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Mesa Bass 400 owners - favorite budget output tubes?

Discussion in 'Amps and Cabs [BG]' started by christw, Dec 31, 2011.


  1. christw

    christw Get low!

    May 11, 2008
    Dayton OH
    I want to be Tesla (tinkerer at Dayton Amp Co)
    Now, I'm not in much of a position to go and buy some fancy schmancy output tubes for this here amp that I just acquired but I wish I was. ;) In that spirit, what would you guys recommend to me as your favorite pick for output tubes for this amp and why? KT88, 6550, what make? I'm assuming that we're limited by transformer size and current draw as this feels like a 45 lb amp so I'm not expecting to pull any extra power from an amp for once.
     
  2. Dennis Kong

    Dennis Kong Supporting Member

    Sep 1, 2004
    San Mateo CA
    Try the reissue Genalex Kt88's. I use those.
     
  3. christw

    christw Get low!

    May 11, 2008
    Dayton OH
    I want to be Tesla (tinkerer at Dayton Amp Co)
    Gah! I'd never delved into the marketing crap that surrounds buying tubes new! Just trying to find factual (not opinion or marketing) info on tubes can be a pain. :eek:
     
  4. someparts

    someparts

    Nov 22, 2010
    Ohio
    Hey Chris, whatever brand you decide on keep the cost down....so in a month when it's for sale I can buy it. :D
     
  5. christw

    christw Get low!

    May 11, 2008
    Dayton OH
    I want to be Tesla (tinkerer at Dayton Amp Co)
    I go through amps like candy, don't I? :D

    I think you'll find it hard to convince me to get rid of a "300w" (though currently loaded with a sextet of stock Mesa 6L6) tube amp weighing in at a cool 45 lbs shy of having a more powerful tube amp in front of me.
     
  6. KT88/6550's may cook your power trans as the heater current is much higher!
    JJ offers some decent tubes at moderate pricing. SED "Winged C" is the top IME but are more expensive. Stay with the 6L6 family of tubes, can remember the current draw of the KT66 or I would say that is an option.
     
  7. christw

    christw Get low!

    May 11, 2008
    Dayton OH
    I want to be Tesla (tinkerer at Dayton Amp Co)
  8. christw

    christw Get low!

    May 11, 2008
    Dayton OH
    I want to be Tesla (tinkerer at Dayton Amp Co)
    The best prices I seem to find are on EHX and Sovtek followed closely by JJ and Tung Sol, as usual. :meh:

    Well, poo. I forgot how costly a retube can be!
     
  9. someparts

    someparts

    Nov 22, 2010
    Ohio
    From what I remember on those you can use just about any 6L6 - but you should do some research on 6550s for sure, as some draw more than others I think. I thought there was no difference in the 6 tube 400s other than the tubes themselves and maybe how the bias was set.

    Only one thing worse than buying a matched sextet of 6550s, and that's losing one due to bias issues...and you have fixed bias there so you want to be sure with the 6550s as that's running the amp at the top of its rated power. Is it true that Mesa no longers sells their spec of 6550s? Weren't they just middle of the road on the matching specs?
     
  10. christw

    christw Get low!

    May 11, 2008
    Dayton OH
    I want to be Tesla (tinkerer at Dayton Amp Co)
    I do believe Mesa set their bias to be quite safe and middle of the road and sold tubes to fit. I never took running only Mesa tubes in a Mesa seriously. From what I've read, it should be just fine running 6550 stock. I'd assume that's the case as it appears to be running it's original Mesa tubes. I'm not looking for anything spectacular, but I think a set of JJ 6550 or KT88 are a safe bet from what I can find.
     
  11. Had jjkt88s in mine, as well as jj, sovtek, mesa 6l6s.

    The jj 6l6s sounded a bit thinner than the sovteks or mesas. Not a big difference between the sovs and mesas from what I could tell. Used the sovteks longer, sold a 400+ and wanted it to have afull set of Mesas so they went with it. With 6l6s the amp was a fuzzrocious beast at loud volumes. Beautiful and terrifying.

    With the kt88s it was much like a 400+, did not break up nearly as easily and when it did it was not so pleasant. Did sound a bit fuller than with any of the 6l6s. I've liked sovtek power tubes, havent tried their 6550 though. wouldn't buy jjs again unless I could get them at the same or cheaper price as Sovteks, and from someone who is not Bob at eurotubes. I don't like having to buy 7 tubes to get 6 that work, and I know plenty of people that will insult me for free, no need to pay Bob to do that.
     
  12. What went wrong?
     
  13. First time, Bob forgot to send me one of the preamp tubes I needed to retube an amp. At that time, I was retubing ALL of my amps with JJs, from his store, and had ordered some for a buddy, over $700. Had to twist his arm to get the missing tube.

    Next order, new amp to retube. JJKT88s - I don't know if they have KT88 and 6550 models now, at the time there was just the one tube sold to be used as either. I did not look them over as closely as I should have, or I may have caught the physical defect. Put them in, turned on the amp, and one of the Kt88s turned into a snowglobe. Looking closely at it I noticed the bottle was at an angle vs the metal base. No problem, or so I thought, I'd read they were warrantied.

    Turns out they were only warrantied until Bob put them in the box to ship, I guess. Accused me of trying to scam him. Out of one tube? after spending $1000 on his tubes? That's not a very profitable scam. Maybe I caught him at a bad time. For all I know his wife had to be put down for rabies the day after his dog left him for the plumber or something.

    Any product will have a percentage of defects. I don't really hold that against JJ. The rest of the tubes, even the surviving 3 matched plus the 1 replacement I bought from Triode, have been working well for years of sporadic usage.
     
  14. christw

    christw Get low!

    May 11, 2008
    Dayton OH
    I want to be Tesla (tinkerer at Dayton Amp Co)
    So JJ's probably wouldn't be a bad choice. Now I just need to save up $200...
     

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