Bridge Class D stereo amp to mono?

Discussion in 'Amps and Cabs [BG]' started by Deleted member 165050, Apr 21, 2018.

  1. Serious but dumbass question... can I bridge a Class D stereo hifi amp to mono by linking - speaker out terminals and connecting a single speaker to the + speaker out terminals? Amp is an SMSL SA-50.
     
  2. Wait for around the first week in July. People are more tolerant of fireworks around then.
    Never good to hook the output if two amps together.
    If the amp is designed for bridgeibg then bridge it, if not, not.

    You can link the inputs together though, making it a dual mono amp.
    Then hook speakers to both outputs as you would normally.
    Will have the same audio affect without the smoke release.
     
  3. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    With a single speaker, dual mono isn't going to work.

    Often, class d amps can not be bridged, depends on the output topology.
     
    BassmanPaul likes this.
  4. I contacted SMSL who replied very quickly, saying their amps can't be bridged. Now I know! Neat little amps though... I guess for my application I will use one channel to drive the single speaker but put a dummy load on the other.
     
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  5. BadExample

    BadExample

    Jan 21, 2016
    Injiana
    You can probably skip the dummy load.
     
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  6. Al Kraft

    Al Kraft Supporting Member

    May 2, 2016
    Northern Virginia
    The smartest and most appropriate first step when you have a question about a manufacturer's equipment that so many people either miss or dismiss in favor of internet folklore - textbook smart approach here IMO!
     
    ficelles likes this.
  7. I wasn't sure about that (even though I will only use one channel) but as I have an 8ohm 100 watt resistor handy I though I might as well be safe...
     
  8. mmbongo

    mmbongo I have too many basses. Supporting Member

    I would contact them again and ask them about the dummy load, not sure why you'd ever do that. Does the manual say to connect a dummy load?
     
  9. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    Why a dummy load?
     
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  10. Paranoia about plugging into the wrong channel...
     
  11. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    Doesn't matter
     
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  12. beans-on-toast

    beans-on-toast

    Aug 7, 2008
    Usually amps that can be bridged have a switch to do so. It’s a feature.

    Since you can’t bridge the output, consider connecting two stacked speaker cabs to the outputs and bridge the input.
     
    Last edited: Apr 23, 2018
  13. That would rather defeat the requirement of running into a single speaker :)
     
    beans-on-toast likes this.
  14. That's good to hear, I had read somewhere there was a potential overheating issue with Class D if running into no load but I guess that would only be with extended use anyway...
     
  15. beans-on-toast

    beans-on-toast

    Aug 7, 2008
    Being constrained by requirements can be counterproductive when pursuing the best sound.
     
    BadExample likes this.
  16. I'm actually pursuing a way of driving a single speaker with an amplifier designed for two speakers. Perhaps that wasn't clear enough in the OP.
     
  17. beans-on-toast

    beans-on-toast

    Aug 7, 2008
    It was clear. Just thought that another approach might be acceptable.
     
  18. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    I would not recommend doing this at all. You have no idea what the internal topology of the output stages are. Under some conditions it could destroy the amp, under other conditions there will be zero increase in voltage swing or power. You can not possibly know which case you are dealing with until it's too late.

    You need to read up on the different output stage topologies before making suggestions like this IMO.
     
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  19. Al Kraft

    Al Kraft Supporting Member

    May 2, 2016
    Northern Virginia
    I'd be very surprised if any commercially available class D or class AB solid state (including hybrids with a tube pre-amp) heads/amps had any life related issues associated with running with no load.
     
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  20. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    In general, another urban myth perpetuated by those who have no idea what they are talking about.

    With a properly designed class D amplifier, there is absolutely no problem with operating unloaded.

    I'm sure there are horribly designed class D products out there, I am not familiar with them however