Re: Woodstock PA system....
Fascinating that the McIntosh amps used a set of push-pull-parallel 6LQ6 TV "sweep tubes" rather than a couple of big 813-style ones.
Was this perhaps cheaper? Or possibly a nod towards reliability - with four tubes in each half of the push-pull setup you could lose one tube and things would continue (with a bit more distortion) until the end of the set.
(lots of parallel tubes also mean you can trade lower HT volts against higher HT current - 500V at an amp or so is more open-air-rainy-venue-friendly than 2KV at 250mA)
|