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Linking two sides of a stereo power amp...

Discussion in 'Amps and Cabs [BG]' started by White_Knight, May 12, 2001.

  1. White_Knight


    Mar 19, 2000
    Quick question for all of you: is it possible to link both sides of a stereo power amp (an Alesis RA-100 in this case) to a single cabinent? The RA-100 doesn't have a mono/bridge mode - stereo only. I wouldn't think that it would be possible, but is there a way? Basically, I'm looking at running the RA-100 into a 15" cabinent as a slave amp off of my main stage amp. Thanks in advance.
  2. mchildree

    mchildree Supporting Member

    Sep 4, 2000
    It may be possible to do some mods internally like on the old Crown Microtechs, which had to have a jumper installed on the circuit board...but before you do this, you want to check with Alesis. I'd say there's a good chance you'd void your warranty. The manual doesn't discuss this at all? I've seen other amps that were non-bridgeable simply because there's a minimum impedance they recommend.
  3. When you bridge an amp, you'll have twice the power on twice the load impedance. For example a 2x100 watts 2x4 ohms amp will be, bridged, 1x200 watts at 1x8 ohms.

    In order to bridge, you need to connect the inputs together and put one channel in counterphase, by adding an analog inverter (one opamp IC and a few resistors and capacitors). Then connect the speaker to the + terminal of both channels. If you're not sure what I'm talking about, them please don't try it. If you're lucky, the amp will have a jumper inside, like Mchildree said, but I really doubt that. If there is a bridge jumper, why wouldn't they have put it on a switch on the back of the amp instead?

    Hope this helps.
  4. White_Knight


    Mar 19, 2000
    Thanks all. Joris, I do understand what you're talking about but I think I'll just leave it alone for now. It just seemed that I would be wasting some power that might be put to good use if there was a way to link the two channels.

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