High pitched whine from Tube Amp

Discussion in 'Audio Hardware' started by Paul K, Jan 26, 2004.

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  1. Paul K

    Paul K Senior Member Thread Starter

    Location:
    Toronto, Canada
    Hey kids, tubes are whining - not through the speakers but at the source. What gives? I think it is the power tubes. They are EL34's.
     
  2. Steve Hoffman

    Steve Hoffman Your host Your Host

    Determine which speaker is whining, right or left. Power down. Let tubes COOL OFF. Switch right and left channel tubes. Power up. See if whine switches to other speaker. Report back.
     
  3. Paul K

    Paul K Senior Member Thread Starter

    Location:
    Toronto, Canada
    Steve, they aren't going through the speakers at all. You put your ear near the tubes and a high whine is what you hear - kinda like the whine present on the old "Forever Changes" cd only higher!
     
  4. Steve Hoffman

    Steve Hoffman Your host Your Host

    Lightly tap each tube. Does the whine stop? What kind of EL-34's?
     
  5. Paul K

    Paul K Senior Member Thread Starter

    Location:
    Toronto, Canada
    Svetlanas and they are about a month old. Anyway, I did this before and nothing really changed and I could'nt localize which one it was anyway. I turned everything back on and am torturing (naw) my girlfriend with Sprit's first record, and the whine isn't there currently. 20 min and counting.

    Any suggestions as to what is happening?
     
  6. Paul K

    Paul K Senior Member Thread Starter

    Location:
    Toronto, Canada
    Anyhoo, I am incommunicado for the next hour. Jeeves and Wooster is calling so DVD's are on the communal horizon. Thank you for responding and if you have any thoughts on this further (and anyone else too!) then please let me know what is thought. I will be looking at this again.
     
  7. Sckott

    Sckott Hand Tighten Only.

    Location:
    South Plymouth, Ma
    You might want to rotate tubes until you find the one that whines. This does happen, especially to Russian tubes. When I buy for a quad, I buy 5.

    1 extra for luck. They may test great, but I've had one whine on me. They don't whine on a tester because the tester cannot emulate "load".
     
  8. Paul K

    Paul K Senior Member Thread Starter

    Location:
    Toronto, Canada
    Whining tubes is common? Does this affect the life of the tube?
     
  9. Sckott

    Sckott Hand Tighten Only.

    Location:
    South Plymouth, Ma
    Bad apple. Dispose. Do not pass go. Do not collect $200. Common? No.

    But when it happens, not much you can do. Some can try resoldering the pins, but me no find that to work. :shake:

    Find the baddie and pluck.
     
  10. Steve Hoffman

    Steve Hoffman Your host Your Host

    Invest in NOS tubes...
     
  11. Paul K

    Paul K Senior Member Thread Starter

    Location:
    Toronto, Canada
    Ok, that would be the way to go. (not right away, but soon I guess!)
    Thanx everybody for the help. Now to ponder how much this is all gonna cost me...
     
  12. Gary

    Gary Nauga Gort! Staff

    Location:
    Toronto
    Start hunting. :)

    There are places - I can help if you want.

    G
     
  13. Paul K

    Paul K Senior Member Thread Starter

    Location:
    Toronto, Canada
    Yep, PM me buddy and I hope you are Beatled out!
     
  14. mcow1

    mcow1 Sommelier Gort

    Location:
    Orange County, CA
    How loud is it? Can you hear it from where you listen or just when standing next to the amp. Are you sure it's not just transformer hum?
     
  15. Paul K

    Paul K Senior Member Thread Starter

    Location:
    Toronto, Canada
    Transformer hum is 60Hz right? This is more like 16KHz
     
  16. PMC7027

    PMC7027 Forum Hall Of Fame

    Your ears are good!
     
  17. Tony Plachy

    Tony Plachy Senior Member

    Location:
    Pleasantville, NY
    Syd, One of the transformers on my conrad-johnson P12 monoblocks makes a high pitch whine (its lower than 16KHz because I cannot hear 16KHz any more) when the weather gets cold and I first turn it on. Sometimes it takes as much as a 1/2 hour to go away. Be sure it is the tubes, transformers can whine too.
     
  18. Sckott

    Sckott Hand Tighten Only.

    Location:
    South Plymouth, Ma
    ....and transformers can whine because of bad tubes or power supply problems too. Same high whine.

    Sometimes you just have to pluck tubes out of it, turn it off, listen, repeat before you find the whine.
     
  19. NOSValves

    NOSValves New Member

    Location:
    Burton, Michigan
    Often the problem with the modern tubes coming out of Russia and China are the tube pins have high and low spots and are generally made of less conductive metal then NOS. I bet you have a tube that just refuses to get a proper contact in the tube socket. This is especially true with vintage amps where the sockets can have serious oxidization. Work the tubes in the sockets while the amp is on and the volume low and see if the noise changes with real movement rather then tapping. If it persist and is constant then it is a bad tube.

    Craig
     
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