when i 1st got my 1st electro amp - the aw75, it was driving thiel 3.5's full-range, w/no problems in the bass output. the thiels are also notoriously hard to drive, especially in the bass, as they employed an active equalizer to obtain flat response down to 20hz. currently, my aw100, which drives the woofer of my monitor, is cut-off at 60hz, as i have a subwoofer system w/a pair of bridged adcom gfa555's driving the subs, so i can't really make an accurate assessment - at least below 60hz. i *do* know that acoustic upright bass sounds like it's *there*, in the room w/ya! ;~)
re: melos, at least according to them, my pre is *not* a hybrid, but all-toob. yes, it *does* have a wery low output impedence - 15 ohms single-ended, 30 ohms balanced. there's a www that's no longer valid re: contact info, but the info on their most recent product is still up-to-date, for those who may be innerested:
http://www.bitstorm.net/sedrick/mindex.htm
regards, doug