Help...amp losing volume but not gain

Discussion in 'Amp Central Station' started by schenkadere, Jun 16, 2021.

  1. schenkadere

    schenkadere Friend of Leo's

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    I have a little Randall Diavlo 5W combo that I love. It never leaves my bedroom and never gets played super loud. Last night, while playing, my volume would fade out and then come back, but my gain/distortion level would pretty much remain. Any ideas? I'm assuming a tube? They're JJs and don't have a ton of playing time on them.
     
  2. northernguitar

    northernguitar Friend of Leo's

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    Output tube? Tubes can die, right outta the box.
     
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  3. ISmellSmoke

    ISmellSmoke TDPRI Member

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    I suspect the antics of an evil clown.

    Or perhaps the speaker connection has somehow become less than optimal.
     
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  4. schenkadere

    schenkadere Friend of Leo's

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    The power tube I assume.
     
  5. schenkadere

    schenkadere Friend of Leo's

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    maybe the clown, but the amp never even moves...I can't imagine a speaker connection failing.
     
  6. Greg70

    Greg70 Tele-Meister

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    Sometimes a dirty tube socket can cause things like that. I would try removing and reinstalling the tubes a few times and see if it changes. Be sure it is off and unplugged when you do that so you don't get any loud pops.
     
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  7. northernguitar

    northernguitar Friend of Leo's

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    Yep. That’s where I’d start.
     
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  8. Les Paul lover

    Les Paul lover Tele-Holic

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    I suppose the power valve is on its way out. Assuming you get your gain from the preamp only, that would explain why your gain stays the same (preamp gain, from ECC83) and why your volume is fluctuating (power amp provides volume amplification before adding their own overdrive when pushed hard).

    Whilst I don't really think that's it re: the speaker connection (the volume wouldn't fade in and out, it would be on/off), it's worth keeping in mind that connections don't need to move to possibly fail. A poor solder joint might be affected by the raising temperature within the amp chassis as it's being played, or component might suffer heat related failure.

    Lots of things can happen, but here, replace the power valve 1st.
     
  9. schenkadere

    schenkadere Friend of Leo's

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    I actually have an extra tube to test and verify this. Thanks guys!
     
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  10. dan40

    dan40 Friend of Leo's

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    Not sure if this amp has an effects loop or not but they can cause issues similar to yours. If plugging a cable directly into the send and return jack (no pedals connected, just the cable) fixes your problem, it's a good bet the switch contacts in the jacks need a good cleaning.
     
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  11. Daytona.57

    Daytona.57 Tele-Meister

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    I was experiencing, the same issue with all my amps and my partner's large frame quilting machine.

    The volume of the amps and quilting motors, would speed up and slow down.

    A contractor metered the home electrical voltage, and measured fluctuations, from 80-138V, at the outlets.

    I tried surg protection and it did not work, so, we aquired a Furman AP-1800 voltage regulator and we haven't had a problem since.


    It is a relatively, inexpensive solution, considering the replacement costs for my amps, guitar pedals and quilting machines. The Furman AP-1800, has banks of outlets, for analog and digital gear. It regulates the voltage to 120V, +/- 3V.

    We unplug the Furman and all all other expensive equipment, including my pedalboard, when not in use.


    Edit: correct auto correction on upload.
     
    Last edited: Jun 18, 2021
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  12. schenkadere

    schenkadere Friend of Leo's

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    It does have an effects loop and I'll look into that too...thanks...waiting for the weekend.
     
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