software

Hello,
I have a question for the Tube Gurus.
I have a Mesa Mark IV with the EV Black Shadow Speaker, I am getting ready to change out the tubes as I have no idea how long they've been there and it gets some good use.
Anyhow when I purchased the amp used it had 2 Mesa 6L6 tubes and 2 EL34 tubes. I kind of like this combo, but have never heard the amp in it's original config with all 4 6L6's.
Anyhow I kind of want the best of both worlds, I play mostly on the clean channel. But I do love the overdrive channels and kind of wish they broke up a little earlier.
The question is, what kind of tube should I replace the Stock Mesa tubes with?
Please Help.
Louis

Anyone???

You have a Mark IV that has 2 EL-34's and 2 6L6's? Hmmmm. They should be 4 6L6's. Has someone mod'ed that amp?

As to your question, I usually use Boogie tubes, 5881's currently (no pun intended).

My buddy has the same amp and uses all 6L6's. That's the way to go for that amp. You get the true tone of it that way. And it sounds damn good.


Originally Posted by HamerPlyrYou have a Mark IV that has 2 EL-34's and 2 6L6's? Hmmmm. They should be 4 6L6's. Has someone mod'ed that amp?

Mark IV's are wired for Simul-Class, so you can run 2 EL-34's in the outer sockets in pseudo Class-A mode. I think it sounds best with the mix of EL-34's and 6L6's (yes, I tried it with all 6L6's).

To answer the original question, I'd replace the EL's with Ruby EL-34BSTR's and the 6L6's with JJ's. Personally, I'd also change out all the 12AX7's for 9th gen Chinese tubes (maybe a 12AT7 for the reverb driver). I used those in my Mark IV when I had it, and they sounded awesome.


Originally Posted by mridMark IV's are wired for Simul-Class, so you can run 2 EL-34's in the outer sockets in pseudo Class-A mode. I think it sounds best with the mix of EL-34's and 6L6's (yes, I tried it with all 6L6's).

Oh, yeah. You're absolutely right, I. I forgot about the Simul-Class. They come loaded with 6L6's, and I always preferred them in that amp. Thanks for the reminder.

guys at the gear page eat this stuff up too .. you might get some good insights over there as well ... from : localhost/www.thegearpage.net/board/

I'd probably get JJ 6L6's and do what MRID said about the pre tubes, go with the Chinese (GT12AX7C). Contact Todd at and you could either have him ship you the tubes, or you could even pick them up down in Culver City/WLA off Venice/Overland. You probably should change all the tubes, but you may be able to get away with just changing the power tubes and 2 pre tubes.
Ask him for either the GT12AX7C's or the new Tungsols he carries now. All the tubes I mentioned will blow away the ones in there now, and you'll be very happy when you hear it. It'll be louder and tighter sounding.

Well, I replaced all the 12AX7's first with all Groove Tubes, but had a bunch of microphonics problems. The tone was a bit nicer than stock. I then replaced them all with NOS RCA's and the tone got nice and round for a Boogie. That's been a few years ago. My next idea is to replace just the first 12AX7 with a Mullard and see where that get's me, but that's not as hgh up on the list as replacing the power tubes.

Brett

Right now in my MKIV i have a pair of Tung Sol 5881's and a pair of Phillips 7581's both are of the 6L6 family. Like this the amp is very big and warm sounding but has a tighter bottom end. With EL34's it does dirty up quicker in the midrange and have more snarl but the bottom end seems to get kinda loose. I like that sound better for blues and classic rock. In the preamp I have one Mullard and the rest are 9th gen chinese. Honestly if it was me I would buy a quartet of 6L6's and a pair of EL34's so you can expieriment with the different sounds. I've had good luck with the Svetlana EL34's which are now called SED... Also Mesa sells Siemens EL34's under their own name and they are killer also. I do have reservations about using JJ's in a combo MkIV everytime I have tried this in the past the life has been fairly short it seems like the JJ's dont like the extra vibration that comes with being in a combo amp. Just my 10 cents

For me I use all JJ 6L6's, and all JJ 12ax7 hi-gain Ec83s'.

They came with the amp when I got em. Cant be bothered changing em yet.Check the link in my sig, theres some pretty different tube mixes for mark IV's in a discussion at the moment.