6l6 tubes

[madmax49]

Does it hurt a Dual Cal. if running 2 different 6L6 tubes? One of my Mesa tube is dead and I don't have time to buy a new set. I'm going to put in a JJ 6L6.

 

[mrd]

You shouldn't put power tubes in that aren't in matched pairs. I don't know if it will actually harm your amp, but in my understanding, running two unmatched power tubes will unbalance the power flow through the amp. Not entirely sure what it will sound like, I've never done it

But there's a reason they sell power tubes in pairs, they are meant to be run that way, and the amp expects it.

 

[>Photi G<]

I'm pretty sure that if you don't run a matched pair of power tubes in your amp, it'll screw up the Output Transformer in some way. Since the two tubes run in push-pull, while one's pushing output, the one is pulling back, so it needs to be well balanced, or you could cause some damage. Single-ended amps can afford to have unmatched tubes, since they are usually Class A wired, running all the time, and if you have a dual single-ended amp, they both feed the OT, and the other tap of the OT is run directly to ground, whereas in a Push-Pull AB amp, one tube is connected to one tap on the OT, and the other tube is connected to the opposite tap.

 

[stokes]

It wont hurt the amp as long as the tube in question isnt running too hot and redplating.It may hurt the sound if the tube is so far off the current draw of the tube it should match.It could cause a slight loss in power and some excess hum.

 

[madmax49]

Guess I'll hold off using the amp till I get a set of replacement tubes.
Thanks.

 

[fishyfishfish]

You can run two different brands as long as the mA is not drastically different between them. Stick with 7-8 mA difference.

 

[MrMarkIII]

When you buy tubes from sellers other than Mesa, you just have to specify what amp you have. As long as your un-matched pair meet this criteria, you won't break anything, but the sound may not be optimum. OTOH, the slight mis-match may actually yield a tone you prefer.