Guitarist's amp up and quit

Discussion in 'Amps and Cabs [BG]' started by DelsFan, Dec 31, 2007.


  1. I know this is a bass forum, but figured you guys would know the answer. Our guitarist is playing through his Fender Blues DeVille amp and it just quits. One can now only hear the faint sound of guitar when he plays.

    Is it a 99% probability that he has just blown a power tube? The amp has two 6L6 power tubes and three 12AX7 pre-amp tubes. Any way to tell which side the problem is on? If we had blown a pre-amp tube I'm assuming sound would still come out?

    I'm thinking of just calling Mesa Boogie and having them send me five new high quality tubes - and just looking at this as a good excuse to upgrade the sound/amp.

    Any advice appreciated!
     
  2. First of all why Mesa Boogie?

    Second of all no Mesa Boogie. I prefer to call them Booger Tubes and high quality is the last thing I would use to describe them. They may make nice amps but they can keep their tubes (which they really do not make, they just put their name on them).

    As for the problem, yes it is likely a power tube.

    I have had good luck with JJ power tubes but have never tried their 6L6s.
     
  3. Nighttrain1127

    Nighttrain1127 Supporting Member

    Nov 27, 2004
    Near Worcester MA
    +1 on staying away from Messy I mean Mesa tubes. They are reallly not all that High quality. I have also had good luck with JJ tubes (I got mine from Eurotubes.com). My Mesa 400+ liked them much more than the Mesa tubes. Mesa takes someone elses tubes Ruby, Electro Harmonix ect. and puts their name on them and charges you much more for them than you would pay without the Mesa Name on it.
     
  4. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    It's not at all certain that it's the tubes. It could be the tubes but it could be a number of things. Buying tubes and throwing them in there isn't rhe way to fix it, especially Mesa tubes. You buy Mesa tubes and you just pay $5 more for the name. They're no better than a plain old Sovtek tube you can buy for $9.

    Take it to a tech who knows tube amps and have him fix it right. If you have to change power tubes, you will need to get it rebiased, which has to be done by a tech. It will be probably be cheaper than throwing a whole new set of tubes in it anyway.
     
  5. Thanks for the heads up on Mesa vs JJ... I'm not surprised to be mistaken as I don't know tubes real well, but I feel like someone looking for a stereo, and thinking Bose was good :rolleyes: .

    So, Eurotubes is willing to sell me five JJ tubes for $60, or a little less, whereas Mesa wants $48 for three AX7's plus $32 for the matched pair of 6L6's for a total of $80. And you guys are telling me the JJ's are better? (I'll believe you, just checkin'!)

    From the Eurotubes website - as a person particular about sound (OK, an anal retentive person with an engineering degree) I'm in heaven with the different options presented by someone "with a clue":

    Fender Blues Deluxe-Deville 6L6GC
    Price: 59.50
    Description: A hotter matched pair of the JJ 6L6GC's for the reissue or original fixed bias 90's Blues Deluxe or Deville for a big warm tone along with three JJ ECC83S's with one balanced for the phase inverter in V3. These will reduce the harsh mids, the brittle highs and make the drive channel much more usable.

    Fender Blues Deluxe-Deville Blues Option
    Price: 59.50
    Description: A hotter matched pair of the JJ 6L6GC's for a big warm tone along with a standard ECC83S for V1, an ECC81 for V2 to drop the gain with one balanced ECC83S for the phase inverter in V3. These will reduce the preamp gain for players wanting less gain.

    Fender Blues Deluxe-Deville 6V6 Blues Option
    (This kit will ONLY work in the new reissue Blues Deluxe and Blues Deville amps with adjustable bias!)
    Price: 53.50
    Description: A matched pair of the JJ 6V6's to reduce the power for an earlier breakup along with a standard ECC83S for V1, an ECC81 for V2 to drop the gain with one balanced ECC83S for the phase inverter in V3. These will reduce the preamp gain for players wanting less gain and less power.
    [I'm thinking this is the one for us - as our space is small, the normal volume setting is 2, and we never turn it above 3!]

    "Take it to a tech who knows tube amps and have him fix it right. If you have to change power tubes, you will need to get it rebiased..."

    One of my high school buddies is an experienced tech. I'll have the tubes sent to the shop where he works and let him install and rebias them. I'm thinking this a good opportunity to upgrade the amp for not too much money.


    THANKS for your input and advice ! ! !
     
  6. Dave W

    Dave W Supporting Member

    Mar 1, 2007
    White Plains
    Buying tubes right now without knowing what the problem is just doesn't make any sense. Bring it to a tech and have him check it out first. It could be the transformer, it could be the caps, it could be a bunch of things.
     
  7. elpelotero

    elpelotero

    Jun 16, 2006
    groove tubes are what come standard in a fender. go for those.
     
  8. Steve

    Steve

    Aug 10, 2001
    It's not all that common that a tube goes like that without taking something else with it.

    FWIW I work with a guy that went through 3 of those amps in a row. They all had bizarre issues with the circuit boards. Brand new amps didn't last two weeks onstage.
     
  9. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Pasco, WA
    It could be tubes or it could be an output transformer. The easiest thing to do would be to slap in a set of cheap or even used tubes to see if that is indeed the problem. If so, cool. Get a set of whatever you want and be done with it. If tubes weren't the answer take it to a tech.

    :)

    Joe.
     
  10. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma

    a big step up. "These tubes are hand made in the newly reorganized Tesla factory, recently relocated in the Slovak Republic. JJ Tubes are made on some of the original European equipment that was used in the heyday." -> Tubedepot.com on the JJ tubes

    mesa tubes are just chinese made tubes similar to low end sotek and groove tubes. it took me two years to convince my guitarist that it was ok to use something besides mesa in his amp as long as the pairs were matched, when he finally tried them it made a world of difference.
     
  11. thesteve

    thesteve

    May 28, 2007
    San Diego, CA
    Has he tried other guitars/cables etc.? maybe a dead pedal somewhere in the signal chain?

    BTW, I support the JJs hype. Bob at Eurotubes has been a great guy to deal with.
     
  12. No. No, no, no. Most of the time those are almost as bad as Mesa tubes.
     
  13. thesteve

    thesteve

    May 28, 2007
    San Diego, CA
    indeed...they're the easy/lazy swap if you don't want to have your amp biased and are okay with spending more money for relabeled Sovteks.
     
  14. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Groove Tubes are another relabeler who buys regular Chinese and Russian tubes and puts their label on them and charges you extra.

    But look, don't go buying any tubes yet. Take it to your friend and see what he thinks, THEN buy tubes if you need them. Tubes do quit working, but you might have just one tube out, then you bought a whole set for nothing. Wholesale changing of tubes is useless and a big waste of money. You only buy the tubes you need and you keep the rest. Tubes will last decades sometimes.
     
  15. Why not yank them all out and take them all down to your local electronics store (who deals parts) and test those tubes. It is free and is just like testing the mosfets in a solid state amp. If you do not have a store near by, just go to a local college and find an electronics professor. They should have a tube tester. Can't really beat a known good part.
     
  16. A9X

    A9X

    Dec 27, 2003
    Australia
    Take it to a tech.
     
  17. "FWIW I work with a guy that went through 3 of those amps in a row."
    "Has he tried other guitars/cables etc.? maybe a dead pedal somewhere in the signal chain?"
    [JJ's are] "a big step up."


    My friend called Fender and they said, "It's a tube." However, it sounds like it actually could be something else too. I think the "take it to a tech" advice is good; my first preference is to take it in (to an outhorized dealer) and see if there is something that could be fixed under warranty. The guys live in a small town, so that is a little difficult, and if it is just a tube I'd hate to have to pay them for the tech's time when we can install the tubes ourselves.

    The guitarist doesn't normally use a pedal in our small setup (just the factory footswitch, not in the signal path), and he did try a couple of other cables. He also took the amp to a store (that doesn't do Fender warranty work) and they used a different guitar with the same result. Must be something in the amp.

    Checking the tubes first makes great sense - I'll see if my friend is comfortable taking the tubes out and finding a place that will check them. I'm not averse to buying five new tubes - as my experience with tube pre-amps for my hi-fi system is that new (and better) tubes offers a pretty instant and dramatic upgrade.

    THANKS SO MUCH for the advice. I'll let you know what was the problem, and how much improvement is offered by the JJ's tubes if we go that route.
     
  18. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    If Fender said it's most likely a power tube, I believe them. The thing is, though, if you have to replace power tubes, the amp will need rebiased anyway, and that needs to be done by a tech. You should buy two matched 6L6CG's, then have the amp rebiased. It may be a pain to go drive out to this tech, but rebiasing will prolong the life of the new tubes. And if there's one thing I've learned over the years, replacing tubes by the book is the only way to go. But it's not a difficult or expensive procedure, so maybe you know of a tech that lives closer...?
     
  19. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge

    Oh happy day! Saints be praised - the bass guy finally get's to carry the day! *Hallelujah!



    * that'd be Church o' de Ska - as I oughtta know livin' in Skamania county as I do...
     
  20. island_bassist

    island_bassist

    Jan 1, 2008
    I had that same problem. it turned out to be a blown speaker. but check the tubes as well. your guitarist should have replacement tubes on hand.
     
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