Howard: I have the McCormack RLD-1 preamplifier also, just like you (with the DNA225 Power Amplifier, both of them recently upgraded to Platinum Edition by Steve McCormack) and I am also thinking on Dual Subwoofer. Why are you running your subwoofer from your amplifier instead of using the RCA at the back of the RLD-1 preamplifier ? is there any acoustic advantage plugging the subwoofer at the back of the amplifier instead of going from the preamplifier ? you could use the right chanel for one subwoofer, left channel for the other subwoofer. By the way, I am considering Dual SVSound PB12 Plus/+2 or a single PB12 Ultra + 2, what do you think is the best option ? My speakers are Ambience Superslim 1800se Ribbon speakers and the rest of my system includes Metronome Signature Transport and d.a.c., Acoustic Signature Final Tool Turntable, Magnum Dynalab MD100TR Analog Triode Tubes FM Tuner, with high-end power cords, interconnects and speaker cables. Looking forward your comments. Best, Antonio Machado.