Splitter on gpa 555!pre amp output

Thank you this helps tremendously. Now I am trying to remember about the 2 Polk SDA 2Bs. I think the hifi store I bought them from sold me a different interconnect cable that connects the two speaker to each other after I bought the second amp. I am not sure but think the interconnect cable for running two mono amps has a box on one end. Would you happen to have knowledge of this also?   Called Polk but not any help….30 years very hard  for me to remember!! Any help is greatly appreciated.

So I removed the inner connector cable and it has a box on one end saying

“polk Audio SDA Non-Common Ground Amplifier Interface”

Does anyone know if because I had two GFA 555s bridged it causes a need for a non common ground cable?

Thanks

Does anyone know if because I had two GFA 555s bridged it causes a need for a non common ground cable?

Yes, If you use the original interconnect cable to connect both Polk SDA 2B together while using two bridged GFA 555 to power the speakers, it may damage your amplifiers! That's why you need the SDA Non-Common Ground Amplifier Interface.

If you using only one GFA 555 in stereo to power both speakers, it is safe to use the original interconnect cable.

Thanks! Appreciate that! Polk customer service sucks for old stuff. Sounds like their in a rain forest country. Calling Adcom just want to sell me a different amp! Wtf