As a result of Onhwy61's comment, I went "phono in" on the interface. After encountering a "hum" problem that required a complete disassembly and new modification, I'm back.
"Santana Abraxas" is the test record. I bought this record in 1971, this is my third copy; the record I'm using is new. To say I'm familiar with this record is an understatement. I played this at a high end emporium using Sota, Arc electronics and top of the line Thiel speakers, that's what I'm going to be comparing today's results with. The cover on this album is the most provocative I've ever seen, you can check it out online.
"Singing Winds, Crying Beasts" is the first cut, it's also my favorite. These "tinkly" chimes test a systems resolution like you wouldn't believe. I'm going to enjoy the music and give you my conclusion later.
While listening to Santana I could see faces and places flash before my eyes; head shops in Chicago, events that lasted for three straight days in the park. That was a time when everything was "cool and groovy"; it was "The Age of Aquarius", those were the days my friend, I thought they would never end. This is what I call "the flashback factor", it's got to be good when that happens.
In the comparison with Sota, Arc, and Thiel, you could see the music; no such luck, but this was better than I have ever heard on my rig which includes: Grado Sonata, Rega P3-24, incognito tone arm wire, heavyweight for tonearm, Sheer Audio Platter, Groove Tracer sub platter; those tweaks help a lot.
with the stock new interface, I got the best results going "line in". It's an excellent product for "non audiophiles". After the mods, going "line in" had become a habit. Not until Onhwy61's comments did I go "phono in". The sonics were so improved over going straight into the listening room pre, that there was no need to haul the TT upstairs. While the most dramatic improvement was in dynamic range, there was improvement across the entire spectrum, similar to a big upgrade in cartridge.
I don't believe an audiophile PC interface for analog will ever be available. When you say "analog", PC people give you a blank look, and when you say "PC", analog people don't believe what's possible. But it's all about "whatever floats your boat". My mission is accomplished, enjoy the music.