Mainstream Phono Stages Incorporating Premium Branded PCB Parts - Do They Exist?

Yes, it was aa Audio Note capacitor used in lieu of a Western Electric paper in oil.  It’s hard to believe, but there are much more expensive capacitors sold by Audio Note.  Deja Vu uses what works for their sound, so the parts mix includes crazy expensive parts and very cheap parts, and even parts that are old and test bad but sound good (e.g., old vintage caps with high DC leakage which is not relevant in crossover usage).  
 

A customer with multiple Deja Vu custom-built systems was fuming mad because some very cheap look binding posts with ugly plastic covers over thin and tiny brass metal fittings were installed on a very premium amplifier.  The customer insisted on something “better.”  Vu was tempted to not allow the customer to buy the amp because he was unworthy of such an amp (Seinfeld Soup Nazi: “No soup for you”), but compromised when he found some nice looking and not too bad sounding binding posts (something like WBT pure silver binding posts).  I heard a great sounding system there that had a vintage field coil driver that now sells for more than $30,000 per pair matched with $100 tweeters; its all about the results. 

I used to frequent the store on rte 123. Vu is a nice guy. But his shtick (tube SE amps driving hyper-efficient electromagnetic speakers)and my shtick (OTLs with ESLs) are very different.

He used to have a Russian guy who built those custom SE amps.

Because the builds can be for a specific customer’s needs, there are some quite odd pieces out there, like a single chassis holding a phono stage and crossover.  This reminds me of an establishment in the M.A.S.H. novel: Finest Kind Pediatric Hospital and Whorehouse.

I have a custom built linestage by their Italian builder that has a transformer output that is intended to match with the transformer inputs on my amp which is a copy of a Western Electric 133 amp; my amp has original Western Electric input and output transformers.  Many of the other parts are vintage as well.  The big challenge with this sort of build is finding matching parts, particularly because the only way to know that a part is good is to try it in-circuit.

Great design and tightly tolerance parts are the key to higher performance.

One afternoon at DeJaVu Audio, I listened to a pair of Audio Note speakers, I think their model E, if that makes sense, being driven first by an AN Kegon amplifier (for sale then at ~$125K) and then by the AN Ongaku (probably around $80K). This was at least 20 years ago, so maybe prices are higher now if those amplifiers are still in production. Anyway, they both sounded very good, but there was a distinct difference between them having to do with tonal balance. I cannot recall exactly how they differed in their presentation of music on a speaker presumably designed to accommodate both, but my thought was if there is such a thing as "perfection", ought these two amplifiers to be nearly identical in sound quality? Anyway, if expensive parts per se are the way to Nirvana, surely AN products ought to be on the way.