austin armstrong 409c

Afraid no date sheet I'm not so sure there were any when these amps were first built
The 414c I think was 490 per channel at 4ohms and the 409 300 per channel also into 4 4ohms.
These amps are not 2ohm stable so don't be tempted to try it.
The person to speak to about these amps is Richard or Monitec as he's known as a member on speaker plans as he was one of the original people involved with Austin armstron/Monitec (both the same company basicly)

http://forum.speakerplans.com/member_profile.asp?PF=3336

Edited by colint - 26 March 2017 at 3:22pm

Hi, yes I know quite a bit on Austin Armstrong Amps. I was at school (Cambridge Grammar School for Boys) with the late Dave Collins and I designed the original C Audio logo for him back in the day after he had started Chesterton Audio and MM. I did all the graphic design for C Audio and carried on designing for them even when Harmon took over (I had also for years designed for Mike Harrisonand Hazel Simpson HH, HIT and HEL material as well as Neve). After his C Audio days (that's a whole War and Peace size book story...) Dave started Monitech that morphed into Austin Armstrong. I did all the Graphic Design for both those companies. I still have a 4 channel Austin Armstrong 2400 that has behaved impeccably. I sometimes used it to drive 4 x Bose 802s with the MkII Bose equaliser and 2 x Celstion SR4s... each channel pumping into 4ohms... I seem to recall we beefed up the fans and I had a temp control circuit that could be switched on and off for the fans.