Do capacitors have anything to do with headroom/punchiness?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Creighton, Feb 7, 2012.

  1. Creighton

    Creighton Member

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    Do caps have anything to do with the volume/headroom of a tube amp?

    If an amp loses a slight bit of headroom/power what would be the first thing to look at? Obviously tubes, but if those all test strong, what else could be implicated?

    I'm seriously considering taking an amp building class to learn basic assembly/troubleshooting skills. It would be awesome to know how to do this stuff myself rather than having to rely on amp techs. And asking questions online :)
     
  2. HughesP

    HughesP Member

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    Yes, the power supply has a lot to do with headroom & punchiness of the amp.

    How old is your amp? Electrolytic caps eventually start to dry out and you loose the punchiness & headroom (and some volume) that the amp originally had.
     
  3. GearHeadFred

    GearHeadFred Member

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    Yes filter caps would be next... They should normally be good for 10-15 years before you need to replace them due to "natural causes".
     
  4. Creighton

    Creighton Member

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    Amp was made in the mid 90's. It's a sovtek mig 50 head. Sounds unreal.

    So filter caps then. Replacing the filter caps isn't going to alter the tone at all is it? Because it sounds really good, tone wise. I just perceive a slight loss of headroom.
     
  5. Blue Strat

    Blue Strat Member

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    EVERYTHING affects tone.

    How old are the power tubes? I suspect those before the power supply caps though it's getting close on those.
     
  6. wyatt

    wyatt Member

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    I kind of doubt it's the caps. While it is recommended to pros to get their electrolytic caps replaced every 15-20 years, that is preventive maintenance scheduled before any issues should arise. That said, I really don't know anything about the Russian caps used in the amp.

    But the first things to look at are the tubes. They'll wear out long before the caps. And if you've replaced them, the new tubes might not be biased correctly, or might just not be as good of tubes.

    And yes, replacing wore caps does alter the tone and feel of the amp, besides more headroom and a tighter, punchier feel, you'll notice a fuller sound with more/tighter low-end.
     
  7. Creighton

    Creighton Member

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    They're the original tubes I believe, both preamp and power.

    But, they all test strong on the Heathkit TC-2. That and I had it in at Schroeder audio in Chicago over the summer and he went through the whole thing and came back with nothing but a recommended cap job, as a preventative measure. He found nothing wrong with the amp or tubes.

    The way he said it was that the caps looked fine but that was next on the list, which agrees with what some of you have said.
     
  8. phsyconoodler

    phsyconoodler Member

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    Tubes.Listen to Blue Strat.Tube testers do not run the tube at the voltage it sees inside an amp so the results are not real-world accurate.A mid-90's amp with the original tubes is long overdue for new ones.
     
  9. Zingeroo

    Zingeroo Member

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    The tubes might test good, but they definitely can still be wearing down. Just like how a set of tires with 60k miles still has some tread on them, technically they're still good, but they won't stop your truck as quickly.
     
  10. Blue Strat

    Blue Strat Member

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    Since you'll need them sooner, than later, anyway, I recommend trying new tubes before you do anything else. Buy them at Guitar Center.
     
  11. wyatt

    wyatt Member

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    Well, hell then,...

    To use a different auto analogy than Zingeroo, you're talking about replacing the transmission oil but ignoring you're long overdue for changing the motor oil.

    If you gig out, it's a good idea to replace those caps in the next 5 years, just to be on the safe side...but you probably should have replaced those tubes 5+ years ago. When tubes were out, they typically do it so gradually that you don't notice the change until their performance so bad it can't help but be noticed.
     
    Last edited: Feb 8, 2012
  12. Creighton

    Creighton Member

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    Update: I replaced all the tubes, didn't notice much difference at all. Still lacking warmth, headroom, volume and punch that the amp had previously. So, on to a cap job I guess. I've got a tech who's going to go through it and see what's up.
     
  13. Tommy_G

    Tommy_G Member

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    Did you replace the speaker recently. Maybe it just got broken in....they sound crisper when they're new and softer when they're old.

    Maybe you played too loud for too long, and you wrecked a certain range of hearing. I don't think many guitarists make it to retirement with a full set of ears.
     

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