6V6 amplifier. It is very easy to build an excellent sounding push pull triode amp. It is much harder to achieve the same level of quality with pentodes/beam power tubes.