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Stupid Question Regarding Power Cords

Discussion in 'Amps and Cabs [BG]' started by agreatheight, Jan 11, 2013.

  1. So I just completed a long cross country move from Arizona to New York to Maine, and I recently unpacked all of my non-essential musical items. Included were several amps (bass, guitar, power). Long story short, the power cords to each of those amps were all mixed together and not labeled, so I have no idea which cord goes to which amp. To further complicate matters, only two out of eight are marked with 'specs' (both as 10 amp / 125 volts). So are all power cords created equal? If so, thanks all! If not, how the hell can I match them up?

  2. two fingers

    two fingers Opinionated blowhard. But not mad about it. Gold Supporting Member

    Feb 7, 2005
    Eastern NC USA
    They should all be fine in any amp that they fit in. Some are better quality than others. But functionally, unless they crap out, they are the same. Mine all live in the gear box that travels around with me and I just grab whichever one is on top.

    PS: Not a stupid question. Not everyone is an electrician or electronics guy. I'm sure you are great at something I would have to ask basic questions about.
  3. skychief


    Apr 27, 2011
    South Bay
    For bass amp applications, yes.

    They all carry 120vac @ 10 amps or less which will suit any bass amp.
  4. What about for guitar heads or power amps?

    The guitar head I have is a custom tube job:
    10 watts, switchable 16 / 8 / 4 ohm.

    The power amp I have is a QSC GX5:
    8 ohm; / both channels driven / 1 kHz: 500 W
    8 ohm; / single channel driven / 1 kHz; 600 W
    4 ohm; / both channels driven / 1 kHz; 700 W
    4 ohm; / single channel driven / 1 kHz; 850 W

  5. Lol, true on that. Every have questions on Photoshop, hit me up!
  6. skychief


    Apr 27, 2011
    South Bay
    Still applies.

    Just dont try to run your electric lawnmower or weedwhacker with these power cords.

    They will heat up and burst into flames. :eek:
  7. Thanks two fingers and skychief - I appreciate the help!
  8. two fingers

    two fingers Opinionated blowhard. But not mad about it. Gold Supporting Member

    Feb 7, 2005
    Eastern NC USA
    Roger that.

    And for your power amps you are still good to go. The electrical world is trying to protect us from ourselves. Have you ever noticed an outlet (maybe in a commercial building) that has two of the slots turned sideways? (see pic) That's (probably) a 15A 240V outlet. The reason the slots are turned sideways is to keep you from plugging in a device that is not rated for that much juice. In many cases, the same concept applies for power cords. If it fits, it's fine. If the device is rated for a bunch more juice, it will (likely) be shaped differently.

    Attached Files:

  9. That all makes sense to me! Thanks again!
  10. T_Bone_TL


    Jan 10, 2013
    SW VT
    They should all be (but it can be VERY SUBTLE if you don't know what you are looking for) marked with the size & type of the wire, as well as a UL symbol. "number of amps" is not uniformly marked, but wire gauge is.

    99% of the interchangeable "IEC" (also same connector most computers use) powercords are going to be marked something like:

    (UL) SJT 18/3 (and a bunch of other gobbledygook.)

    It's usually imprinted (no color, just an indent) or faintly printed repeatedly (often 2 foot repeat) along the length of the cable.

    If you happen to have some that are actually "better" (many that are "thicker" than average just have fat rubber) they might be marked 16/3 or even 14/3 (the lower the first number, the fatter the wire) and those should go to whatever draws the most power - evidently your GX5 amp.

    The specs you need to look at for the GX5 are the power INPUT, which are a bit further down the chart. You're looking at the input power input cord, after all. That one probably should have a 14/3 power cord, or at least a 16/3. I've picked out just the amps in and the GX5 from the spec chart for the whole series I found:

    QSC GX Specs

    AC Current, 120 VAC GX5
    Operating Condition AC amps
    Idle 0.3
    8 + 8 ohms, 1/8 power 1 3.3
    8 + 8 ohms, 1/3 power 2 8.5
    8 + 8 ohms, full power 3 16.2
    4 + 4 ohms, 1/8 power 1 5.8
    4 + 4 ohms, 1/3 power 2 11.2
    4 + 4 ohms, full power 3 24.5

    1 1/8 power represents typical operating conditions
    2 1/3 power represents peak program levels
    3 Full power is breaker limited to short periods

    To what extent are "typical" "peak" and "full" power actually being drawn? We can guess a bit: Note 3 mentions that peak power is limited to short periods by a circuit breaker, which are probably "very" short periods, since normal 120V outlets are limited to 15 amps (plugs with just one of the blades turned sideways can run 20 amps - the matching outlet in the wall has a "T" shaped hole on one blade, so both 15 and 20 amp plugs can be used in it, usually.) So 24 amps for more than the briefest time is not really OK for 120V input (can be fine with 240V input, where it would only be 12 amps, as explained by another note I didn't copy.) So unless you trip breakers a lot, "full" either happens for milliseconds or not at all.

    Still, worth a careful look to see if one cord really IS different from the rest, and belongs in that beefy power amp.
  11. ::::BASSIST::::

    ::::BASSIST:::: Progress Not Perfection.

    Sep 2, 2004
    Vancouver, BC Canada
    Related question...

    My QSC PLX2402 has an attached power cord which is quite thick. The amp is rated for up to 2400w but I would not use more than 1500w. However, the extension cord I use is average diameter. Seeing that super heavy duty power cord coming from the amp makes me wonder if I should be using an equally robust extension cord.

  12. B-string

    B-string Supporting Member

    Yes if you push the amp much at all.
  13. JTE

    JTE Supporting Member

    Mar 12, 2008
    Central Illinois, USA
    Again, inspect the amp's power cable closely to find its AWG wire size. Use an extension cord.that's at least the sane size, bearing in mind that the smaller the number, the larger the wire. 14ga is BIGGER than 16ga.

  14. Bassamatic

    Bassamatic keepin' the beat since the 60's

    YES - It is important to check the actual gauge - some cords are fatter just because they have more insulation. AND your extension cord can and maybe should be larger than your line cord, as it has a much longer distance to run.
  15. Andyman001

    Andyman001 moderation must be taken with a grain of salt

    Feb 11, 2010
    S/E Idaho
    Also for a very long cord it's better to be bigger than the power cord to allow for "voltage drop" if you are using a high power amp.

    Edit: long = 100' or more
  16. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

    Mar 5, 2021

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