Laser vs needle turntable

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Laser vs needle turable

Hi there guys,

I was curious to find out whats the difference between the laser and needle turntables? Does anyone own the laser player?whats the difference in sound quality? I was inclined in buying a turtable and came across this laser TT. I thought you experts would know better than me as I am new to this vinyl but certainly immpressed with the quality of sound with the TT's.

here's the link www.high-endaudio.com/RC-ELP.html

Thanx.

Tony
 

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The laser turntable should be the best but I've read that they suffer from record surface noise. The laser cannot push dust out of the way like a physical stylus can.

I'd prefer a laser pickup as there would be zero record wear and there would be no penalty in record life if you played the same track more than once times in a row in the same day.
 
This topic has been discussed in numerous posts on the Audio Asylum.

Here's my contribution.

http://www.audioasylum.com/scripts/t.pl?f=vinyl&m=332154

The key point is that vinyl (also lacquer) is a deformable material, and LPs have been mastered to sound "right" when the groove has been deformed by the localized pressure of a stylus. Remove the localized pressure, and you are listening to something other than the playback conditions that the cutting engineer mastered the LP for.

Not necessarily bad, but certainly different.

hth, jonathan carr
 
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Joined 2003
jcarr said:
The key point is that vinyl (also lacquer) is a deformable material, and LPs have been mastered to sound "right" when the groove has been deformed by the localized pressure of a stylus. Remove the localized pressure, and you are listening to something other than the playback conditions that the cutting engineer mastered the LP for.

An interesting thought, but I think we can probably assume that record companies do not supply their cutting engineers with top-of-the-range
cartridges at >$2000 a pop. Since one of the major differences with more expensive cartridges tends to be stylus profile, I would expect that to affect springback of the vinyl, so we're in the position of "what is a typical cartridge?" Comments?

I must make it quite clear that I have never even seen (in the flesh) or heard a Finial turntable, but there was an interesting paper in the JAES a while ago about using a scanning microscope to recover groove information. Obviously, it wasn't a practical method for day-to-day playing, but useful for archives.
 
The deformation Jonathan talks about is quite real, but to the extent that it does not mimic the motion of the cutting head, it's a distortion. Presumably, any springback from the cutting process is not at all a mirror image of the deformation caused by a playback stylus.

Perhaps this is why, despite tracing issues, many prefer the sound of a spherical stylus, which exerts the least pressure on the groove walls (for a given tracking weight, not a minor qualification!).
 
Sy: My take on the situation is that what the cutting head puts into the LP groove is a signal that has been pre-distorted by the cutting engineer, with the compensating distortion being the localized pressure of the stylus. Groove deformation (as seen from the stylus) is highest with a spherical stylus, since the tracking force is concentrated in a much smaller contact patch than you find with line-contact styli.

EC8010: Back in the heydays of vinyl, you could find line-contact styli on some pretty affordable cartridges. In fact, very few super-expensive cartridges existed at that time, since most were designed for volume sales and efficient mass-production techniques.

The Denon 103 line included at least three line-contact models (103D, 103S, 103M), and none of these models retailed for more than 30,000 JPY. Even today, affordable cartridges like the Audio-Technica OC9 and Shure V15MR sport microridge styli, which IMO is one of the world's top three off-the-shelf stylus profiles.

best, jonathan carr
 
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Joined 2003
I've just had a rummage in my older books and found a mention of pre-distortion in a section concerning translation loss:

"Having said that, however, note must be made of the fact that some (very few) discs are recorded in such a manner that distortion is purposely introduced. The distortion is of such a nature that on replay it tends to cancel tracing distortion, but this can only happen when the distortion is of a level produced by a particular replay stylus radius, which with the Dynagroove records is 0.0007". The distortion is applied during recording antiphase with that produced on replay."

("Pickups and loudspeakers" John Earl. (1971) Fountain Press. P110)

Unfortunately, the book goes on to say:

"Thus on replay, with the correct stylus tip, one cancels the other. It is certainly a brilliant idea, but not very practical as things stand at the moment. Predistorted discs played with an elliptical or biradial tip of 0.0007" by 0.0003" appear not to "sound" much more distorted than those recorded in the more conventional way."

I'm not quite sure what we can glean from that last sentence as the state of vinyl replay in the early 70s was not as good as it can be now.

"Hi-Fi in the Home" 4th Ed. (1973) by John Crabbe also mentions pre-distortion whilst covering tracing distortion and refers to RCA-Victors's Dynagroove records but then says that, "Other record producers are experimenting with such ideas, and it is to be hoped that a standard process will be evolved giving minimum distortion for all types of pickup using an agreed stylus tip size."

However, cancelling distortion in this way is similar to distortion cancellation in succeeding stages of valve amplifiers. It's theoretically possible, but although you may be able to reduce the level of the 2nd harmonic, the level of the higher harmonics tends to increase. Possibly significantly, the "Handbook for Sound Engineers" (which has a very good section on LP) doesn't mention pre-distortion, so perhaps it was an experiment that never took off?
 
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