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Peavey Classic 400 help!

Discussion in 'Amps and Cabs [BG]' started by myke.nytemare, Dec 21, 2006.

  1. Hey,

    Just got the Classic 400 I bought and it seems real awesome and heavy, but I got a little problem and do not feel like I should even plug it in and power it up.

    After I unpacked it, I saw that the Original Peavey coke bottle tubes had not been removed (which I had requested before and when I sent payment) and all of them have a slight rattle and two have a bad rattle (the two bad ones where not in their sockets and were rolling around the inside of the amp). My questions are as follows:

    *Do all tubes have a slight rattle?
    *Will turning on the amp without a full set of working tubes damage it (ex: I leave the rattling tubes in and power up the amp anyways to try it out)?
    *Can I just replace the bad tubes and use the head the way it is until I have the cash to get a full setup/biasing/new tubes?
    *It seems as if the "copper foil" slightly lifted off of the rest of the "transformer" inside the amp....a picture with the area circled is in the next post... IS THIS SOMETHING THAT I NEED TO WORRY ABOUT TOO?

    Please help me...I think I may have bitten off a little more than I could chew with this tube monster. Help me to get it up and running so I can at least try it to make sure it works ok.

    Attached Files:

  2. Here is the pic of where the foil has lifted off of the transformer area (at least I think its the transformer/power supply)

    Attached Files:

  3. scotch

    scotch It's not rocket science! Supporting Member

    Nov 12, 2006
    Albany, NY USA
    Please see Profile for Endorsement disclosures
    Hey. I own 4 different tube amps & while I'm no expert, I have never had a power tube that rattled! I do know from experience that a bad tube can hurt your amp. I had a bad 6550 in a 300 watt fender head that got so hot it wrecked the pc board it was mounted to. For something that big & expensive - take it to a good tech first & see if the person who sold it to you will do the right thing & help you out w/ some new tubes.
  4. BbbyBld


    Oct 13, 2005
    Meridian, MS
    The copper is just a shield. It sometimes comes loose a little. I wouldn't worry about that.

    It's normal for power tubes to rattle a little. Tubes are pretty durable, so if the glass is not broken or there are no pieces broken off inside you may be ok.

    I think you should put all of the tubes back in it and let it warm up on standby for 5 minutes. Hook up a speaker cab. Make sure all of the filaments are lit. Turn the lights off in the room and flip up the standby switch while you watch the power tubes--this will help you see the plates. Keep your hand on the power switch while you watch the power tubes. If you see arcing or hear any loud popping, or see the plates start to glow red, shut the power off. Keep an eye on the amp for a few minutes, and if it survives you're probably ok.
  5. Thanks BbbyBld....try it tomorrow when my band jams....still want that new 225 watt tube bass head for home/studio use when it comes out early next year!
  6. BbbyBld


    Oct 13, 2005
    Meridian, MS
    If those two tubes rattle bad, you can leave them out if you wanna play it safe. Do it like this looking from the front.

    X O O O
    X O O O
  7. Eric Cioe

    Eric Cioe

    Jun 4, 2001
    Missoula, MT
    Huh? When did this happen?
  8. The 0x

    The 0x

    Aug 24, 2003
    Timonium, MD
    Yeah, huh?!? :eyebrow::hyper:
  9. James Hart

    James Hart

    Feb 1, 2002
    Endorsing Artist: see profile
    :eek: I'll preorder one now!
  10. Espidog


    May 19, 2006
    Yeah, spill the beans. Whose 225 Watt all-tube bass head? Peavey?
  11. I used to own a Peavey Classic 400 just like that. It should have a total of 14 tubes. You should have the 8 6550 tubes and 6 preamp tubes for the 2 preamp sections. As far as a rattle, sometimes this is not abnormal for a tube. I would have a technician check the tubes before you reinstall them and power the unit up. As far as your question of running fewer tubes. Yes, you can do that but I wouldn't. I liked the headroom this amp provides with ALL of them. It is configured in a push pull wiring design which means that 2 6550's work together as a common pair producing 100 watts per pair. Each successive pair adds another 100 watts to the output for your total of 400 watts. It is possible to use as few as one pair of tubes for the finals, however with that amp it would be a shame to. GREAT FIND!! Other than the weight that is one KILLER amp. I thought mine sounded better than SVT's I had owned.
  12. Peavey had the new tube bass head at their booth at the Bass Player Live event in NYC in October...it should be released in a few months. There is a pic at http://davidellefson.com/News/NewsList.aspx?i=61

    But lets not get off topic. Is the general consensus that I should not run the head without getting it looked at by a tech. After checking it again last night, I realized that one of the tubes is busted (the base has seperated from the glass).

    Should I run it with 6 power tubes just to try it since I do not have a full set of 8 to work with?
  13. Espidog


    May 19, 2006
    You could get by with just 6 output tubes, but using fewer than the full quota will cause the wrong impedance to be reflected to the output transformer and speakers. While not exactly fatal, this is not a situation you would want to maintain for any length of time. The sooner you an get the amp running with 8 healthy tubes, the better.
  14. BbbyBld


    Oct 13, 2005
    Meridian, MS
    Yes, that will be fine.
  15. Thanks guys...especially BbbyBld...will check it out with 6 just to make sure it works then off to the tech after new years for some JJ tubes and a setup.

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