All that is gold doesn’t necessarily glitter. Three labels (MobileFidelity Sound Lab, Sony’s MasterSound, and DCC Compact Classics) arenow marketing 24- karat-gold-plated CDs in limited editions that sellfor $30-roughly twice the price of regular discs. The advantage issupposed to be sound quality: While garden-variety CDs are made fromtapes created specifically for vinyl, gold discs are made directlyfrom the original master tapes in batches of 30,000 to 40,000 and arereengineered for the best possible sound.But is their sound really that golden? Although some audiophilesswear by them, says Richard Lehnert, music editor of Stereophilemagazine, ”to the average person I would say it’s not going to makeany difference.” We gave Lehnert a test, asking him to compare MobileFidelity’s gold-CD version of the Allman Brothers’ At Fillmore Eastwith the regular CD and vinyl LP versions. A true audiophile, hefound the gold disc ”considerably superior” to the regular CD-but theLP sounded better than both of them. So much for progress.