Short for "Super Audio CD", this new audio format was released by Sony in 2000. It is a rival to the even newer DVD Audio format. SACD now officially supports multichannel sound. Super Audio CDs are physically the same discs as DVDs, but the 4+ GB of storage space is used entirely to store digital audio, in uncompressed format. Unlike regular CDs and DVD Audio discs, which use PCM encoding, the SACD format uses DSD, a much simpler technique for converting sound into digital data. DSD requires less intermediate steps (and therefore audio and electronic components) for converting the digital data back to analog format for playback through speakers and such. SACD's DSD format stores sound samples at 2.8Mhz 1-bit depth. SACD is, of course, a high-end format for audiophiles only! Players (from Sony or Marantz) currently cost between $US 750 and $US 5000. One nice thing about this new audio format though, is that an SACD disc can be backwards compatible with your existing CD player. That's right, your current CD player's laser will focus on a second layer of data that can be recorded in good old 44 Khz, 16-bit format. That way, your perfect sound forever CD player can still play one of these "hybrid" SACD discs and therefore music stores won't have to carry dual inventories. Unfortunately, until today, Mid-2002, few SACDs are can be found in music stores, and even fewer are hybrid discs.