ELP laser turntable - any comments?

I presume that the laser circuitry derives a digital signal from its optical inspection of the groove, which makes for the oportunity to do RIAA equalization and some pop and click elimination in the digital domain. But if the signal is digital, why bother with a mechanical recording media (vinyl) in the first place?

By the way, digital data can be recorded on vinyl, and played back with a normal phono pickup. At one time, on an experimental basis, stock market information was distributed this way, because a LP, once cut, can be rapidly reproduced by stamping out copies. At the time mag tape was the only other alternative, and mag tape takes time to copy because the tape must be drawn by the head. Digital data could use error correction encoding so that surface noise would not be a problem, but this digital approach would not work for music because the sample rate would be much too low.

Well, I read the review, and am surprised to find that the device claims to be completely analog. I wonder if this includes the focusing servos.

I bet you could do a better technical job with a digital approach (certainly the noise problem could be solved) but of course the "analog" label is probably very important in marketing the thing.

A dynamic phono pickup, MM or MC, puts out a voltage that is proportional to the RATE of stylus movement. A piezioelectric phono pickup (and there were some that were not cheap junk) puts out a voltage that is proportional to the DISPLACEMENT (distance of movement) of the stylus. And yet, both can play the same LP groove, and sound more or less the same. This has always puzzled me.

Now, I wonder what kind of signal the laser pickup produces...rate or displacement, or something else. Clearly there is room for a distinctly different sound from the same groove.

Useridchallenged...The Halcyonics table is completely self-contained and easy to use. Just adjust (knob) for the load weight (as indicated by a LED). At work it performed flawlessly in a critical optical task. (Eliminated ripples in a pool of Mercury).

Tbg...I never used it for audio, but the task of eliminating ripples in a dish of Mercury is a real vibration isolation challenge, and the Halcyonics table came through with flying colors. At the time I thought that it would make a great base for a turntable. Now I understand that someone is marketing it to audiophiles.

Are you suggesting an A/B test against the Minus K ? ! ! :-)

Useridchallenged...I think that Halcyonics has various models, some of which will support more weight. The 220 pound model should be sufficient for 99.9 percent of turntables.

Thanks for the info on the patent. I will look it over.

OK Sam! A good posting.

I guess it's time for me to "disclaim" any connection with Halcyonics. I have mentioned this product only because I had such good experience with it in a non-audio job-related situation.

Tbg...If your TT moves 1/2 inch vertically, and 3/4 inch horizontally, I submit that you have best evacuate the house, especially if you live in California! As to specs...40 dB and 50dB are not significantly different in terms of real world effectiveness, and may be dependent on exactly how the number is measured. Same goes for 0.5 Hz vs 0.6 Hz. A side-by-side evaluation would be interesting, although I bet that either one would take care of the typical home floor vibration. In my experience acoustic feedback to the vinyl is the predominant problem after even minimal attention to floor vibration.

It occurs to me that a conventional phono pickup is basically a cam follower...a mechanical device to trace the shape of a template (the recorded groove). We think of it as a very small mechanical device but it is actually very large in context of the technology of "nanomechanical" machines, a field that has seen amazing progress in recent years. If someone (with a lot of money) wanted to make a giant leap forward in vinyl playback I think that a nanomechanical phono pickup would make more sense than this optical approach.

Nanomechanical machines are fabricated like electronic integrated circuits, and usually include, on the same chip, the associated electronic circuits. Tracking force would be so low that you might need an optical servo arm to track the groove.

A project to develop such a pickup would be attractive only to a multimillionare audiophile with technical leanings and not enough to do. Anyone out there?

Tbg...That's what I would expect based on my experience with the Halcyonics. Enjoy!