FWIW

http://www.telarc.com/sacd/pentatonerqr.asp

"The Remastered Quadro Recordings (RQR) series features 1970s Philips
Classics recordings that were originally captured via quadrophonic
technology. All recordings have been remastered for release on hybrid SACD
and are capable of reproducing these spectacular recordings the way they were
originally intended to sound."

r

--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"