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IS my Sunn 300t busted?

Discussion in 'Amps and Cabs [BG]' started by jow83, Oct 27, 2005.


  1. jow83

    jow83

    Jun 3, 2005
    Sydney, Australia
    Hey guys. Tonight my Sunn 300t i have had for about 3 months started messing up! It has been a really hot day in syd (warmest day since i got the amp) - i was played it for about an hour tonight (just into a quad) and it was working fine, flipped it on standby and went to get a drink and them i come back up and flip the switch back over and it was very distorted, i doubled checked and yes I was still on ch1 - hadn't bumped the footswitch or anything. Not only was it distorted but was not very loud (master on 2, ch 1 gain on 4) and when i was not playing it was making a loud hum.

    A closer inspection of the amp reveals that one out of every 2 tubes (the right hand one in each set) is glowing very bright while the other one hardly seems to be glowing at all. Lights on back of amp are green.

    Tell me this thing is not dead?

    Any suggestions?

    :crying:
     
  2. protoz

    protoz

    Nov 30, 2000
    Iowa
    Yes, send it to me and I will dispose of it accordingly :)

    I would just take it to a tech and see what he says. It sounds like what my Sunn sounds like when I turn it off and accidentally hit the strings so it's may be that it didn't come out of standby all the way for one reason or another (transformer?)
     
  3. johnbegone

    johnbegone

    Sep 16, 2004
    Chicago, IL
    Hmm, take it into a tech. It doesn't sound *too* serious though. I'm not a tech, but I've had this problem with other tube amps and it was solved by replacing the tubes. Could be different for you, but if you've got a good trusted tube amp tech, then go for it.

    -john
     
  4. Get an amp tech to check it out, did you have it checked out when you first got it?

    I should have done that with mine, but almost sodded it all up by using it with a completelly dead 6550 for a while and not knowing what was wrong, hope it aint anything worse than a bias tweak or a set of new tubes :)
     
  5. jow83

    jow83

    Jun 3, 2005
    Sydney, Australia
    I hope its not too expensive to fix, i don't have the cash right now - will in a month tho.

    Is it possible this is just an overheating problem?

    Would you guys recomend not trying to play it until i get it looked at?

    I forgot to mention that it the amp got VERY hot - the off switch on the back was quite hot when i went to turn it off (has never happened before)

    Any of you sydney guys know a good tech?

    :(
     
  6. jow83

    jow83

    Jun 3, 2005
    Sydney, Australia
    bump :(
     
  7. Plain Old Me

    Plain Old Me

    Dec 14, 2004
    Don't play it, it could damage it even worse. If you think its a heating problem (which it could be but isn't too likely) turn it on but only for a few seconds. Just to see if it sounds normal. If not, take it to a tech. It could be a busted tube or filter cap or some such problem.
     
  8. jow83

    jow83

    Jun 3, 2005
    Sydney, Australia
    K will check it out tonight to see if was heating problem, then either way take too tech, now i jsut have to find a good one.

    Any suggestions for replacement power tubes if i need to replace them? Or should I just have the tech put whatever hes got in (im thinking not).
     
  9. protoz

    protoz

    Nov 30, 2000
    Iowa
    Match set of JJ's and that should sound great