Audiophile blues...

I've enjoyed the predominantly acoustic, "Come On in the House" by Junior Wells and various slide guitar sidemen. IMO it's the best thing he's done since, "Hoodoo Man Blues". It's available from Telarc on sacd. The audio quality is excellent.

Albert King's "Born Under A Bad Sign" on original Chess vinyl. Maybe not the last word in "audiophile" quality but pretty close.

Two released by Mapleshade Records have excellent SQ
Blue Rider Trio - Preachin' the Blues
Blue Rider Trio - Harp, Steel and Guts

JSP Records SACD release
Deitra Farr - Let it Go

"And since when has 50's technology and Tube equipment been a benchmark for great sound."

Since, well, er......forever?

Shakey

"And since when has 50's technology and Tube equipment been a benchmark for great sound?" Shakey, maybe you ought to tell him that numerous guitar amps of the tubed variety are still in production today, many are considered collector's items for the sound, and many "new" amps have been modelled on the old tube ones. Also, many effects boxes strive to emulate that sound as well. The same goes for tubed audio equipment-some people love old Heathkits and Dynacos, and though far from "perfect" sound, many still love them. Recording companies like EMI still use some tube circuits to record, including certain brands considered to be audiophile labels.