Handwired AC15 problems and tube recommendations

Discussion in 'Amps and Cabs' started by Raccoon, Feb 22, 2012.

  1. Raccoon

    Raccoon Active Member

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    Now I'm almost certain that my problem is the powertubes going bad.. but.. I'm really no expert. I've been getting a lot of static/popping noises at random lately and just today I noticed my amp is significantly quieter... especially after it heats up for a while. I opened up that amp and noticed one of my tubes is growing a really bright red (never used to do that.) Anyway.. tube problems or something worse?

    So what should I get for tubes. I really loved the way this amp sounds.. so maybe I should get some more stock ruby tubes? Or maybe it will sound better with.. different tubes?

    I heard the jj's are good.. they've always sounded good to me in the other amps. I thought about maybe getting some JJ's for the preamp and mullards for the power. Also I noticed there are two preamp tubes labled high-gain... so.. should I look for highgain preamp tubes to replace it or does that matter?

    I'm not looking for the classic vox tone.. in fact I like the greenback more than the blue's.. I'm just looking for a really nice sound. I also don't want anymore gain.. less gain is fine.. just no more gain.
     
  2. Blue Strat

    Blue Strat Member

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    No one can say for sure if the problem is tubes. The way to find out is try new tubes and see if the problem goes away. Worst case, you'll have a spare set of tubes which you'll need within a year anyway.

    Ruby doesn't make tubes. They rebrand common tubes on the market today. What you have may be JJ's with Ruby labels on them.
     
  3. Raccoon

    Raccoon Active Member

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    That's what I assumed.
     
  4. Gretsch&Vox

    Gretsch&Vox Member

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    I use JJ ECC803 (low gain, as opposed to the ECC83 high gain) preamp tubes, matched JJ EL84 power tubes and a JJ EZ81 rectifier tube.
     
  5. Raccoon

    Raccoon Active Member

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    Whats the tonal differences between the two?
     
  6. Gretsch&Vox

    Gretsch&Vox Member

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    The low gain, to me, sound brilliant, round and rich. The high gain have more punch but are "mushier" sounding.
     
  7. Raccoon

    Raccoon Active Member

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    That doesn't sound bad at all..
     
  8. sportoflife

    sportoflife Member

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    I had the exact same problem with my ac15h1tv and I just replaced the power tubes with a matched pair of MULLARDS and I have never looked back

    Hope your vox is up and running properly soon!
     
  9. Raccoon

    Raccoon Active Member

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    I remember reading somewhere that the tubes that vox ships in their amps are crap.. so hopefully that's true.

    I hope it's up and running too.. I love my amp... :(
     
  10. Nork

    Nork Member

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    JJ's are a really decent reliable brand and might be a good place to start. They're purportedly "darker" sounding then some tubes. I run JJ's in the power section and TS's in the pre's on my TT and I played it against a buddy of mine's AC15C1 and they sounded remarkably similar.

    Look into whether or not you need to bias the amp with tube swaps, too.
     
  11. mAx___

    mAx___ Member

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    No need, these amps are cathode-biased.
     
  12. Raccoon

    Raccoon Active Member

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    I think I'm just gonna go with a couple jj's for the power at first.

    Think I should mess with the rectifier as well... how often do those things go bad.. as much as the power tubes?

    I really like the way the amp sounds now.. so I'm just thinking about leaving the preamps in for now for good measure.. I don't want to mess too much of a good thing up.
     
  13. Gearaddict

    Gearaddict Member

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    Preamps are cheap, rectifiers a little more....I'd do the whole thing if it is your first re-tube for this amp.
     
  14. Raccoon

    Raccoon Active Member

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    Why?

    What I'm getting at is.. why change it if I already like it? Obviously I don't have a choice with the powertubes though.
     
  15. Crowder

    Crowder Dang Twangler Silver Supporting Member

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    While you're messing with the tubes, you might check the contacts in the tube sockets and make sure they're adjusted properly so that each contact grips the appropriate tube pin correctly. They can get bent through use, but they can even be "not quite right" upon manufacture. It's easy to check and fix. Just use a small flat screwdriver to push the spring-metal contacts toward the middle of each of the holes that the pins seat in.
     
  16. Raccoon

    Raccoon Active Member

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    Good tip... do you think the static or crackling noise could be caused by that?
     
  17. sportoflife

    sportoflife Member

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    I agree! I noticed a big difference from the stock power tubes, however im still running the stock preamp im feeling they are about to be replaced

    90% of my amp problems have been from tubes, they are temperamental things but they are just great!

    I would recommend switching out all the tubes and used the stock ones as a spare set in a pinch
     
  18. Jon@Home

    Jon@Home Member

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    Go with some JJ power tubes. I got some for my 65 ac100 and they are still going strong and sounding good 4 years later. 2 thumbs up.
     
  19. Raccoon

    Raccoon Active Member

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    4 years.. that's impressive..

    I guess most the stock preamp tubes in the ac15hw1 are just relabeled jjs upon further investigation. Seems weird to me that they decided to get decent preamp tubes but crap out on the power tubes.
     
  20. whitepapagold

    whitepapagold Member

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    That would depend 100% on how many hours the amp is played. Tubes have no shelf life- only usage life.

    The tubes with the best usage life are NOS. By far. In the end, for the money, the NOS tubes usually last MUCH longer as well as sounding better.

    But JJs are decent new tubes. And you can get some decent ones that last. And they are wayyyyyyy cheaper.

    I use JJs in my cheaper amps- like my egnater rebel 20, and NOS in my vintage tweed Fenders and JMI 15/4. If the amp was top dollar, I think the tubes should be too. If not, then it won't make as much difference.
     

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