Monstrous 1kW amp!

[bigwill]

Check out this monster, found it on youtube:

YouTube - 1000W Amplifier Philips EL6471 at full power

YouTube - 1kW Philips EL6471 Tube Amplifier from 1955 demonstrates its original sound - listen!

YouTube - 1000W Tube Amplifier Interference Pattern of the MV-Rectifiers

YouTube - 1000W Audio Tube Amplifier Philips EL6471 from 1955

Wouldn't like to breath the air around all those MV rectifiers if they smashed!

[TheGimp]

There is a book on Pete's book page about a 3KW amp. Not much bigger really.

I'm surprised at how many people are actually restoring those monsters.

[SGregory]

Have to admit they have a certain cool factor to them. Alot more interesting to rebuild than the old radios I've done

[Zero Cool]

That is so cool! runs of 3 phase! what a monster! Would love to see/hear a pair in action. Wonder what these were used for in 1955? front end for a transmitter maybe?

[rknize]

I really need a better recording of Widor's Toccata.

[tubelab.com]

I had dreams of a stereo SE amp running about 200 WPC. After firing up a single channel prototype and realizing that I would need to build a vent system to take the heat out of the house, I punted.

Even though my speakers would likely catch fire, I will still build a big amp. Reality has scaled down my definition of "big". My new definition is mandated by the obvious limitation of the American wall outlet. You get 15 amps max at roughly 120 volts per outlet and 20 amps per circuit. That is 1800 watts assuming nothing else big is running on that circuit. So to get 1 KW (500 WPC) you need an amp with a 56% total efficiency. That rules out SE, and makes a 1KW P-P amp unlikely given the power to light the tube heaters. So the definition of "big" gets changed again. OK, my OPT's are rated for 400 watts at 20 Hz so that is the goal.

With this in mind, I have been experimenting to find the best way to use up all of my OPT's power capability. I have seen 200WPC and I am nowhere near done yet!

[rknize]

Well, you could put a 240V dryer outlet in your living room with a 60A breaker. I have one in the garage for the welder. Is 14kW enough? You will need two though...one for the amp and one for the secondary household AC unit to battle the BTUs.

[bigwill]

40 car batteries in series?

[banat]

Tubelab maybe its time to switch to 3 phase wall outlet.In USA(110v) ewerything that exced 500w continous consumpsution must replaced with 3 phase suply(3x200V).Here in Europa (220v)ewerything over 1KW must be replaced with 3 phase main nec(3x380v).BTW many advantages 3 phase primary/3 phase secondary Psu have:Pulsating freqency from full wave rectifier its 360 hz(USA) so smothing fillter is not so critical in comparison with 120 hz from monophase(110v).Comon primary curent is divided in 3,plus primary voltage is not 110v but 3x200v(Primary curent more down)IN extreme cases it is posible to have 3phase primary and 4phase secondary from same transformer.One of the tube which I recomend for High power SE or PP is tetrode QB5/1750(got wery good expirience from high power AM transmitter with this tube).5,6 KV UBA and ower 5KW output with 4 tubes).Or Rusiann big power pentode GU81M.Salute Tubelab

[banat]

The output tubes in Philips EL6471 amp ist actualy 2x QB3,5/750 (very good Transmitter tube)