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Hartke to QSC connection question?!?

Discussion in 'Amps and Cabs [BG]' started by aniki, Oct 5, 2005.


  1. aniki

    aniki

    Aug 12, 2005
    UK
    Hi all,
    Need a bit of help/advice .
    My Hartke 5000 has developed power amp problems! I know, some will say its hardly unexpected but hey ho.
    I still have a months worth of regular gigs & rehearsals before I will be able to be without it long enough to be fixed.
    Annoyingly its only running on half power & although still 'OK', its not giving the same thunder I got running my 2 ashdown mag410's.
    Soooo, as a quick fix I'm thinking of borrowing a QSC power amp from a friend. Think its a 900?
    Thing is before I say yes to the power amp, I am a little unsure of how to connect it up, or if it will work at all.
    The Hartke has no preamp out, but it does have an effects send.
    Thing is the power amps Ive looked at tend to have 2 inputs and 2 outputs?!?!
    Do I have to use 1 input and change it to mono mode and still use the 2 outputs???
    A little confused. Help appreciated ;-)
     
  2. Aj*

    Aj*

    Jun 14, 2005
    West Yorkshire, UK
    FX Send -> Channel 1 input.

    Chanel 1 Output -> Ashdown MAG cabs (daisy chain). You can then set it to bridge mono mode and away you go, full power into the two cabs (assuming the ashdown cabs can daisychain).
     
  3. aniki

    aniki

    Aug 12, 2005
    UK
    Hey,
    Thanx for the quick reply.
    Ashdown cabs cant daisychain tho :(
    Is there a way round it?
     
  4. Why can't they daisy chain? Only 1 jack on them?

    Also if you run the qsc in bridge mode, make sure the ashdowns are 8 ohm cabs. The two together would be 4 ohms. Make sure the qsc will handle a 4 ohm load bridged also, some do for sure, not sure all do.

    Running in bridged mono, you hook up the banana plug to the 2 red posts, not a red/black combo.

    Otherwise, check the web for owners manual for the qsc, its probably possible to send the same signal to both channels through a switch, patching one channel to the other, or barrier strip. Then use one ashdown per channel, and no problems with no daisy chaining.

    Randy
     
  5. If it is the USA900 model then I do not recommend running in 4 ohms bridged mono. I have had thermal shutdown trying this before. You should set the dip switches on the back to parallell, set the main switch to stereo. At this point either input will operate both channels. Connect one speaker cab to each ouput and presto! :bassist:
     
  6. 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
    Yes, the USA 900 could be iffy in bridged mono into 4 ohms. It may or may not work without current limiting or thermalling (shutting down to protect itself against overheating), depending on the actual (as opposed to nominal) impedances of your loudspeakers, how hard you push the amp, the ambient temperature, et al. Some people do it successfully and some don't.
     
  7. aniki

    aniki

    Aug 12, 2005
    UK
    Excellent, thanks for the advice guys.
    Yeah not having used a power amp before I wasnt aware of the 'parallel' function.
    That sounds perfect. Cabs are 8ohm 450w RMS, so using the pair on the parallel setting should be perfect. TBH it'll never be pushed anywhere near the limit, its just the quality of sound i miss.
    Thanks again :bassist: