I put EL34's into my Mesa 2:90

[Robert S.]

Yep, I got bored.

I had read on this board a few weeks back that it is possible to put EL34's into the so called class A sockets in a Mesa Simuclass amp. Being the curious sort I did a little research, talked to my tech and confirmed that I wouldn't let the magic smoke out of my amp.

Then I filed the info into the back of my head. I already have a killer sounding Marshall with EL34's so it wasn't all that pressing an issue.

Then I bought a Crate V32 along with a TS9 and gigged on that amp for a few weeks. Big fat mids, chunk to spare and a fat warm clean tone to die for. I got hooked on the mid honk quick.

So I've been looking at the Mesa rack for a couple of weeks wishing I had some of that EL34/EL84 snarl. It just so happens that I have Mesa branded EL34s in the Marshall. I figured what the heck last night and pulled the EL34s out of the Marshall and put them into the 2:90.

Talk about a serious improvement in tone. I now have a Mesa rack that sounds like a Marshall on steroids with killer mids, crunch and definition to die for. My cleans are warmer and almost voxish sounding. I'm going to have to buy 2 pairs of EL34s tomorrow for the 2:90, the Marshall is already biased for the tubes I have and the Mesa doesn't need biasing.

You 2:90 owners need to try this. It really makes the 2:90 sound warmer and smoother and yet more brutal at the same time.

My amp is seriously badass.

 

[Gearjoneser]

Re: I put EL34's into my Mesa 2:90

That's good to know, because Mesas sometimes prefer 6L6's, since the amps were designed around that tube.

 

[JLagoon]

Re: I put EL34's into my Mesa 2:90

Put 4 EL34 and 4 6L6 in your 2:90, I think that it could work that way.

I have a plan to use 2 EL34 and 2 6L6 in stereo on my power amp. Do you guys think that the sound would blend together?

 

[Guitarist]

Re: I put EL34's into my Mesa 2:90

Hot damn! Don't you love Simul-Class?

 

[muttonchopsrule]

Re: I put EL34's into my Mesa 2:90

i've been telling you guys, EL34's in a mesa is where it's at!

good to hear that you're diggin it :beerchug:

 

[DeadSkinSlayer3]

Re: I put EL34's into my Mesa 2:90

Ah very cool! I can't say I liked EL34's in my Recto that much, but I can imagine they'd be killer with a Tri-Axis!

 

[DeadSkinSlayer3]

Re: I put EL34's into my Mesa 2:90

You went back to 6L6's? Oh well, that amp kicked butt with either.

Yeah, only dug the EL34's for about a week... they sound really like...strange, and a bit undefined on the low B. I can't put it into words, it was just weird.

 

[Benjy_26]

Re: I put EL34's into my Mesa 2:90

Robert, can you run a full set of 6L6's on one side and a EL34/6L6 mix in the other side?

 

[Robert S.]

Re: I put EL34's into my Mesa 2:90

Benjy, the answer is yes and no.

The 2:90 is a stereo power amp. Each channel has 2 sets of tubes. One set is wired class AB, the other pair is wired class A. You can swap the 6L6s in the class A sockets to EL34s. You cannot do this (to the best of my knowledge) with the class AB sockets. The 2:90 has 8 power tubes, four across in two rows that are stacked together. Each stack is a pair. This means that the outer stack is a pair, each inner stack is a pair and the last outer stack is a pair.

Its not the same as a Marshall where the inner tubes are matched and the outer tubes are matched.

A B C D
A B C D

The tube layout is as above. You can change the A tubes for a matched set of EL34s and the D tubes as well. A is not matched to D, it is matched to the other A tube.

I'm not sure I'd like all 8 tubes to be EL34s but having 2 pair of both really opened up this amps tone and added a lot of character.

Its seriously worth a try. I rehearsed for 3-4 hours last night and I couldn't put my guitar down. It really does sound that good.

Since I am being somewhat unclear, my 2:90 has both 6L6s AND EL34s in it. The best of both worlds.

 

[Benjy_26]

Re: I put EL34's into my Mesa 2:90

Now I HAVE to get a Simul.



One last question Robert: How much louder is a Simul 90 compared to my 50:50?

 

[Robert S.]

Re: I put EL34's into my Mesa 2:90

Thats another tricky question and the short answer is that I don't know exactly.

The longer and more confusing answer is that a 100 watt amp will be 3 db louder than a simular 50 watt amp. So one side of my 2:90 will be somewhere between 2 and 3 db louder than one side of your 50:50.

The thing is that we both have 2 power amps. Does that mean that I am 3 db louder per side for a total of 4-6 db or is it still a 2-3 db difference.

The truth is that while the 2:90 does have more wattage, neither of us will ever have the chance to play either of them full bore for extended periods of time in a playing situation. I have found that I can get killer tone with plenty of throat and still be at reasonable levels for most playing situations. So if your concern is that the 2:90 will be too loud, it wont be as long as you find your 50:50 manageable. If anything the 2:90 just has a bit more headroom.

It's the Simulclass thing along with the 3 switchable voicings that really make the 2:90 cool.

 

[Robert S.]

Re: I put EL34's into my Mesa 2:90

Ok, I picked ap another set of EL34s and put them into the 2:90 and I put the first set back into my Marshall. I cranked the amp up way past rehearsal levels and hunkered down for some real time ear damage last night.

Freakin brutal. Now I have to tolerate a day full of ear crickets but it was worth it.

 

[Grindspine]

Re: I put EL34's into my Mesa 2:90

Ok, I picked ap another set of EL34s and put them into the 2:90 and I put the first set back into my Marshall. I cranked the amp up way past rehearsal levels and hunkered down for some real time ear damage last night.

Freakin brutal. Now I have to tolerate a day full of ear crickets but it was worth it.

Old thread, but I tried the EL34 2:ninety thing too.

I have tried it too now. The Mesa STR 447 EL34s did add some more grit to the upper mids, so definitely more aggression.

I do think that I prefer the darker gain structure of the Mesa STR 425 (Sovtek 5881 tubes) in the class A slots though. Overall it is a great way to get a tight, aggressive mid sound from a 2:ninety. YMMV.

 

[Boogie Bill]

Re: I put EL34's into my Mesa 2:90

An old thread, but I will add that I use EL34s in the Simul-Class Class A sockets in my Mesa Mark III and IV combos. I can't really put my finger on the change, but whatever it is, I like it. I want to say...more "liquid".

You can use a complete set of EL34s or 6L6s in the Mark V, but you can't mix them; you do not have the option of using EL34s in the Class A sockets with 6L6s in the Class AB sockets as I do with the Mark IIIs and IV. It's too bad, as I really like that sound. But the Mark V has the advantage of 10-watt, 45-watt, or 90-watt output options.

If you have a Mesa Simul-Class amp, I'd highly recommend that you try some Mesa Spec EL34s in the Class A sockets.

Bill

 

[Jeff5]

Re: I put EL34's into my Mesa 2:90

I used to run 6L6 and EL34 in combination in my 2:90 and it sounded phenomenal.

 

[dystrust]

Re: I put EL34's into my Mesa 2:90

I used to run 6L6 and EL34 in combination in my 2:90 and it sounded phenomenal.

+1

For me it was a Simul 395, but EL-34s in the Class A sockets was magic. If I ever build another rack, I'll have to track down a 395 for the power amp.