TomDac
former MLO owner/operator
Slightly left-field wrt most of the comments in this thread, but I've just had a revelatory experience with amps for my Spires. I'd started with bi-amping from my Arcam AVR20 receiver and the sound was excellent - great staging and transparency, but perhaps just a little harshness in the vocals and 'brassiness' in piano and some strings (although room tailoring is still under way). So I swapped in a mint Mark Levinson 331 (recapped) and everything took a step forward - clarity, transparency and staging all improved, with great refinement and delicacy. Which would have been fine, but I'd also recently bought, for our 'analogue' music room system, a pair of Michell Alecto II monoblocs, with the additional MOSFET upgrade by their original designer, Graham Fowler at Trichord Research. On a whim, I swapped these in to the main system, and was blown away - staging was bigger, deeper and more involving, bass control was superb and, above all, they had that elusive 'musicality' that has your toes tapping in all the right places. These amps are as rare as hen's teeth but, in 20 years of Martin Logan ownership, these are the best amps at anything approaching a reasonable price that I've come across for them.
Just love this post. It really is amazing when you upgrade and the differences are so noticeable!!