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Correct power cord for Amp head?

Discussion in 'Amps and Cabs [BG]' started by PockySteve, Jun 11, 2019 at 11:51 AM.


  1. PockySteve

    PockySteve Supporting Member

    Nov 15, 2018
    Pennsylvania USA
    Hi All,
    I just purchased a used Hartke LH500 500w amp head, but it didn't come with a power cord. I tested it with a borrowed cord but I need to buy one now. I've searched TB and on Google but still not sure what specs a safe and sufficient aftermarket replacement power cord would be. Below is a pic of the back of the amp. Thanks for your help!
    View attachment 3442875
     
  2. ArtechnikA

    ArtechnikA I endorsed a check once... Gold Supporting Member

    Feb 24, 2013
    SEPA
    Any standard IEC 20 cable will work just fine.
     
    JC Nelson, Aqualung60, Inara and 5 others like this.
  3. Wisebass

    Wisebass

    Jan 12, 2017
    Lost in Space
    Hi PockySteve :)

    Buy one that is loooooong!

    That said, even the longest cable will always be two inches too short. :D


    may the bass be with you

    Wise(b)ass
     
  4. basscooker

    basscooker Commercial User

    Apr 11, 2010
    cincy ky
    Owner, ChopShopAmps
    Whats the best power cord for metal?
     
  5. basscooker

    basscooker Commercial User

    Apr 11, 2010
    cincy ky
    Owner, ChopShopAmps
    Discord
     
    dannylectro, davesultra, JRA and 4 others like this.
  6. zon5string

    zon5string Supporting Member

    Aug 20, 2007
    San Diego, CA
    A5.
     
  7. zon5string

    zon5string Supporting Member

    Aug 20, 2007
    San Diego, CA
    Have one of your IT-employed friends bring you a server power cable.
     
  8. pfschim

    pfschim Just a Skeleton with a Jazz bass Supporting Member

    Apr 26, 2006
    SF Bay Area
    +1 to getting a long one (at least 15ft), and you probably don't need anything heavier than a 16 or 18 gauge cable.
     
    ExaltBass and PockySteve like this.
  9. Oh stop it!! :D
     
    JRA, Son of Wobble, Wisebass and 2 others like this.
  10. Wasnex

    Wasnex

    Dec 25, 2011

    The amp is fused at 10A. I believe an 18AWG IEC chord meets the minimum current requirements, but I would upgrade to at least a 16AWG which is rated for 13A, or 14AWG which is rated for 15A. I believe the IEC connector type you need C13 and the standard grounded US plug is Nema 5-15P.

    So Google "IEC cord 16AWG C13" or "IEC cord 14AWG C13" and you will get plenty of hits. You local office supply store probably stocks what you need.
     
    dkelley, JRA, elgranluis and 2 others like this.
  11. DWBass

    DWBass The Funkfather

    Snatch one from an old desktop computer.
     
  12. FWIW my Mesa D800+ shipped with an 18ga cord.
     
    sludgetail and PockySteve like this.
  13. PockySteve

    PockySteve Supporting Member

    Nov 15, 2018
    Pennsylvania USA
    Awesome info - Thanks Wasnex!
     
    Wasnex likes this.
  14. I agree with those saying splurge and get one thicker and longer. No Michael Scott jokes, please.
     
    Charlzm likes this.
  15. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    For audio applications, even though the fuse may be specified at 10 amps, that dictates the minimum ampacity that the cordset must carry for fault clearing purposes only. This equates to an 18 gauge cordset.

    For performance purposes, you need to look at safety agency required "rated AC input current or rated AC input power"... but this is not present on either the back of the amp in any picture I saw, nor is it in the manual either.

    So, going old school and calculating it, 500 watts into 4 ohms at worst case 25% duty cycle (twice the safety agency's minimum required amount) is 500 x .25 = 125W. Since this is a linear amp with a line frequency power supply, we can consider the overall efficiency at around 40% (it's probably a wee bit higher) so take the 1/4-duty cycle audio power divided by the efficiency and you get rated AC input power. 125/.4 = 315 watts. Now for current (in 120V markets), 315W/120V= 2.6 amps. So, in practice, an 18 gauge power cable is pretty "wild overkill".

    Even using rated audio power with 100% duty cycle (sine wave testing), the maximum AC power draw will be 500W/.4 = 1250 watts or right about 10 amps (though the amp would likely shut down after a few minutes to (rightly) protect itself. Of course your speakers wouldn't last near that long under these conditions.

    In practice, every player we have ever had test for duty cycle under the most extreme conditions that resulted in acceptable (or usable) bass signal pretty much maxed out at 50% duty cycle so 100% duty cycle isn't a practical metric anyway.
     
  16. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    There's no practical performance benefits by going with anything larger than 18 gauge for this application. None.

    Going with 12 or 14 gauge may cause problems with the IEC connector remaining firm in the socket, the added weight and stiffness of the cable can cause issues in some applications.
     
  17. nilorius

    nilorius

    Oct 27, 2016
    Riga - Latvia
    It's a simple standart.
     
  18. birminghambass

    birminghambass Supporting Member

    Sep 18, 2002
    Birmingham, AL
    You need one of those $200 power cables Victor Wooten endorses....
     
  19. Gravedigger Dav

    Gravedigger Dav Supporting Member

    Mar 13, 2014
    Fort Worth, Texas
    [​IMG]
     
  20. Wasnex

    Wasnex

    Dec 25, 2011
    Yep a Trace Elliot ELF with a 14AWG will probably result in something like the tail wagging the dog.

    All of my bass amps are big and heavy, and I have not had any problems with 14AWG. Totally overkill though. Given the short length of cable involved, I prefer 16AWG. This size and stiffness is just right for my taste.

    Is there a certain power level where 18AWG is too small?
     

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