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Tubes in a Mesa Boogie Bass 400+

Discussion in 'Amps and Cabs [BG]' started by killer B, Feb 8, 2001.

  1. killer B

    killer B

    Apr 18, 2000
    Phoenix, AZ USA
    Hi, I've got a question for anyone who has had a MESA/Boogie BASS 400+ and changed the tubes from the stock Mesa ones. I've heard that Mesa uses cheap tubes and better tubes would yeild a better tone. Now I'm pretty happy with tone as is but I'm curious as to what kind of improvements any of you have noticed with better tubes. Thanks
  2. brewer9


    Jul 5, 2000
    I've heard the same thing about Mesa tubes and am wondering the same thing (sorry I cant answer the question), but I am also wondering if it can damage the head to use non-mesa tubes. They told me when I bought the head that I HAVE TO use mesa tubes because they are the only tubes that are "biased" properly.
  3. killer B

    killer B

    Apr 18, 2000
    Phoenix, AZ USA
    I know that you can use other tubes as long as the bias reisitor is changed by a tech.
  4. Mesa tubes are not the best tubes to buy, and you can absolutely use another source. I have a 400+ and bought my tubes from thetubestore.com. They will ask you to state the
    make and model of your amp and will make shure your tubes are within the specs of what Mesa would use. You do not have to change the bias resistor. The are also CHEAPER by about fifty bucks. I would suggest getting the Svetlana 6L6's, they are a little more but are EXCELLENT tubes IMO.
    These tubes give great bottom end response and the highs are very clear. Hope this helps.

  5. i agree on the svetlanas. i got em and they sound nice........but ive been havin problems with mesa preamp tubes lately and im about to resort to putting in my origional tubes that never failed, i just replaced them w new mesa 12ax7a when i put the svets in. one tube went which caused me to loose channel one another preamp tube went which caused a sound just like a fire alarm in school. ive got a new complementary set of preamp tubes in it now, courtesy mesa, which i suspect problems with, all seemed fine till i gigged with the amp with the new preamp tubes, and i started gettin a mild distortion like buzz, when i brought the rig home the problem went away, i couldnt duplicate it! im gonna push it some more and see what happens but i think my orig 12ax7a tubes are going in. i just ordered a set of jan phillips nos 12ax7aw preamp tubes, i gotta clear this problem up. i am convinced its preamp tubes, as i never had problems till i retubed my amp. im not really sold on the mesa tubes.......
  6. I have a Buster 200, but I know the manual says use MESA/BOOGIE tubes but hey....they are not going to say use the competitors.....As long as they are the same specs I'm chang'n mine.....
  7. spoolie


    Nov 30, 2000
    I retubed my Buster with Svetlanas from www.thetubestore.com. I only had the Mesa tubes in for about 2 months and was disappointed with the headroom the amp had before distortion. This probably is not as big a problem with a 400+ because it has more power but a Buster is pushed to "the edge" more. The Svetlanas cured the problem, I can push the amp louder before breakup and it sounds better across the tonal spectrum. I then changed the driver preamp tube with an Elecro Harmonix 12AX7EH (Sovtek). There was another improvement in tone and headroom but not as significant as with the output tube replacement. In my experience the Mesa tubes that came in my amp were inferior. It's a shame to have to replace brand new tubes to get the most from your amp, however the amp sounds fantastic now. Mesa shouldn't be sending out cheap Chinese tubes in their EXPENSIVE amps. They do very well in most aspects of their business, they should fix this. If you are worried about the Mesa warranty, you can get Svetlanas from Mesa for $48.00 per pair. The tubestore charges $33.00 per pair. I found the tubstore to be very helpful in supplying the appropriate plate voltage tubes and they delivered in 1 day ($12.00 shipping). On a 400+ you could save about $90.00.
  8. OK, how can you tell if you have the Chinese tubes in your Buster? I just bought mine used, and the tubes, while branded Mesa, are not of the Coke bottle variety. Is it possible that the tubes in there are already Svetlena's or Sylvania's?

    The Lord Valve power tube price list mentions something about the D180's originally shipping with Sylvania's. Could this also be true of the Buster, or is it possible that the previous owner already retubed with good ones?

    I've noticed that the STR numbers on the Mesa website seem to indicate tube type. Is this an accurate indicator?
  9. When I bought my 400+ used it still had the original Chinese tubes. When I bought my Svetlana's they where a much larger tube and came with a burnt-orange colored base. I think the " STR " Matthew is referring to is a signature Mesa puts on their tubes and is not an industry designation. Hope this helps.

  10. I actually checked earlier today. The tubes in there are branded STR427, which, according to the Mesa store site, are US equivalent Chinese tubes. Evidently, Mesa has two different kinds of Chinese 6L6's they use. The Coke bottle ones are less expensive by a few dollars.
  11. spoolie


    Nov 30, 2000
    My amp came new with the Chinese ST427s. These were the one's that sounded bad (in my case) and one was actually cracked on the base. I guess I could have had Mesa replace it but didn't think they would send the more expensive Svetlanas and even if they had, I would have still had 4 of the crappy ones. As in the above post, the Svetlanas I bought to replace them had brown-orange bases.
  12. Psycho,

    What is going to be the fundamental difference between the Philips 7581 and the Svetlana 6L6GC? It looks as though thetubestore.com still has some in stock, and they are half the price of the Philips. Supposedly, they can provide the Mesa spec tubes like Lord Valve as well.
  13. Psycho,

    My guitar player has a Mesa .50 Caliber head that uses the exact same tube. Would changing the tubes with the Svets or Philips make any noticable difference in his amp, or is there somehting else that would work better? I'm sure you deal with more than bass amps in your job, so I figured I'd ask.

    FWIW, he doesn't use the overdrive on the amp, but uses a Rat pedal for distortion. Clean power is more important than power sube saturation.

    Thanks again

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