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Head, Power amp (putting the pieces together)

Discussion in 'Amps and Cabs [BG]' started by MuzikMan, Apr 2, 2004.


  1. Hi everyone, I've been enjoying the wealth of knowledge and opinions in this forum. Now it's time for me to call the experts.

    I want to run a head and power amp together.
    I don't want to damage my gear!

    I have an Ampeg B2r, Hartke Mx 410, Avatar B115. Pretty good sound. Gets me to the gigs, but a little lacking in power. I need to push it to the limits to be heard in the loud rock band I'm presently with.

    I recently aquired a Berringer MDX2200. Put it through the effects loop. Not clipping like I was, but still no headroom.

    Today I received my latest purchase. A used QSC USA900. This is my current configuration.
    Bass--Ampeg--effect loop--Ch1 compressor--Ampeg--4x10
    --------------pre amp out--Ch2 compressor--QSC(bridged)--115.

    I like the fact that I can balance the two cabs with the Ch2 output knob.

    No problem with volume now, but what about the Ampegs safety?
     
  2. I hope I wasn't offensive or extremely ignorant. I was wondering if my question doesn't fit the format of this forum or if it seems foolish to ask?
     
  3. metron

    metron Fluffy does not agree

    Sep 12, 2003
    Lakewood Colorado
    Im not sure I understand how you have your amp connected. Is the Behringer a compressor? I would use that only if you need it. What I would do is run the preamp output of the Ampeg into your power amp in bridged mono mode. I would use one speaker most of the time and add a second if more volume is needed If your speakers are the same impedance then you should not have a drastic volume mismatch if you use them both at the same time. Hope this helps.
     
  4. yes your post is helpful. I guess that would be a much simpler setup than the one I arrived at. To break it down simply I have the 410 comming straight out of the head and the 115 comming from the QSC power amp from my pre-out. I was attempting to push more power for the lower frequencies. This setup works but I'm not sure if it is safe to run the heads power amp and pre-out at the same time.
     
  5. metron

    metron Fluffy does not agree

    Sep 12, 2003
    Lakewood Colorado
    Its ok but I think its more complicated then it needs to be. Try the setup I suggested and see if you like it. If you are using a compressor too use that first:

    compressor > ampeg preamp out > power amp in bridge mode > speaker

    I think you might like that better. Besides do you ever need both cabs? I use a 210 most of the time and Ive never played in a place where it wasnt enough. Good luck! :bassist:
     
  6. I will absolutely try the simpler approach. I am probably overanalyzing everything like I tend to do. Thank you for assuring me that I am not about to blow up my rig though.
     
  7. Thanks for the advice metron. Simpler is definately better. I've tried a slew of different setups with interesting results. My best scenario at this point is pre out--power amp--speakers. I ditched the compressor too. When I unplugged it I noticed it was robbing some of my tone even in bypass. I was simply thinking too much about my setup. Thank you very much for reminding me that complicated doesn't mean better.

    I only have one more issue to settle. It seems that my head clips before my power amp. I can only assume that means I can't get a strong enough signal to the power amp. Time to go shopping for a pre-amp I think!!
     
  8. metron

    metron Fluffy does not agree

    Sep 12, 2003
    Lakewood Colorado
    Glad to help. I think that compressors should only be used if they are very necessary and should be of the highest quality.

    Now do you mean that the power amp is clipping? If so then the signal is too strong and you should turn down gain on the pre. If the signal from the ampeg is too weak then your amp would not clip. I think you should have adequate gain though. I think a new pre would be a good idea just because you can trim size and weight from your setup. If you are looking for something similar to your B2 then a used SVP-PRO would probably do the trick.
     
  9. Well it sounds more like the QSC has more (and it should) headroom than the Ampeg. You'd do better to let the QSC power both cabs and just use the ampeg for its' pre-amp. That way you'd be using about 1200 watts ( the USA 900 is 900 watts into 8 ohms bridged! and will run at 4 ohms bridged!!! (heck of an amp))
     
  10. You guys are awesome. I really dig the info.

    The B2R is clippin with the QSC not even breaking a sweat.

    I am currently shopping for an SVP pro.

    I didn't know you can bridge at 4ohms. I thought that when you bridge 8ohms each side of the amp is reading 4 ohms which I understand to be the limit of this amp. I do understand that the given specs are safe limits but if bridging at 4ohms has been proven effective I will most definately try it. Very interesting.................
     
  11. Metron made a good point earlier in this thread about cabs. One should be enough but right now I feel I need both for the proper tone. The Hartke MX 410 does best when the Avatar 115 helps with the low end.

    Really thinking about a couple Aggie GS112 or Avatar SB112.