Yamaha A-S2000 and REL-R305

Did you ever get an answer? Love the amp and planning to add a sub, but REL may not work. Too bad.

Here it is; the answer I got from Yamaha Technical Support:
"After speaking with one of your training guys, we found out that it can be done as long as the sub woofer input impedance rating is 100 ohms and above".
I really like the amp and I don't want to ruin it. I need a second opinion, please. Thanks.

Thanks, yes, the REL R-305 portion is clear, however the amp section is where I get confused. The A-S2000 utilizes balanced amp design with a floating ground. Is it safe to use negative speaker terminal and feed to my sub without shorting out the amp’s output? Thanks again.

I'm not sure why you're confused because REL recommends this type of connection. Is there something unique about your system that would prohibit this? If you have the Neutrik Speakon cable, then the hookup should be straightforward: on the bare wire end, 2 positives (red/yellow) and 1 negative (black) connect to the speaker terminals on your A-S2000 (use the same terminals as your fronts if possible), and then the Speakon end connects into the Hi level Neutrik socket on the sub. This is the MUCH preferred type of connection for 2-channel listening. Here's a link to the R-Series manual if you need it: REL R-305 manual