If I would be on the market for a new speakers, I would be contemplating Dynaudio Heritage. I'd bet that 866 can drive them with ease and grace. Great system you have there. Artisan Fidelity makes great turntable conversions. I am wondering about your tonearm and cartridge. At your system's level, 301 would be best adored by Glantz tonearm and any Koetsu... Vintage looks to offset 866, but nothing vintage about the sound.
I have an interesting observation to report. At a certain point, all my cables were Nordost Heimdall 2. I upgraded two power cords to Frey 2 (wall to Walker Velocitor and from Velocitor to my amp). Early last year, I tested speakers cables, Heimdall 2 vs Frey 2 vs Tyr 2. Frey 2 was my choice - based on the sound signature, better said lack of it. They were better than Tyr 2 in my system - that difference is best described as more transparency, Tyr 2 had maybe a bit more speed and impact, but it was also audibly darker than Frey 2.
So, it was not about the price, quality, design etc., it was all about loading - or synergy - between amplifier, cables and speakers. Design is basically the same, and just a small difference in specs made Frey 2 speaker cable stand out by making my amp and speakers happier than with Heimdall 2 or Tyr 2.
As your system is quite a bit above mine, I would suggest to try and listen in your system complete loom of Nordost Valhalla 2. IMHO would be appropriate level of an upgrade for your system. "H" is for "honest", not "humble".
