Discussion in 'Amps and Cabs [BG]' started by hoodadoo, May 11, 2005.

  1. I finally picked up a Mesa 400 head. I was told the tubes are original, and it would be a good idea to change them soon. The pre amp tubes have already been replaced. My question, what are the best power tubes on the market to use? What make?
  2. I may be giving crappy information, but dont worry about replacing the tubes til one goes microphonic or just plain craps out

    but i supose, if you dont that, gigging with a backup might help
  3. Ralphdaddy

    Ralphdaddy Supporting Member

    Nov 6, 2003
    Chicago, Illinois
    If you're going for a specific sound then changing the tubes might be a good, though expensive, way to change the tone of that amp a bit. Also, is it a 400 or a 400+? Because they use two different types of tubes, the 400 uses 6550's while the 400+ utilizes 6L6's in the power section. I have JJ/Tesla's in my 400+ and I couldn't be happier with them, but I like a midrange heavy, bottom heavy tone with smooth high end that isn't ultra present. It all depends on what you're looking for, if you like it the way it is and it's not making any weird popping or crackling sounds don't bother changing the tubes.
  4. I GOT A MOHAWK, there is that microphonic sound going on, and it would probably be best to match and replace them all. I do have back up amps, but would like to fix this one ASAP.
  5. Ralphdaddy

    Ralphdaddy Supporting Member

    Nov 6, 2003
    Chicago, Illinois
    In that case I highly recommend JJ's, they have a very tight bottom end, good strong midrange and great highs. But there's plenty of good tubes for different things on the market. I just like the way JJ's distort, to me it's a very pleasant distortion.

    oh yeah, Bob at has the best prices I know of on JJ's.

    also check I've ordered from them twice and they have excellent tubes and prices.
  6. Ralphdaddy, it is 400 head, not the 400+. I did call customer service at Mesa, but they are no longer replacing with the original make tubes. I'm getting that slight resonation on certain a loose filament ringing. The more the volume, the more pronounced the "vibration".
  7. Ralphdaddy

    Ralphdaddy Supporting Member

    Nov 6, 2003
    Chicago, Illinois
    Don't bother with Mesa tubes, look into Sovtek's, Ei's, JJ's, Svetlana's, Electro-Harmonix... there's lots of tubes out there, get the best tubes you can afford as the sound quality is usually worth the extra money. But don't rush into it, all the tubes sounds a bit different, even between different production runs of the same tube. Research and make a decision later. You'll need 4 12AX7's and 6 6550's right?

    Oh wow, I just looked at your profile, sorry to come as the teacher, I should be the student here! You've got some nice gear man! How's that B-15, what tubes are in there?
  8. Just the 6 power tubes, the other 4 were recently replaced.
  9. Ralphdaddy

    Ralphdaddy Supporting Member

    Nov 6, 2003
    Chicago, Illinois
    Is it sitting on top of the cabinet without anything in between the head and the cab? If so, throw a blanket in between or put the head on the ground. I did this with my 400+ and it ended that exact problem you're describing.
  10. It's in a rack case, and I do have it on top the cabinet, 2x15's. I'll try your remedy. Thanks. Maybe I should try spell check while I'm at it!
  11. Ralphdaddy

    Ralphdaddy Supporting Member

    Nov 6, 2003
    Chicago, Illinois
    No worries, took me a few days to figure that one out :smug:

    What made you choose the 400 over the 400+? I've always wanted to try a 400 just to see how different it is.
  12. I was looking into getting the 400+, but the idea that Mesa discontinued the 400 head appealed to me. Plus, I'm more primal a bass player. All my other amps are Ampegs, 68 B-15, 67 B-12, and a 250 Posta Bass, with the 2x10 cab.

    It's been a while since I've had something this powerful. Years ago in the 70's I had an SVT with the 8x10's.
  13. Ralphdaddy

    Ralphdaddy Supporting Member

    Nov 6, 2003
    Chicago, Illinois
    Wow... you've had, and still have, some awfully sweet gear. Does it sound different from 400+ or didn't you compare them at all? I'm just intrigued by that amp too, especially since they only made it for like 2-3 years before switching to the 400+. But I'm so broke that there's no hope of affording another new amp.
  14. No, I haven't had the chance to play through a 400+. Aside from the slight extra wattage, I would think the sound would be about the same. Maybe a little more high low range to dial in with the equalizer.
  15. Have you tried gently tapping each of the power tubes with a pencil or your fingernail when the amp is on?

    It is just as likey the pre tubes could be microphonic, sure they are new, but it still happens, and is a s*it lot cheaper to fix!
  16. danomite64


    Nov 16, 2004
    Tampa, Florida
    I had a 400+; it does sound a lot like my 400. I bought a matched set of Elecro-Harmionix 6L6's and the EH 12AX7's, and it works fine. I was told by someone at Mesa that I would get more power if I sued 6550's, but they cost more, are harder to get, and the tone wouldn't be quite as nice as the 6L6's, and frankly, I don't think I'll ever need more power than what it gives me right now.
  17. Psychdave


    Apr 4, 2005
    Valencia, CA
    My 400 has replacement 6L6s in it, generic Chinese relabeled by some outfit. After consulting with Mesa I am going to replace them with 6550s. It is already sounding pretty good but it would be nice to have the extra headroom... don't know why, I am never anywhere near clipping with the 4 x10 SWR and the 2 x15 is just excessive. Mine still needs to be checked on the bench, I think it has been modded to set the bias on the outputs, if not will probably have the tech do that so I can dial the outputs in correctly. There are times I would like it to growl more at low levels, how is yours for getting a touch of distortion at lower levels? I have cranked the preamp and dialed back the master, but it is still quite clean when driven by a Ric.
  18. Masher88

    Masher88 Believe in absurdities and you commit atrocities

    May 7, 2005
    Cleveland, OH
    My Mesa 400+ manual says that it uses (12)5881 power tubes...are they the same as 6L6's or something? Sorry for my ignorance.
  19. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Seweracuse, NY
    Get a new set of matched balanced tubes.

    Power tubes are not preamp tubes and do need to be changed on occasion. Don't go and buy just one tube, go and get a full set of tubes that have been professionally matched and are correct for the set bias that the 400 has.

    My preference is JJ's from Bob at Eurotubes. I do like Ei's but their fail rate out of the box is pretty high...and I don't know if they make the tubes you'll need.

    You have a nice amp.

    Treat it well and do right by it and it will sound great and last long.
  20. I do have an amp guy that does my amp work. He is certified with Fender, and he says to stay away from the cheap tube replacements. I know enough to know you have to replace all the power tubes at the same time, they must be matched, and to have the amp biased. I will bring the amp to him to do, and trust his choice for power tubes. Thanks everyone for the input, it's appreciated. I have a gig tonight, and it will be the first time I'll be playing through the Mesa at a gig. I'll let you know how it went.