Can AC power quality affect amplifier sound?

Discussion in 'Glowing Bottle Tube Amp Forum' started by Mike Simpson, May 6, 2021.

  1. Mike Simpson

    Mike Simpson Doctor of Teleocity

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    Can the power be somehow dirty and affect the clean sound of the amp?

    In playing a lot of gigs and plugging everything in a lot of different places once in a while my guitar amp (or someone else's or both) does not sound as good as usual. I suppose it could be somewhat affected by the room but I don't think that's it. Last week the amp sounded a little dirty and was not clean at the same settings as I always use. I keep a volt meter / circuit tester on the main power strip so I know the voltage was a constant @117 at the gig and it was grounded correctly. I might get a dirty sound with the volume set at 3 when it should be much cleaner.

    I'm usually playing a 74 Princeton with a 12" Cannabis Rex, other amps on stage are a Brown Deluxe and a tweed Bassman or Pro. All the amps are kept serviced in good condition.

    Not a "brown sound" or high or low voltage question but can there be a harmonic distortion influenced by line power? I know it sounds like electrical voodoo...
     
  2. kennl

    kennl Tele-Afflicted

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    monitoring the voltage was a good idea
    since the voltage was constant, I would suspect the room
    I've played a local venue where the window glass to my left reflects the floor wedge monitor sound directly at my head, and standing waves sound distorted a certain frequencies
    a step forward or back makes a huge difference
    rooms can be an audio nightmare
     
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  3. Zepfan

    Zepfan Doctor of Teleocity Gold Supporter

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    Yes.
    Home wiring, computerized controls for the home and security devices, light dimmer switches, ceiling fans, kitchen appliances, fluorescent bulbs and ballast light fixtures can effect your amp and guitar through RF and electrical. Bad fuses or breakers in the box can be a problem and I'm wondering about the new computerized meters.
     
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  4. Killing Floor

    Killing Floor Friend of Leo's

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    Absolutely.
     
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  5. Boreas

    Boreas Friend of Leo's Silver Supporter

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    Did you use the same length cable?

    I would investigate other sources of noise IF switching to an outlet on a different circuit yields the same dirt.
     
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  6. Mike Simpson

    Mike Simpson Doctor of Teleocity

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    Maybe they had something electrical running that isn't usually running, we have played there many times.
     
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  7. Mike Simpson

    Mike Simpson Doctor of Teleocity

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    Everything was the same in my setup as other times. I didn't try different outlets, I used the same one as I always do at that venue.
     
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  8. Dostradamas

    Dostradamas Tele-Meister

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    I watched a rig rundown of Angus Youngs many Marshals on stage.

    The most expensive, highest tech units they had backstage were the AC power conditioners/ regulators for the amps.

    They have it dialed to pristine, exact voltage and hertz going into those vintage Marshalls.

    Yes input AC on tube amps can make a significant difference.
     
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  9. ThermionicScott

    ThermionicScott Poster Extraordinaire

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    I think Neil Young uses that stuff, too. If it's not a clean 117V/60Hz sine wave, he can (supposedly) hear it. ;)
     
  10. NoTeleBob

    NoTeleBob Tele-Afflicted

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    Test question: How does it sound now back at home? Is it the old sound or the dirty new sound?
     
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  11. MuddyWolf

    MuddyWolf Tele-Meister

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    Higher quality is always better. That's why I prefer to use high grade electricity in stead of the kind from a tap. Power from melted snow is real good. My amps drink it up.
     
  12. Mark617

    Mark617 Tele-Meister

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    Yes there are harmonics throughout. It’s just to what degree and where you’re plugged in
     
  13. Chiogtr4x

    Chiogtr4x Doctor of Teleocity

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    We once had a 'brown out' moment at a fundraiser gig at a hotel restaurant in DC ( Years ago)

    Our band was doing our usual blues R&R stuff, fun!

    Then during our second set, my guitar amp ( Blues Jr.) gets super distorted and super quiet ( I'm thinking my amp's tubes are dying!),

    But then noticed same volume drop with the PA vocals and ceiling lights are dim. So we stop, freak out for a minute.

    Apparently there were kitchen appliances or equipment turned on during the gig, competing for juice on the same circuit.

    Someone on hotel maintenance took care of issue, took care of the problem- back to swingin', yay!
     
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  14. TwoBear

    TwoBear Tele-Holic

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    Older days before the overdrive and distortion pedals in bars you could find neon lights on the same AC as the band. Fast forward to the heavier overdrive tones and the popular dance clubs and they started to learn real quick that some of those rooms were unusable and they had to have the electricity completely rewired. So what about this club or these clubs any details or can you reach over and shut off any neon lights of course don’t be touching your instrument or mic or anything.
     
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  15. magicfingers99

    magicfingers99 Friend of Leo's

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    Pink Floyd once had a gig crapout when the lighting controls (dimmers at that time) were on the same circuit as the amps/PA.
    so yes...
    amps want a nice sine wave at whatever their rated current is amps/volts. The concept of running your amp thru a variac is similar to a sagging line voltage but in a controlled manner. So very definitely you can see this is being used to change the "qualities" of the sound amp output.
    power is complicated in a performing environment

    here's fun with lights


     
  16. bendercaster

    bendercaster Tele-Afflicted

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    Yep. My Vox gets dirty when the dishwasher runs.
     
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  17. Ringo

    Ringo Poster Extraordinaire

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    The current can certainly fluctuate out of the receptacle, it's not always or often 110 or 115 v, I use a Tripplite Line Conditioner, it regulates the voltage, plus it has some filtering etc...
    There are other much more expensive units that do that also. It can make a bit difference in the sound of your amp, whether it's tube or SS, digital gear seems even more sensitive to low voltage IME.
     
  18. Nickfl

    Nickfl Friend of Leo's

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    Just for perspective you asked a technical question in the general tube amp discussion area, so you're going to get a lot of conventional wisdom and armchair commentary from people who couldn't tell you what the difference between a capacitor and a resistor is. So just keep that in mind and keep your salt handy because you're going to need many grains...
     
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