The jazz label, ECM is known for their natural, spacious soundstage reproduction, although, I don't think many of their recordings are done with the "purity" of classical recordings.
Also, ECM was very respected during their vinyl era for sound quality, and they took it very seriously. They pressed their recordings on some of the best quality available, so they were super quiet.
Gallery - David Samuels vibes, David Darling cello, Paul McCandless oboe, Ratso Harris bass, Michael DiPasqua drums.

Azimuth with Ralph Towner - Départ
Kenny Wheeler flugelhorn, Ralph Towner acoustic guitar, John Taylor piano, Norma Winstone voice.

Keith Jarrett piano, Jan Garberak sax, Palle Danielsson bass, Jon Christianson drums - Belonging
ECM made a great transition to CD too, and the maintained their high standards for musicians. Their recent releases have been great sounding, with a new crop of very creative and talented musicians.
Craig Taborn - Daylight Ghosts
Michael Formanek - Small Places
Ralph Allessi trumpet, Andrew Milne piano, Ravi Coltrane sax, Drew Gress bass, Mark Ferber bass - Imaginary Friends
Dominique Pifarély Quartet - Tracé provisoire
And so many more old and new releases.