DRRI issue, please help

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by IbanezAFS75, Apr 21, 2008.

  1. IbanezAFS75

    IbanezAFS75 Member

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    Well i went to a friends house tonight with my DRRI, everything went great. I get home and power it on, go to turn the standby off it gives a semi loud pop, the amp works completely fine, and nothing looks out of the ordinary, but it does this everytime.

    main reason i'm worrying is that i'm trading the amp this week and i'm hoping its not much of a problem.
     
  2. Tbone135

    Tbone135 Member

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    No problem, it's pretty typical as I recall. Something about "arc-jumping".
     
  3. KCWM

    KCWM Member

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    after reading a couple of articles on here, I don't turn off my standby switch.
     
  4. IbanezAFS75

    IbanezAFS75 Member

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    what do you mean?

    wait, maybe i didnt clarify myself, turning standby to off so you get power to the amp, as the switch it normally on standby, no?

    Glad to hear its not a big deal, i talked to someone who said it might be a microphonic tube, we'll just have to see.
     
  5. IbanezAFS75

    IbanezAFS75 Member

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    played the amp again today, was playing a bit and then the volume dropped.

    thats more or less a preamp tube issue, right?
     
  6. KCWM

    KCWM Member

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    I leave my standby switch in the on position the entire time, that way, I just turn the power on and I'm good to go. I very rarely flip the standby switch. Then again, I never play live, so I'm not in a situation where I want to have access to the tubes.

    I forget which thread it was, but there was a pretty good back and forth discussion.
     
  7. Bonenut

    Bonenut Member

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    This is the correct way to turn a tube amp on and off. Do this every time.

    Turning amp on procedure:
    Put standby switch to standby, turn power switch on. Let warm up for 2 minutes, flip standby switch to on.

    Turning off procedure:
    Leave standby switch to on, turn off power switch.
     
  8. mbratch

    mbratch Member

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    I'll quote Old Tele Man from a previous thread:
    "Cathode-stripping" of the power tubes can occur when the PLATE voltage comes up BEFORE the BIAS voltage does...

    ...this condition occurs more often than many people realize...

    ...because of the "heavier" filtering (ie: large resistor-capacitance (RC) values) often used in the BIAS circuitry.

    Hence, think of a STANDBY switch as a mechanical "insurance" policy for the "life" of your expensive output tubes.

    So if you don't use your standby switch as Bonenut suggests, you can shorten the life of your power tubes because of "cathode stripping".
     
  9. phsyconoodler

    phsyconoodler Member

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    Cathode stripping does not occur in tube amps with such low voltages.It is a problem usually associated with voltages above 700vdc.
    Take the princeton reverb for example.No standby switch in sight.And what about tweed amps?Most had none.
     
  10. alltone

    alltone Member

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    Would the fact that these amps had a tube rectifier have anything to do with that?:horse
     
  11. alltone

    alltone Member

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    :agree
     
  12. alltone

    alltone Member

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    :agree
     
  13. mbratch

    mbratch Member

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    Thanks phsyc, didn't realize that. I thought the bigger Fender amps had the standby because they would have the problem, but evidently Fender put the standby on the bigger amps perhaps to save a little power? Or they took longer to warm up? Or maybe they just felt like it (which I know is possible with Fender). :)
     
  14. Bonenut

    Bonenut Member

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    Or maybe because they don't use indirectly heated tube rectifiers? If you turn on a tube amp with a silicon rectifier (or a directly heated rectifier tube) you're slamming your power tubes with full voltage before the cathode can emit electrons, since they haven't warmed up to a sufficient temperature to do so.
     
  15. IbanezAFS75

    IbanezAFS75 Member

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    I dont believe it has anything to do with the standby, i turn it on properly every time i use the amp.
     

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