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Noob preamp to power amp question.

Discussion in 'Amps and Cabs [BG]' started by atomic_turtle, Feb 15, 2004.


  1. atomic_turtle

    atomic_turtle

    Jun 22, 2003
    Dracut, MA
    Ok I need a recommendation. I have a Ampeg B2R head running into a SWR Goliath Senior Cabinet (6x10, 4ohm, rated 1000w RMS). I have a feeling I need more power and would like to use a QSC power amp and for now use my B2R as a preamp to the QSC. I'm planning on a QSC RMX850 bridged mono or a QSC RMX1850HD bridged mono for this cab.

    Here are the noob questions.
    1. What cables do I need to hook up the pre to the power amp? Will my Speaker cable (monster cable 1/4" jacks) be suficient to do this?

    2. What cables would I need to run the QSC amp in bridge mono and to connect to my speaker cabinet.

    Thanks for the :help: in advance. :bassist:
     
  2. Trevorus

    Trevorus

    Oct 18, 2002
    Urbana, IL
    Check the manual for the QSC. I think the RMX's need some special cable for bridge mode. To hook the Ampeg up to the QSC, you need either 1/4" cable or XLR to hook the line out from the ampeg into the line in on the QSC.
     
  3. todd 4ta

    todd 4ta

    Apr 3, 2003
    Indiana
    I looked at the back panel for the B2R and you have two options for connecting to the QSC RMX power amp. If you're not using the XLR output on the back of the B2R for a DI, I would recommend using that set at 'line level' and using an XLR to XLR (regular mic cable) to go from this XLR out to the balanced XLR channel 1 input of the RMX.

    If you are using the DI, then just use a 1/4" to 1/4" patch cable (not speaker cable) to go from the preamp output to the 1/4" unbalanced input on the RMX.

    For bridged mode on the RMX, set the switches correctly, then you must either used a correctly configured Speakon connector (the manual has the wiring required, very easy to change with a screw driver), or you can use a banana connector in the two outputs for bridge mode.

    If your cabinet has Speakons, I would definitely go with Speakons. If not, you will need a cable with one connector for your cabinet, and then choose either Speakon or banana for the amp. Again, I would recommend Speakon for convenience and safety.

    I have 'bridge' speakon cables, some with a speakon cabinet connector and some with a 1/4" connector so I can use with any cabinet that shows up. I wrap a piece of blue electrical tape around the 'amp' end of the cable and write 'bridged amp' on the tape so it doesn't get mixed up. (The amp end is wired differently than the speaker end on the bridged cable).

    I also have other 'regular' speakon cables to use for 'non-bridged' connections.

    Good luck, it's actually much easier than it sounds once you have it in front of you. Download the RMX manual from QSC's website and read through it if you haven't already. One of the best technical manuals out there (thanks Bob!).
     
  4. atomic_turtle

    atomic_turtle

    Jun 22, 2003
    Dracut, MA
    Sweet! Thanks for the input. My Cabinet does have speakon jacks and I think that is what I will use to connect the QSC to the cabinet and for now I think I will use an XLR cable to connect the B2R to the QSC. Thanks again I just needed the reassurance to do what was right. Oh and I did manage to find the QSC manual on the website which proved helpful in setting up the amp to run in bridged mono mode.
    THanks! :hyper: