What's the highest power amp you've built?

[esorcc]

Just curious. I wanting to jump into building some amps but my main target will be for sound reinforcement applications so I'll be mainly interested in high-power amps.

[lineup]

Originally posted by esorcc

What's the highest power amp you've built?

My highest amplifier ever
is my own medium power Class AB.
Including power supply and everything
the height is almost 30 cm ( ~1 foot )
Because it is more built to be high, than wide,
the heatsinks will have a more optimal area of cooling.

This is my highest, so far.
But who knows what may come soon ......

[Nelson Pass]

4 KW

[lineup]

Originally posted by Nelson Pass
4 KW

Woow, Nelson

Was it maybe like a little bit hot in your testing room?

[john curl]

Nelson, your amp is bigger than mine. I only did 2KW.

[Cloth Ears]

Originally posted by Nelson Pass
4 KW

Uh... to drive an arc-welder ?

[georgehifi]

This isn't wattage, but maybe the highest pure class A, it was loosely based on Nelson Pass's 20watt Class A from 1977.
It was biased up to 150pure class A, then 300AB
8kva dual secondary transformer,
500,000 filter caps per channel with a further 50,000uf bypassing ever decreaseing down value to .47uf plastic.
24 Hirel outputs per channel (pnp eb204 npn ed ?) for memory they were 20amp 200watt 20mhz continuous each. what ever happended to these magnificent tranies
The system had a huge milled heatsink with 4 tunnels lenghtways and water was serpentined through to a quiet water pump, then to and parralel flow airconditioner radiator which was fan cooled with a Garrad turntable motor attached to a Davis Craig automotive 17" plastic fan which cooled the water (coolant) flowing through the radiator, a thermometer was used to monitor the water temp which was held at around 110F.
For memory the amp (which was a two man lift) took some 15amps continous from the 240v mains (special mains socketts were mandatory).
When switched on this amp physicaly moved the mains wire that came from the street the the house upwards about 2".
I built another four of these after that but used the house water to feed the heatsink instead of the pump radiator setup, the excess hot water was fed to the outside which eventually watered the garden.

That was a few my amps that I built from the late 70's
Unfortunatly not a single photo of them, but may gobsmacked wittneses in Australia Allen Wright being one of them.

Cheers George

[georgehifi]

This amp drove maybe an even more bizarre system,
A pair of Otto Major/Chris Feillafe (improved mid/high panel) double stacked 57 quads
A pair of Decca Kelly ribbons xover at 12k
Two 36’ Hartley subs 15hzfo xrossed at 100hz mounted in the double brick wall using the adjoining room as sealed speaker boxes
The front end was a Stax tube electrostatic cartridge, which took 1 hour to tune in using an oscilloscope and remained in tune for about 20mins then had to be retuned again.
This was in a early Lin, Black Widow arm setup my pre/riaa then into my Lightspeed Attenuator volume control.
With this amp and system the sound still has not been bettered even today say those who heard it.

Cheers George

[lndm]

Originally posted by Cloth Ears
an arc-welder ?

AKA plasma woofer anyone?

[lineup]

Originally posted by john curl
Nelson, your amp is bigger than mine. I only did 2KW.

And here is Nelson and his assistent
setting up the filter caps
for the 4.000 Watt amplifier