Power amp wiring/usage question, PLX

Discussion in 'Amps and Cabs [BG]' started by troll, Nov 14, 2004.

  1. troll


    Aug 31, 2000
    Chicago area
    Does anyone know the specifics regarding the wiring of the PLX or QSC amps in general?

    We have the option of speak-on and banana out, per channel, ok fine. BUT, can we use these together to increase the load on the channel? Or are we stuck doing it in the cabling via one output or the other? I haven't been able to find any of that in the manuals or their site. And I'm not near the amp to break out the multimeter to do any testing.

    Has anyone run them in this fashion and/or is it possible?

    I currently run one channel 2 ohms via a custom speak-on to two 1/4 cable I made for one cab (4 ohm, two inputs) and another at 4 ohms straight in.

    I want the flexability of running another cab (2x10 probably) off the other channel when needed for that extra volume or remote monitoring on stage, for me, or anyone else that wants it, like the drummer... Sure, I could just make another cable like I had, but if I had the ability just to throw a banana cable to that other out on the fly and run with it, that would be great. I just don't want to fry anything.

    Hope this makes sense :)

  2. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    i dont know plx specifics but the amps i've used with multiple outs per channel have always been able to have all the outs used at once regardless of type (unless a particular out is to be used only in bridge mode)
    i don't think using a speakon and a bananna cable at the same time on the second channel is an issue, but ask bob lee to be sure
  3. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    You should be able to use both simultaneously...but make sure you don't go below 2 ohms per channel.

    Also, be careful with phasing as it's easy to reverse the banana plug without knowing it. Having cabinets out of phase will make your low end go bye-bye...
  4. DubDubs


    Aug 23, 2004
    Los Angeles
    The wiring is on the back of the unit and in the manuel. For bridged mon it's +1 +2, and for parallel it's +1 -1 for channel output 1 and +1 -1 for channel 2 output. If you want to run both channels with one output it's +1 -1 for the first channel and +2 -2 for the second. Hope that helps.
  5. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    The banana and Speakon outputs are in parallel, and using one doesn't switch the other off or anything like that.
  6. chucko58


    Jan 17, 2002
    Silicon Valley, CA, USA
    I paid for all my gear myself. Well, me and MasterCard.
    What Bob said. I've had occasion to use both the Speakon and banana jacks for the same channel of my PLX 2402 at the same time, and it works fine. This was usually when doing something foolish like speaker testing, powering both of my Acmes on one channel, and a borrowed El Whappo on the other... in my living room. (It sounded amazing, BTW!)