I purchased a pair of M-300 mono blocks from a Belcanto dealer, to play a pair of standard Maggie 1.6QRs, through a Rogue 99 Magnum pre-amp, using Millersound bi-wired speaker cables. The amps would not work; when powered up, they simply let out a radio frequency type squeal, and their protective circuitry shut them down. I have friends who make their living in the high end audio industry, and they could not get them to play squat. I finally had Belcanto ship me a new pair and I returned the original amps. Naturally, they played perfectly in Minnesota, but once again the new amps would not make music in Pennsylvania. It was the most frustrating thing. The dealer contacted Rogue, and Maggie, and everybody had their two cents worth of ideas, but nothing helped. The M-300s just did not like the load the Maggies represented, or, the amps lack adequate RFI rejection design. No reason on this earth why they should not have played. Belcanto continued to claim no-one else had ever had the problem with these units, but I am told that is highly unlikely. They did play on an old pair of Boston Acoustic speakers and sounded fine at that, but they represented a rather benign load.
We tried bi-wiring; then I put jumpers in place and ran single speaker wires, but nothing would get those amps to play. Then a friend loaned me a pair of Nuforce 9's, and they sounded great, playing the 1.6QRs effortlessly. I have no idea why the M-300s would not work, but people in the know feel it is an RFI problem. I even took an old Sony CDP 707ES with a variable output, and ran it directly into the Belcanto amps, circumventing the Rogue, and still, nothing.
Just thought everyone should know to be careful, especially if they have speakers which can drop to below 4 ohms while in use.