SACD: what it is and what to look for
SACD is the high-resolution disc format that never went mainstream — which is precisely why the good titles are collectable.
What SACD actually is
Super Audio CD stores audio as DSD rather than the PCM used on a standard CD, on a higher-density disc. It was introduced in 1999 as a high-resolution successor, competing with DVD-Audio, and settled into a niche of classical, jazz and audiophile reissues.
Hybrid vs single-layer — the buying decision
Hybrid SACDs carry a normal CD layer as well as the SACD layer, so they play in any CD player. Single-layer SACDs will not play in a standard player at all. Before buying, check the disc face or rear insert for the 'Hybrid' or 'CD layer' wording — this is the single most common mistake new SACD buyers make.
Stereo and multichannel layers
Many SACDs carry both a stereo and a 5.1 multichannel DSD mix. Multichannel titles from the early 2000s are frequently the only surround mix of that album ever released, which is where a lot of the collector value sits.
What to look for
Limited-run audiophile series, out-of-print catalogue titles, and any multichannel mix that was never repeated. Condition matters as with any CD, and the packaging is usually a digipak or gatefold card — grade it accordingly.