Traynor YSR-1 Popping-Preamp Tubes?

Discussion in 'Amps and Cabs' started by shanetram, Oct 20, 2008.

  1. shanetram

    shanetram Supporting Member

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    Hi I recently bought a used Traynor YSR-1 Custom reverb. When it arrived one of the power tubes had broken so I replaced all of the tube with some sovteks I had lying around. The amp sounded pretty darn good so I bought some Tung-EL34s and JJ ECC883s. The first time I used the amp after the swap it sounded phenomenal. The next two times it would work for a while and then when I took it in and out of standby or muted it and unmuted it with my tuner I'd get loud popping and squealing. The caps look good and it appears as if the whole amp has been recapped not too long ago with spragues and mallorys. I was just reading about quality issues with the JJ preamp tubes. Is this most likely the culprit?

    Thanks, Shane
     
  2. shanetram

    shanetram Supporting Member

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    Bump, no suggestions?

    Thanks
     
  3. fullerplast

    fullerplast Senior Member

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    Unless you threw out your other tubes, you have everything you need to answer your own question.

    Specifically, swap out the preamp tubes one at a time. If no change, swap out the power tubes as a set.

    Remember to check the bias on the power tubes. I have a feeling you may not have done this, as that amp does not have a bias pot stock....you need to change the voltage divider or add a pot. That bias voltage goes to the tremolo circuit first, then the power tubes.
     
  4. shanetram

    shanetram Supporting Member

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    B/c the bias is not adjustable you're right I didn't test it. How do I find out what tube rating should be in there so I can buy tubes that match the amp better if I find out it's the power amp tubes?
     
  5. fullerplast

    fullerplast Senior Member

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    Well, the only power tubes that are commonly rated that way (AFAIK) are EL84's for cathode biased amps.

    I have no idea of your experience with amps, but the easiest and safest way to check bias is with a bias meter. There are several types-Weber sells one. Once you have that you can either:
    1) buy tubes and sort them yourself (using the ones that are within range at the existing bias voltage),
    2) have your amp modified to have correct bias for a particular set of power tubes, or
    3) have your amp modifed for an adjustable bias pot (best approach IMHO).
     

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