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Running only one side of a power amp.

Discussion in 'Amps and Cabs [BG]' started by Nick man, Dec 6, 2002.


  1. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    Hi everyone!

    In case you havent noticed, Ive been posting alot about poweramps. I keep on running into different problems, and questions, and you guys have helped me alot.

    Do you think you could help me one more time?

    What Id like to know is if I would dammage my amp if I only run one side of it.

    The problem is that I have a 4 ohm cab, and I have noticed that some amps I have looked at run at 4 ohms per channel, or 8 ohms bridged, and I know that running it bridged into the 4 ohm load will dammage the amp.

    I am wondering if I could just run one side of the amp untill I get another cab.

    Any advice?

    Peace
    Nick
     
  2. Stu L.

    Stu L. Supporting Member

    Nov 27, 2001
    Corsicana, Texas
    It'll work.

    Do you already have the amp? If not, you might look for one that (a) can run 2 ohm stereo or (b) at least bridge into 4 ohms. Most amps I've seen will, but this is a small town...
     
  3. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    I dont have it yet, but the biggest reason Im wondering is that most amps that run at 2 ohms per channel or 4 ohms bridged are more expensive than the others. Right now, money is a major factor is my decision.

    Carvin amps seem to have a good reputation andrun bridged at 4 ohms, so I have a feeling I will go that route, but its always good to know I have other options.

    Peace
    Nick
     
  4. redneck2wild

    redneck2wild

    Nov 27, 2002
    Memphis, TN
    If each channel is designed to run at a 4 ohm load you should have no problem running only a 4 ohm cabinet out of a single channel.
    Typically 2 channel PA amps that are designed to be bridged at 8 ohms have 2 separate 4 ohm amps.
    You can also run 1 channel at a 4 ohm load and the other channel at a 8 ohm load without hurting the amp.
     
  5. Nick -
    If money is a primary concern, you should look into the QSC RMX series. They're a little heavier than the Carvins, but I hear nothing but good things about them (word is that Carvin's PAs are pretty good too though), and you should be able to get an RMX from Lord Valve or Life Effects (so I've heard, I've only called LV) for a bit cheaper than a Carvin of comparable power. I'll be getting a power amp shortly too, and I'm definitely going the RMX route...just gotta decide whether to get new or used :)
     
  6. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    Ive considered the RMX amps to.

    Im not sure if the 850 is enough or if I should look at the 1450, but Im considering them.

    Peace
    Nick
     
  7. Shoot the gap man, get the 1850HD. Last time I checked, it was about $440 from Life Effects...similar w/ Lord Valve (Both great guys by the way). Plus, I've tried out a 1850HD that friend has. That is an amp w/ balls. It'll take whatever you throw at it. The one I tried out is used in a smallish PA, and used well. It's something you'll never worry about again. The 1450 would prolly fall along the same lines, you can't go wrong w/ the QSC in my book.

    HTH.
     
  8. JOME77

    JOME77 Supporting Member

    Aug 18, 2002
    Georgia
    Nick,
    I just purchased a new Stewart World 1.6 and running one side only is no problem at all with these amps. The 1.6 and 2.1 allow you turn either both sides on or only one (either side). There is actually a separate switch for each side! The only thing the RH and LH channels share is the AC power source. The Stewart amps sound great too! Plenty of power and light weight.
     
  9. boogiebass

    boogiebass

    Aug 16, 2000
    Second that. I own the 2.1 and it's hard to beat 2100 watts in a 17 pound package. I often use just one channel, too. The separate power supplies make it easy.
     
  10. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    I love the idea of thos super lightweight power amps, but I have to see how much my preamp sets me back before I decide how much I can spend on a power amp.

    Peace
    Nick
     
  11. 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, you can run just one channel of a two-channel power amp. They are designed to allow the two channels to do different things completely independent of each other, such as different signals (as in stereo, biamping, etc.), different load impedances (for example, 8 ohms on one channel and 4 on the other).
     
  12. Fuzzbass

    Fuzzbass P5 with overdrive Supporting Member

    Another ditto from me... I think the dual-mono config is totally cool. I often use just one channel of my 2.1 with the other side powered off; that's nearly equivalent to having a backup amp right there in the rack.
     
  13. Any reason why you wouldn't go with the QSC PLX line? What's the diff?
     
  14. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    $$$$$$$$$$$

    Peace
    Nick
     
  15. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    In case anyone is wondering, the reason I asked is because Ive heard that it is harmful to turn on an amplifier without a speaker or other load hooked up like you might do when going dirrect for recording.

    I think my uncle (who works ALOT with electronics since he worked with Hewlett Packard, and restores jukeboxes, pinball machines, old radios, and old arcade video games as a hobby) also mentioned not turning on the stereo without having speakers connected to both channels.

    So basically everyone (including an industry expert) agrees that there is no harm in using the amps like this, so I wont worry.

    Thanks for the help.

    Peace
    Nick
     
  16. 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
    As long as it's not a tube amp, you're fine. (Some tube amps can be damaged by putting a signal through them with no load attached.)
     
  17. This is the poweramp I use, and I got mine from Lord Valve. Great deal, fantastic amp. A bit more weight in the rack, but I don't care considering the money I saved over a PLX.