This is a post from the museum section of my AV room.\n\nThe dbx encoded LP is seldom talked about, however it was an overlooked technology that equals the CD and in some aspects surpasses it.\n\nIn 1971, the dbx system appeared in competition with Dolby. In my view it was superior. It was a professional format to increase the dynamic range of master studio recordings and lower the noise floor. I was an early adopter, and was making professional recordings at that time, 1973 actually.\n\nLater the domestic dbx-2 code encode system was introduced as a domestic format. The original professional format became dbx-1.\n\nIn 1972 a version of dbx-II was introduced to encode LPs. To play the LPs, the decoder had to be placed in a tape loop.\n\nNo significant number of encoded discs appeared until 1977\/1978 time frame. As digital techniques appeared dbx encoded discs faded rapidly after 1982, and was gone entirely by 1984. No significant number were produced after 1982. So it had a short life in the sun.\n\nHowever as a medium it delivered. The dynamic range achievable is 120 db. This bests CD by 30 db, and is comparable to SACD and high bit rate PCM and Bitstream.\n\nThe surface noise is totally inaudible. The distortion is markedly reduced, and not audible on the inside grooves, as the disc modulation can be substantially reduced.\n\nI have a few dbx II discs and a few open reel encoded 7.5 ips encoded commercial reel to reel tapes.\n\nHere is a picture of a dbx-II encoded LP.\n\n\n\nHere is a picture of my Quad 44 preamp, with the disc button activated and the Tape I monitor loop red light glowing. The Quad 44 has two tape monitor loops, so that you can dub from two three head tape machines in both directions, and off tape monitor in both those directions. This is just another example of how Peter Walker's genius always got it right, and makes his units so valuable today. Since he was such a stickler for product reliability, his gear can still be enjoyed and put into service by many. No wonder his gear continues to rise in value even against inflation.\n\n\n\nHear is a picture of my dbx-II NX-40 which can decode both dbx-II encoded tapes and LPs.\n\n\n\nThis is now a little known by-way in the history of the LP. It was capable of truly superb reproduction.