Jeff Rowland with Rel sub

I got noise(pop) and hum, but nothing fried. I am hooking to the speaker terminals as per instructions in the owners manual.

When connecting a REL to a differential amp using the high level input (the best choice for 2 channel music) you must ground one of the positive wires of the the supplied Neutrix connector to the amplifier. I believe the configuration is red positive to ground, yellow positive to positive amplifier speaker terminal and black to the negative amplifier speaker terminal for the same chanel (either left or right) you have chosen to connect the positive lead to. Double check the configuration; it should be in the owner's manual. Not sure if the Rowland is a differential, but I hope this info can help aleviate problems people may have hooking up their RELs

Its not clear to me how you're connecting, but I'll comment on what works for me...

With my Ayre V-5x (balanced differential), I use the high-level unbalanced input on the REL. I connect the yellow wire to Left+, the red wire to Right+, and the black wire to a chassis ground screw on the amp.

How are you connecting?

I connected according to the directions in the owner's manual: FIG 2 unbalanced high level input at the sub. To the amp: red to right positive, black to right negative and yellow to left positive. Todster, I tried your suggestion and got nothing.

I am currently using the Concerto Int. with a REL B-3 sub connected via the Neutrix interconnect. Fabulous results.