60 watt tubeamp with Low B+

[tyu]

From 6moons

The reason the Gennis I60 runs so cool is that I only run the [plate voltage of the KT88s at around 200V.]





Can some one tell Us with 200B+V how I can get a tube amp With two tube say Kt88s pr ch.putout 60watts?

Thanks

[Tom Bavis]

You can't with KT88s. E130L would do better - but a pair needs 300V to do 60W.

[SY]

Originally Posted by tyu

Can some one tell Us with 200B+V how I can get a tube amp With two tube say Kt88s pr ch.putout 60watts?

Find a gullible reviewer.

[smoking-amp]

Looks like it would take the largest sweep tube to do it. A 6LW6 pair into a 1 K Ohm P-P OT would just do it on 200V B+, likely requiring some class AB2 grid current drives. You need that big 400 mA max DC spec of the 6LW6 to meet the average current. Running at low B+ is inefficient, the tubes will run hot, the screen grids will be hot, and the distortion will be high. (Maybe the amp in question has some Mosfets under the cover? Or it's using sweep tubes with screen grid drive maybe? Although I would think screen grid drive would be dangerous for the health of the tubes with low B+)

[SY]

Nope, the pictures in the review make it clear that it's a very conventional p-p KT88 amp. So there's either mis-communication, fabulation, ignorance, or a combination thereof.

I don't take much in audio review magazines seriously, but of all of them, 6 Moons is the one to take least seriously. Their standards are, to be kind, pitiful.

[aardvarkash10]

you are very harsh SY. I prefer to read 6 Moons as the audio equivalent of The Onion - satire dressed as serious.

[SY]

I hadn't thought about it that way, but you may be right.

[toprepairman]

Could be 60 Watts peak? (30 W rms.)

[SY]

With a single pair of KT88, you'd be lucky to get 15. Legally, a 60W amp has to be able to make 60W average, not peak.

[Serge66]

Hi All,

I have never liked 6moons. It is not a review they write, it's more like poetry.
And some reviewers look like old hippies. They rave on and on and on.....
Serge