Why does your turntable sound the way it does.


Ok, we all seem to agree that turntables sound different, and there are any number of upgrades to a basic turntable that are offered, up to and over $100k. But what is it that causes a turntable to sound the way it does. After all, isnt the basic principal that the table causes the groove undulations to pass by the stylus at a certain speed, thereby creating the sound we hear. If that's true, then only something that affects that point of interaction should have an effect on sound. Forget of course, differences in cartridge, tonearm, wire or preamp. Just think of the turntable itself.
Now, we hear that idler drives are more impactful than belt drives, belt drives are quieter and release more inner detail, direct drives maintain speed and tempo better, aluminum platters sound different than acrylic or glass or MDF. Platter mats can change the sound considerably. different bearing materials and precision in manufacture can change the sound. but why?
Is there a basic sound to be acheived when everything is perfect, and what we are hearing is actually a distortion of that sound based on resonance or time or torque or vibration or whatever. Is there a means of measuring what a cartridge can do in a perfectly set up system where there is no influence on the stylus/vinyl interface and the cartridge is free to follow the groove undulations without exterior influence. Is this perfect environment found in the cutting head, or is it also subject to the same influences as the playback stylus. And if so, how can we ever account for that effect in our playback systems.

So, fellow Audiogoners, what do you think has the greatest effect on vinyl playback as far as only the turntable itself, and what do you think can be done to ammeliorate those effects.
manitunc

Showing 3 responses by atmasphere

I can answer one question here that has to do with the platter and platter pad:

When the needle tracks the groove, the vinyl can talk back to the stylus and thus affect the sound. Just turn down the volume when you are playing an LP and you will see what I mean.

If the vinyl is properly damped, it will sound more neutral and correct, regardless of the drive system. This is because this is a more important feature than the drive. Sure, you can hear differences in the drive, not contesting that.

Anyway, most platter pads don't damp the LP properly! Acrylic is too hard as are metal platters (which work fine if the right platter pad is in place). Rubber and cork are too soft. Warren Gehl of ARC did a lot of reserach in this topic about 20-25 years ago and over a period of years developed what was and still is the best platter pad I've seen. It has the same hardness as the vinyl, which is paramount as if it is any different, the coupling between the two surfaces will not favor all frequencies. At the same time the pad did not depress as the needle tracked the vinyl (there is a microscopic depression around the needle caused by the tracking pressure), yet the pad was designed to damp not only the LP but also the platter.

Sadly, the last of these platter pads was made a good 15 years ago or more, but what those audiophiles that were lucky enough to find one found out is that it almost didn't matter what table you had if it could support this pad (which weighed a few pounds). They all sounded pretty much the same if the pad was in place, which is also to say considerably better than without!

I think someone needs to make a new version of this pad. Warren says he can no longer make it as some of the materials aren't available.

BTW I've played master tapes against the resulting LP many times. I'm not sure I would use the term 'overdamp' but I know what you are talking about. This is actually a coloration caused by the platter pad. Raul is correct- it is actually impossible to in reality overdamp a turntable (or a tube or a transistor...); if you hear something like that what has happened is a coloration has been introduced.

Please note that I did not say its impossible to overdamp a cartridge. With LOMC all that happens is you loose output, but with a moving magnet you will indeed kill the highs if the cartridge is overdamped (meaning the load impedance is too low for it to drive with full bandwidth).
I'm a bit confused. What are you listening for exactly? The sound coming off of the stylus directly into the air?

Yes. If the LP is properly damped it will be quieter. The louder it is, the more problems you are dealing with.

Warren's platter pad was smooth, and was used with a record clamp or similar, as it had a recess to allow for the label. But some LPs, like old 'pancake' Deccas, were flat, so he would use the clamp with an o-ring or the like to dish the LP slightly so it would make contact at the edges.
The plinth is pretty important! One thing is for sure- the coupling between the platter and the cartridge mounting must not have any slop, nor can there be any difference in motion (for example, vibration in the plinth) that otherwise will allow for coloration. For this reason the plinth must have the most supreme rigidity and coupling without resonance between the platter bearing and the base of the arm.

If not there will be a coloration, on account of the arm is moving in a different plane than the platter, which is interpreted by the cartridge as a signal: coloration.