While the Transcend and Special SE's have enough guts to drive most speakers (even my older 89 db 1W efficient speakers), I'm still thinking that careful design of a single-chassis push-pull amp that has less to the signal path can be the answer to lower sensitivity speakers. I'm working out a couple of proto-types currently, and so far- the results are very good! I've got a set of KT88's being driven from a LTP 6SN7 with a single 6SN7 gain stage in front of it. Listening has been on-going for about 10 hours now and I'm so far not wanting to change a thing! Best, Aric