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John Fields John Fields is offline
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Default What is the most powerful audio output tube?

On Thu, 08 Dec 2016 08:59:20 -0800, John Larkin
wrote:

On Thu, 8 Dec 2016 10:39:35 -0500, bitrex
wrote:

On 12/08/2016 10:19 AM, wrote:
What is the most powerful audio output tube, as far as RMS wattage
output?

I have gotten some powerful sound from four 6L6 tubes in push-pull
parallel. but I want more. I know it's possible to use eight 6L6 tubes,
which I believe is called " push-pull parallel - parallel", but I'm
looking into other possible tubes.

At one time, I thought the 807 tube was more powerful than the 6L6, but
after careful research, it's almost identical, but with a different
envelope (plate on the top cap).

I'm looking to get a full 500W RMS (or more) output (per channel), from
all tubes, .... With four 6L6 tubes in PPP, I can only get around 120W
RMS (per channel).


The output tranny required for 500 watts RMS is going to be a huge piece
of ****-off iron that will probably set you back the better part of a
grand, at least.

500 watts RMS from four tubes will require you to step up way beyond
6L6es and 807s, I think. You're probably going to want to look at
something like RF power triodes or tetrodes, 813s or the GU-13 if you're
okay with going ex-Soviet.

I am not a pro tube guy though so that's just my guess.


The transformer is the problem, especially if you go with a giant
transmitting tube that runs at high plate voltages.


---
Which transformer?
---

There have been transformerless audio power amps, using that beast
low-mu triode tube, the one Tek used in their B+ regulators.


---
Which low-mu triode is that?
---

Why not use mosfets? Toobs are silly.


---
But forgiving, and they generally won't give up the ghost until the
cathode's coating is depleted or the envelope melts and the vacuum
sucks it in

JF