REL Subs with H2O Amplifiers

I currently use H2O's Signature 250M (Mono) amplifiers in my 2-channel system.

I have a REL Britannia B3 Sub on the way.

In preparing to recieve and set up my REL sub, I was looking at the owner's manual (on line at http://www.sumikoaudio.net/rel/manuals/b_series_manual.pdf )

Having had a REL Strata-II in the past, I had planned to connect the 3 ends (+,+,-) of the Neutrik cable to the terminals on my H2O amps, as I had previously done with my Strata Sub. However, the B3 owner's manual recommends connecting the black ground wire to the preamp when being used with "Differential Output Amplifiers."

Because of the set up in my listening room, (power amps are not near my preamp) spliting up the 3 cables that make up the Neutrik connection will be a headache.

I have contacted Henry at H2O and he is looking into this for me.

In the meantime, is anyone using a REL sub with H2O amps? If so, what wiring configuration are you using? Are you running all 3 wires to the H2O amp, or are you connecting the black (-) to your pre?

From my past experience with a REL sub, I absolutely want the sub to get the signal from the power amps via the Neutrik connection.

Thanks