preamp, poweramp, eq

Discussion in 'Amps and Cabs [BG]' started by wizay, Feb 13, 2009.


  1. wizay

    wizay

    Mar 5, 2008
    Norway
    Hi there.
    Im building a small rack, with a Ampeg SVPCL, a QSC GX series poweramp and a graphic eq (a peavey 215 or a dbx215)

    How would i connect those? The preamps output is unbalanced, the eq has balanced ins/outs and the QSC takes both. Im also not sure about what kind of cables to use


    What do you think? Any info much appreciated !
     
  2. vlad335

    vlad335 Supporting Member

    Apr 14, 2003
    Latrobe, PA
    Is there a specific reason you are using a rack EQ? Why not take a 1/4" cable from the pre to the poweramp and use the EQ on the ampeg? Although I am not real familiar with that preamp it seems like it has enough EQ options. Best to simplify your setup as much as possible and add other components based on need.
     
  3. wizay

    wizay

    Mar 5, 2008
    Norway
    yeah im thinking of skipping the whole eq.

    Im using it because im going to use the SVPCL with bass + roll off highs, and another pre with highs+bass rolled off and occasionly distortion on the amp for highs, so i got the lows intact. So i would use a graphic eq to roll of highs/lows
     
  4. vlad335

    vlad335 Supporting Member

    Apr 14, 2003
    Latrobe, PA
    If I understand you correctly, you are using the graphic EQ with one side being a high pass filter and the other a low pass? I take it you plan on going into each side of the QSC with each preamp right?
     
  5. vlad335

    vlad335 Supporting Member

    Apr 14, 2003
    Latrobe, PA
    You may be able to take the preamps outputs into a stereo direct box. http://www.sweetwater.com/store/detail/SDirectPlus/

    Then XLR cables into the EQ and poweramps respectfully. You may run into some gain issues though. Certainly be better than adaptors or custom cables.
     
  6. wizay

    wizay

    Mar 5, 2008
    Norway
    aaa, nice. Thanks for the idea, that could work :)
     
  7. GODSBASSMAN

    GODSBASSMAN

    Feb 2, 2005
    S. Carolina
    I second what Vlad said. That SPVCL pre has plenty of EQ ability and no need for additional EQ. See the following link for Ampeg pdf file.
    http://www.ampeg.com/pdf/SVPCL.pdf
    Peace. David
     
  8. vlad335

    vlad335 Supporting Member

    Apr 14, 2003
    Latrobe, PA

    I see what he is up to... He is actually using the EQ for high pass-low pass filters for use with distortion on the high end. Actually pretty viable albeit difficult to get setup. Has the potential to sound great but if not meticulously tweaked can sound like total ass.
     
  9. vlad335

    vlad335 Supporting Member

    Apr 14, 2003
    Latrobe, PA
    Wizay, what are you using for the other preamp?
     
  10. mr.redpants

    mr.redpants

    Feb 6, 2002
    Philly
    I've been thinking about doing this as well -

    as I understand it, the SDirect would take the 1/4 from the pre out and basically create two identical signals to run to a two channel amp...is that right?
    Red
     
  11. wizay

    wizay

    Mar 5, 2008
    Norway
    Ampeg BSP :)


    Anybody who knows if it will work (level wise) with a DI ?
     
  12. bongomania

    bongomania Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    Well, DI output tends to be either the same level as your instrument, or even lower. There are only a small number of DI's with a higher output level. So the level shouldn't be too high; whether it's too low depends on if the specific DI you're using drops the instrument level too much. The real problem is that DI output is always balanced, and the BSP input is unbalanced.
     
  13. wizay

    wizay

    Mar 5, 2008
    Norway
    What do you guys think about using a crossover?
     
  14. I'd probably go with the crossover. Something like Bass -> Pre -> Crossover

    lows to poweramp channel 1
    highs -> distortion unit -> poweramp channel 2
     
  15. wizay

    wizay

    Mar 5, 2008
    Norway
    i am leaning towards it atm, cant find any unbalanced 1u graphic equalizers.:meh:
     
  16. wizay

    wizay

    Mar 5, 2008
    Norway
    anyone? :)
     
  17. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    1/4" to XLR works fine in the context of a short run in a rack. Longs runs, not so much. Use Tip to Pin 2, Sleeve to pin 3. Jump Pins 1 & 3 on the XLR.

    XLR Pin 1 is ground & Pin 3 is cold. If you get noise, try clipping the jumper - in essence that's a 'ground lift' ...
     
  18. 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.

     
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