Line up:
Benchmark DAC1, Bel Canto DAC2+, Grace m902, Sony SA5000, and Sony R10.
Looks like the mods to the Bel Canto DAC2 have tightened up the bass to be more than a match for the Benchmark. However, Iron_Dreamer and I did hear in a few songs where the lowest octaves were a tiny bit more pronouced with the Benchmark DAC1. Of course I could only hear it with the SA5000. The soundstage of the Bel Canto DAC2+ was a bit wider but was more up front and wraps around more, the shape of the soundstage, that is. The Benchmark had a soundstage that was a bit further back, but more flat across when listening from left to right.
This was my first time listening to the SA5000's. I was impressed. Funny thing, is that if I could sum up my opinion of the SA5000, it sounds the most like somewhere between the Sennheiser HD650 and the Sony R10's.
The R10's still have more detail and tighter imaging, but the R10's simply do not go as low as the SA5000's do. The SA5000's have fantastic subterranean bass. Without a doubt, the SA5000's would be my #1 choice for Electronic music. Yet, they are detailed and have a nicely shaped frequency spread. I liked them for all other genres of music as well. I found them to be very balanced in sound, unlike their predecessor, the CD3000.
While not as comfortable as the Qualia's, the headband is weird. I put it right on the top of my head, and the metal parts just dug into my head. But tilting it back, and it rested nicely. But this did place more pressure on the ears. While the clamping pressure is nowhere near that of the K1000's or even the HD650, it is significantly moreso than the R10's and CD3000.
-Ed