Chiming in late here, but would like to add that I have a SIT-3 that sounds wonderful with my Maggie 1.6. Of course, I do not listen very loudly but at moderately high levels (guesstimating 90-95 dB) the SIT-3 sounds significantly better than my former 400 WPC Bel Canto Ref 500S. Currently, I mainly use my Maggies with a 250 WPC McIntosh MC252 and don't appreciate any loudness or dynamic differences and in fact would ultimately prefer the First Watt.
In OP's case I would audition the Pass Labs XA25 to replace the SIT-3. I also had that amp and would switch back and forth between it and the SIT-3. The XA25 sounds similar but plays louder at 20 dB gain. It also opens up an easy trade-in option with Reno HiFi.
In OP's case I would audition the Pass Labs XA25 to replace the SIT-3. I also had that amp and would switch back and forth between it and the SIT-3. The XA25 sounds similar but plays louder at 20 dB gain. It also opens up an easy trade-in option with Reno HiFi.