On a related note, the Berning MicroZOTL is a superb headphone amp, which can and does double as flea-powered amp for ultra-high efficiency (100+ db) speakers. If matched up right it actually does a very nice job as an amp. I was really impressed. Don't even bother if your speakers are below 100db effifiency, so you're SL3's are out of the running. Highly recommended if you do get a head amp.
Marco
Marco