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Power amp only has XLR speaker outs - what to do?

Discussion in 'Amps and Cabs [BG]' started by Planet Boulder, Mar 23, 2003.


  1. Planet Boulder

    Planet Boulder Hey, this is a private residence...man Supporting Member

    Nov 10, 2001
    6,482 feet above sea level
    I once had impure thoughts. Oh, and I pluck my ear hair.
    I have an older Trace Elliot RA500X power amp that only has XLR speaker outputs, but my cabs only have 1/4" inputs. I am looking for a female XLR to female 1/4" adapter, but so far, I have only found such for mics, which obviously wouldn't work for my situation, due to impedence issues with the adapter.

    Does anyone else have experience with this and, if so, can you point me in the right direction?
     
  2. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    Take a 1/4 to 1/4 speakers cable and replace one end with the proper XLR plug. If you're not up to it have a local tech do it for you. Shouldn't cost too much.
     
  3. Planet Boulder

    Planet Boulder Hey, this is a private residence...man Supporting Member

    Nov 10, 2001
    6,482 feet above sea level
    I once had impure thoughts. Oh, and I pluck my ear hair.
    So I moseyed on over to my local music store today and, upon their advice, purchased a couple of balanced, line-level cables with XLR and 1/4".

    The techie there stated that, as long as the cable isn't too long, I should be fine - it's what he does with his setup.

    Does anyone see this as being an issue?
     
  4. do not use line level cables as speaker cables!!
     
  5. Planet Boulder

    Planet Boulder Hey, this is a private residence...man Supporting Member

    Nov 10, 2001
    6,482 feet above sea level
    I once had impure thoughts. Oh, and I pluck my ear hair.
    Please elaborate. I figured it would be a bad idea, but the jokers at my local music store seemed to think it would be alright.
     
  6. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    The wire inside a line level cable is too small for speaker wire. It's probably 20 gauge or smaller (larger number). Plus, the ground side is a foil or wire braid around the outside of the + and - conductors...again, not intended for carrying the level of current that a bass amp is going to put out.

    If a Technician is willing to do that with his own gear, I'd go to another shop. It wouldn't take too long for someone with a soldering iron and some wire cutters to modify a real speaker cable.

    On the flip side of that, I'd also look into having the XLRs swapped out with panel mounted Speakons if it could be done easily.
     
  7. Planet Boulder

    Planet Boulder Hey, this is a private residence...man Supporting Member

    Nov 10, 2001
    6,482 feet above sea level
    I once had impure thoughts. Oh, and I pluck my ear hair.
    Good call, Billy. I was skeptical as well (having heard the dangers in the past of attempting to use instrument cable for speaker cables) and, in fact, I asked everybody who worked there about it. Nobody seemed terribly sure of it, but didn't think it would hurt.

    I'll just return them and have a couple of cables made.

    Many thanks, guys - great advice!!!
     
  8. Phat Ham

    Phat Ham

    Feb 13, 2000
    DC
    Does anyone know which pins you'd connect the + and - of the speaker wire to? And is the third pin unused?
     
  9. Pete Brunelli, aka "Fretlessrock" makes the finest custom instrument and speaker cables I have ever seen, and his prices are too low.

    You can email him at pete@petebrunelli.com and I'm sure he will make you what you want.

    Here's a photo of a bass cable he made up for me:

    [​IMG]

    I'm awaiting some of his speaker cables.

    There's a cool thread about him in the "gear for sale" forum of the Dudepit.

    Aloha,

    Jonathan
     
  10. That's a burly lookin' cable! Looks like an extension cord for power tools.
     
  11. Well, I guess there is a 1st time for everything. I've never seen 3 connector XLR's used for 2 connector speaker outputs so I think we're all shooting in the dark on this one. Unless you open up the amp and look inside, there is no of knowing which terminal Trace used as + and - or even what the 3rd terminal is supposed to be used for. I did a search for "Trace Elliot Power Amp" and came up with nothing so you're gonna have to use trial and error on this one.
     
  12. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    Perhaps a thread titled Trace Elliot XLR pinout? would get a quick response.
     
  13. icks

    icks

    Jul 12, 2001
    Charleroi, Belgium
    Am I the only one to do my own cable ?

    Just buy a jack 1/4 and a XLR, 1 meter long cable, use a small welder system and here ya go ...
     
  14. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    Welder? I think you meant solder :)

    I've got some XLR to Jack speaker cable in front of me now and I've just opened up the XLR end. It looks like pin 3 is positive. The negative wire is connected to pin 1. There is also a small piece of wire joining pins 1 and 2.

    The pins are configured like this:-

    .O2......O1
    ......O3

    Hope that helps.
     
  15. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    Pete,

    Are the pins numbered on the inside? If not and someone is looking at it from the wrong perspective, the amp's output would get shorted...:(
     
  16. I'm pretty sure it's like this:

    [​IMG]
     
  17. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    Holy Sheet......Ignor my post Ignor my post!
     
  18. Planet Boulder

    Planet Boulder Hey, this is a private residence...man Supporting Member

    Nov 10, 2001
    6,482 feet above sea level
    I once had impure thoughts. Oh, and I pluck my ear hair.
    Sorry to dredge this up again, but I wanted to give props both to Jonathan Starr and especially to Pete. Pete hooked me up in a BIG way with a couple of sweet cables he made. They work GREAT and solved the problem. Pete really goes the extra mile and is extremely reasonable.

    I recommend Pete Brunelli to anyone looking to have cables made.
     
  19. fretlessrock

    fretlessrock Supporting Member

    Aug 8, 2002
    Corrupticut
    Thanks for the props and all. You can thank Jonathan twice because he had a working Trace XLR-1/4 speaker cable that he ohm'd out for me so I could be sure that I had the wiring scheme correct. It is Pin 2 Hot, Pin 1 Ground, Pin 3 N/C.

    I had not made one of these before but I found that I could use standard 14/2 stranded, black jacket, speaker cable and made the connections just fine. I had to chop the end off of the XLR boot to get the cable through, but they look and work just fine.

    If you are happy, then I'm happy. Regards.:bassist: