@demoiree
I have been using mine with the Supratek Chardonnay and the only issue I had with it going into fault mode was with the 5AS4 fast start-up rectifier as opposed to Mick's recommendation of the 5AR4 whose slow start up doesn't cause the EX-M7 issues. Other than that I haven't had any problems and I don't really push the combination much past the mid-80's db mark. I checked with Mick at Supratek before I bought the EX-M7 to see if I could expect any problems and even though he is not a fan of direct coupled amps he assured me there would be no DC problems. I also have a PS Audio BHK preamp and a fully upgraded Sonic Frontier Line 2 SE+ but I haven't tried them with it yet. Both are fully balanced so not expecting a problem but you never no until you try.
I have been using mine with the Supratek Chardonnay and the only issue I had with it going into fault mode was with the 5AS4 fast start-up rectifier as opposed to Mick's recommendation of the 5AR4 whose slow start up doesn't cause the EX-M7 issues. Other than that I haven't had any problems and I don't really push the combination much past the mid-80's db mark. I checked with Mick at Supratek before I bought the EX-M7 to see if I could expect any problems and even though he is not a fan of direct coupled amps he assured me there would be no DC problems. I also have a PS Audio BHK preamp and a fully upgraded Sonic Frontier Line 2 SE+ but I haven't tried them with it yet. Both are fully balanced so not expecting a problem but you never no until you try.