Common ground

I am looking at two options for powering SDA 2B’s: an Adcom GFA 555 or two bridged GFA 6002’s. I’m assuming the 555 is common ground, but what about the separate amps? Full disclosure: I have no clue what common ground really means, so if you feel inclined to explain it, pretend you’re explaining it to a child lol

Comments

  • Legender
    Legender Posts: 478
    Little searching and reading on your part may be needed.
    Check out this prior thread. Google search is your 'friend'.
    http://forum.polkaudio.com/discussion/152246/the-old-common-ground-issue
    Music: Oppo103 - Parasound JC2 - Parasound A21- SDA 3.1
    Theater: Denon 3808 - B&K 7500/Emotiva XPA-3- RTi12, CSi5, RTiA7x4, PSW505
    Sleeping: Marantz 70005 - Harman Kardon 2400 - SDA 2
    2 Channel: Cary 306 SACD - Canary Audio 906 - Pass Labs x250 - PS Audio Perfectwave DAC, Polk LSiM705, SVS SB13 Ultra
    Office: Dell Optiplex, Emotiva XDA-2, Adcom 5500, LSiM 703
    Spares: Yamaha CA-810; LSi 15; Kenwood Basic M2a, Yamaha M60/M80, Polk Monitor 7, SVS SB13 Ultra
  • [Deleted User]
    [Deleted User] Posts: 7,658
    Unlike "regular" speakers which completely isolate the left and right audio negative connections (the black terminals on your amplifier) the Polk SDA speakers connect them together. On the majority of amplifiers this isn't a problem since the amplifier has already connected them together inside the chassis. But some amplifiers are designed differently, these designs do not connect their left and right negative terminals together and as a result could be damaged if they were.
  • AdamSDCA
    AdamSDCA Posts: 18
    GFA 555 purchased, installed, and playing :smile: Now once the RD0 backorder catches up, I’ll be all set!
  • honestaquarian
    honestaquarian Posts: 3,186
    Unlike "regular" speakers which completely isolate the left and right audio negative connections (the black terminals on your amplifier) the Polk SDA speakers connect them together. On the majority of amplifiers this isn't a problem since the amplifier has already connected them together inside the chassis. But some amplifiers are designed differently, these designs do not connect their left and right negative terminals together and as a result could be damaged if they were.

    @KennethSwauger this is likely THE BEST explanation of the common grounding issue that I have ever seen. Kudos!! :)