Audio Research Corp Ref 5 SE

It is important to note that ARC stresses that the updated Ref 5/5se's will be identical to a newly manufactured 5se in every way, zero difference. As a current Ref 5 owner, I am happy with this.
Also, regarding the usual silly comments that ARC is always updating products, the facts are that they generally go five years between new models. The ref 5 is less because the unit was already a very fine piece that benefits greatly from an even stiffer power supply and new capacitor materials, and is a fairly simple update. I applaud them for making the update available.

Well, I have to tell you, at 300 hours, it is NOT broken in. You will still undergo noticeable improvements. I also owned a Ref3, and then Ref5, and now the 5se. It is after the 500-600 hour mark that the benefits are most apparent. Yes, prior to that, it is marginally better than its predecessors. But after about 600 hrs, it is noticeably better, imo. You really can't make these judgements yet as to where it will end up.

I know it is hard to believe, but I actually found the improvements from 500-600 hrs. to be fairly profound. Up until the, maybe, 300 hour mark, it just did not breathe as freely. It sounded a little constrained. It required a 20 minute warm-up to sound its best. I am now at 780 hrs, and it sounds better in five minutes than it used to in 40. Just more open, relaxed, transparent, free breathing, effortless, and musical. Less mechanical, if you will. Now, that said, if you don't like the sound at 300 hrs, you will likely still not like it at 600. I also have a Shindo preamp and enjoy that also. They are different, and have different presentations. I appreciate both. Would I want one with the best aspects of both? I doubt it. I like the contrasts, and the different insights they both bring.