What is the most powerful audio output tube?

Then I can only surmise that you didn't understand what you were seeing.

But still have no idea what you're seeing.

It is.

Irrelevant gibberish.

Irrelevant.

They aren't. You just have no idea what you're talking about.

More irrelevance.

And another steaming pile of it.

You might. But like everything else you've posted, it wouldn't make any sense.

I have a couple of used - but gently treated - EIMAC 4CX3000A tetrodes that I'd be willing to part with. If you're interested, email me with a bid.

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You might consider the 5831:

No, I haven't used them, but the data sheet rates them for Class-B audio use at 370kW per pair!! You'll need a heater supply of 2100A per tube, & the rest > >>

Larkin doesn't endorse anyone. He just plays horse's-ass to keep his name "in the lights".

But then, again, maybe he does endorse krw... Larkin is just as ignorant. ...Jim Thompson

Since the journey is described in terms of distance, speed is of no consequence.

John Fields.

On 01/10/17 23:09, David R Brooks so wittily quipped:

let alone, the size of the output transformer

On Thursday, December 8, 2016 at 10:20:51 AM UTC-5, boomer#...@none.com wro te:

I had MacIntosh MI2OO? amplifiers at one time. They deliverered 200 watts R MS out of two RCA8000 tubes. 940 volts to the plates. I once looked up the RCA8000 and it was not listed as an audio output tube, but that is what was powering the amps. I owned two of them . We would use them for bass guitar or the PA.

I wonder if that guy ever completed the project (post is from 2016.) You can get ~500 watts out of two 813 transmitting tubes in class AB with

But it's probably one of those "if you have to ask you shouldn't be attempting this project in the first place"-projects, even from just a cost perspective I expect the iron alone for just one channel of an amp like that is going to run a couple grand.

Megawatt AM modulators.

Search for some very old medium wave AM transmitters. These had essentially two signal paths, one for the RF carrier power and the other for the audio. These are combined in the huge modulation transformer (tens of kilowatts), so just replace the modulation transformer with an audio output transformer.

You have to go back at least half century, since at least 40 years ago

I think it was Fairchild that used a pair of 4CX250Bs per channel to drive a stereo record-cutting lathe; the cutterhead coil wire was insulated with glass and ceramic.

In terms of wattage against price, the 4CX250B is quite an economical valve to use for audio. You should get 590 watts from a pair in Class AB push-pull with 2kV on the anodes. A 500 watt output transformer is going to be the biggest expense unless you are prepared to wind one yourself.

You will need a blower for the cooling airflow - normally the noise from this would be a nuisance in audio applications, but after a couple of minutes at 500 watts per channel your ears will never again be able to hear anything that quiet.

I'll see your 4CX250B and raise you a 4CX1000A. Two of them operating in class AB1 will produce 3260 watts of audio power. I think they will handle a pair of headphones.

But then there is the 4CX5000, 4CX10000, etc.

The problem with the old transmitting jugs is that they need to run at high plate voltages to make much power. Then the problem becomes, where do you get the output transformer?

Not to mention hundreds of watts of filament power.

But a couple of 833As will impress your friends.