Retubing My 2:90 - EL34s?

[darkalone]

Hey everyone. I've played quite a few EL34-powered amps lately, and they all seem to have a more spongy, saturated gain than my TriAxis/2:90 can put out.

I was thinking of trying out some EL34s in my 2:90 to see what kind of difference it makes. Can that be done? Do I need to re-bias?

Thanks for any help.

 

[fpoon]

I'm pretty sure you can. EL34's are great for the crunch sounds I heard. Btw, you from the ESP Forums? They're filled with morons lol.

 

[darkalone]

Yes, I'm from the ESP Forums. It's a brutal and sarcastic place, but once you sift through the who's who, there's no other forum like it. I like to call it home. 8)

Will putting in EL34s require any modding or biasing to my 2:90?

 

[disassembled]

A 290 is nearly a mirror of the Mark IV power section (X 2 of course) so you can put EL34's in the Class A slots of the power amp. It depends on your version of the 290 (old or new) that will determine where the EL34's can go. I have EL's in channel A of my 290 but I have not had a chance to turn the amp up yet to see how it sounds.

Give Mesa a call and they can send you a PDF on where to place your tubes.


Greg

 

[darkalone]

Thanks a lot Greg!

 

[rpdz]

I was thinking about doing the same thing. I spoke to Rich at Mesa on Monday 11/5/07. He said that none of the Mesa techs recommend Using El34's in the 2:90. It was designed fo 6L6 tubes and should be kept that way. He also said to use any type 6L6 tube for retubing as long as you use matched pairs, one on top with its match below it.

 

[disassembled]

I was thinking about doing the same thing. I spoke to Rich at Mesa on Monday 11/5/07. He said that none of the Mesa techs recommend Using El34's in the 2:90. It was designed fo 6L6 tubes and should be kept that way. He also said to use any type 6L6 tube for retubing as long as you use matched pairs, one on top with its match below it.

I think you should get with another employee. There are PDF documents published by Mesa which clearly illustrate how to do it. Electronically the 290 is the same as a Mark IV, minus some features, so then the Mark IV should not use EL34's either.

I've talked to Mesa and the employee said you can use EL34's not sure of his name though.


It's your stuff so if you don't want to use EL34's for whatever reasons then you don't have to.


Greg

 

[rpdz]

I've heard there are PDF's, but I have never seen one. Rich is the customer service rep over at Mesa. He will go out of his way to find answers for you.