I had a very limited time to listen to the Technics SE-A5. Comparing it with my ST70, my initial impression is it delivers more details, especially in the mids and highs frequencies. The bass is likewise tighter. Maybe because of the 120 watts per channel power it packs.
However, the st70 is still "mas mataba", although the difference is that that big. The ST70, moreover, delivers a warmer sweeter sound.
I like st70 for music that are more laid back (jazz and standard), and the Technics for music that are livelier (rock and pop). The Technics maybe more versatile.
For me it is still too early for me to tell which amp I prefer, I hope that his helps.
Gears used:
Preamp: Dynaco Pas 3 Preamp
CDP: Onkyo Liverpool (surplus)
TT: Technics 1200 Mk 2 (courtesy of Blondie)
IC: DIY silver interconnects
speaker cables: Monster cables (I do not know the model)
speakers: Boston Acoustics T830 (floorstanding)
Monitor Audio Bronze 2