Pages 16-18 of the new December 2019 issue of Stereophile magazine feature a discussion of CD-4 by Stereophile editor Jim Austin. In the brief piece he discusses Richard Brice’s efforts at developing useful CD-4 decoding software for a company called Pspatial Audio. As I have no direct or indirect experience with quad vinyl, 8 track or R2R, I would be interested to read the thoughts and assessments of some of the folks here who have extensive experience in working with CD-4. It might also be worthwhile for anyone either having a helpful response to Mr. Austin’s piece or, perhaps, a bit of useful information to share with Stereophile’s readers to, then, consider writing a letter to the editor.