Best way to drive balanced input from SE preamp

I just acquired a Bel Canto Evo2 Gen 2 amplifier which I'm using it in stereo mode, driving it with my ARC LS16 preamp. I'm thinking about getting a second Evo2 to use in a monoblock configuration with the first one. When doing this, both amps must be run in full balanced mode. Short of getting a new preamp, something I will evnetually do, How can I best make the adaptation from the SE preamp-out to the balanced amp-in? I'm assuming the $30 Radio Shack adaptor for doing this is not an option in terms of sonics!

Peter