dicas@decvax.UUCP (12/24/83)
Finally! I saw the laser record playing system about two years ago in a prototype form at the factory on Rt. 128, and I thought they had given up or something. While I haven't heard the production version, the prototype was really impressive. They had, at least in the prototype (and I can't imagine them removing it) some circuitry that could recognize things like dust (since the dust doesn't occupy the whole record groove, just part of it) and ignore it. I played my Sheffield Labs Mayorga on it, and I was absolutely blown away by the lack of background noise, it sounded like I was wearing the vibraphone! I wish I knew how much it cost, I think it's a MUCH better idea than these silly digital players. (After all, I can't see how one can turn a staircase back into a sine wave. I was always told that it's theoretically impossible.) Does anyone out there in netland have a list of dealers, a price, or any info about where I can see the production version? <I was there, yes, but Rt. 128 is a BIG place...> Sincerely, Harry Dicaster decvax!dicas
pmr@drufl.UUCP (Rastocny) (12/28/83)
Who was the manufacturer? I'd be very interrested in hearing this gizmo. Please post information you get to the net. About your digital comments, remember that CD players AND this gadget probably both use similar digital techniques. From your description, a zero-crossing detector is most likely used to scan the groove undulations in playback. This circuit produces a square wave analog of the record "bumps." Each time the laser's companion photodetector "sees" a reflection it produces an output level change. (A digital signal from an analog source.) About the same low-pass filtering problems would apply to this gadget as they do to CD players. Phil Rastocny ..!drufl!pmr