jsautter, fair points, good comments. I wish I could get my hands on more overseas components, but it’s hard to review, recommend a product that does not have a distributor in N. America.
Ha, I was presuming initially that you were discussing Berning amps, not preamps. Now, I see that you were probably referring to preamp. Yes, there can be very wide differences between preamp designs. I have heard shocking differences between brands and models of preamps. So, I get your strong preference in that regard.
If you attempted to pair the Pass preamp with the VAC Phi200 I very much understand if you did not care for it. I would not think the two would be ideal. Manufacturer’s house sound plays a huge role in matching gear, and some combinations are simply not ideal, whereas others are seen as heavenly.
Nice looking speaker; I presume you mean the M5 passive. Well, that’s 8 Ohm, 91dB, so yeah, 110 watts is plenty. It’s been several years since I worked with the VAC Phi200, and having been through many more amps, there is more in terms of resolving power and depth that can be achieved if you wish, and you could go either with a second unit in mono or move up the line if you chose. Moving to another brand of amp would open up the "can of worms", however, another amp I can recommend that would provide some variety with similar tonal palate would be the Wells Audio Innamorata. If you adore the sound, getting a second Phi200 and going mono would be a big bonus. You have room to roam in terms of improvements. It would make your speakers seem more formidable and refined at the same time. It’s also important to try different power cords with the Phi200. :)
You have a very fine system, and it is at a level where the changes will reveal very strong, distinct characteristics. No wonder you feel strongly about the matching. I get that. We tend to anchor to our "prime component" and work off of it. The direction one takes with a different brand is either going to be horrid or heavenly. So much depends upon synergy between brands/models, cables and speakers. I have had a few preamps, amps, etc. that were not impressive with one speaker work stunningly with a different speaker. If you heard it with the first, you would say it is overrated, while hearing it with the second you would say it is sublime.