Pulling 2 power tubes

[puma_21]

Does pulling two tubes from the power section actually do anything besides earlier breakup and a tad less volume and headroom? Does anyone else find it changes the tonal quality?

[HTH AMPS]

You'll need to knock the impedance on the amp down a notch too to retain the correct primary Z.

The tone does change a little, depends on the amp - some more than others.

[Toe-Knee]

HTH is correct.

I find the pulling two valves to be quite redundant though. You don't really get any benefits volumewise.

The only time I ever do it is if I have some valves and one goes bad and then its only until replacements arrive.

[richard]

I remember reading a very convincing article about why this is not a good idea and doesn't actually accomplish what it's supposed to. Something to do with the transformer being designed to work with a specific tube complement. But no harm in trying it - let is know what you think.

[Toe-Knee]

If you adjust the amps impedance it works fine as HTH said the primary Z is then correct.

Oh yeah don't ever do it on a bugera.

A friend did it and it took his OT out in less than half an hour.

[Frank]

The really important specification for the output transformer is the impedance ratio. Your OT doesn't particularly care if it's connected to two EL34's or four 6L6's or sixteen EL84's on the primary - as long as the speaker load on the secondary multiplied by the impedance ratio of the transformer roughly equals the required load for the output tubes then it's all the same from the point of view of those pesky little electrons.

EDIT: except in a Bugera, apparently!