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IMHO (and friend's) opinion of acrylic platter

Hello all...

In my quest to tweak my system for a better possible sound...  

I have gone through the latest item for review, inspection and opinion. I picked up an acrylic platter for my Dual 1219 with a Grado Platinum 1.  

Going in, I was highly skeptical and my skepticism was aligned with a myriad of opinions out their on the net. Such as snake oil, yes, no and every variable opinion possible wedged within.  A discussion happens...yet, not quite like when someone asks about "cables".

I set out to give the best subjective platform for the "test".  I called in a friend of 38 years...who is a musician who is gifted with perfect pitch...and not saddled with tinnitus, like me. He is also a luthier as as well...who knows, on a retail, musical and technical level, the best sound possible...and what to listen for...and how.

I set the volume at a reasonable level, placed him in the sweet spot 'tween the speakers...me to his left. I sought  an album we were both very familiar with...one of the most sonically perfect and best produced albums ever... Steely Dan's "Aja".

We started without the platter for "Black Cow".  We sitting respectfully poised, solemn, quiet and with bowed heads carefully and methodically listened and took in as much musical and sonic information our minds and ears could handle.

When done...I asked him to step away...not wanting his to see what I was going to do...I placed the acrylic platter on...and set every up as before.

I started it again.  5 seconds in...we both had an opinion...and we needed to vocalize it... YES...there was a difference and we agreed there was a bit more bass and it was a bit more defined. We listened through the second spinning (with platter) pass at "Black Cow"...and we agreed there WAS indeed a difference.

So...trying to give the situation the best chance to prove us wrong...I sent him away again...removed the platter...ands ran through "Black Cow" a third time.  A scientific  "A-B-A" test.  At he end of the third spin...we were confirmed...  I showed him what the "change" consisted of...and he was very surprised. 

Yes...the platter did administer a subtle, yet still distinct change to the sound.  I didn't want to believe it...but I could not reasonably disagree with what I heard; neither could my friend.

On a technical level...I cannot explain it... Perhaps it was the materials in the platter that affected the relationship between the cartridge, platter, album...with resonance or rumble...wow/flutter?  I dunno.  Or...since the album is sitting 3mm higher, perhaps it has something to do with the VTA setting...making the stylus' relationship with the groove different...or...more like the VTA when the album was originally "cut" on the "master".

I would enjoy responses...

What a hobby!!

Thank you!

Sincerely,

vinylspin
vinylspin
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cleeds
5,642 posts
 
mijostyn
It does not matter what the platter is made of as long as it does not ring.
You’ll find some users here whose experience would definitely contradict that.
Any sonic changes are more likely due to changes in SRA, Azimuth and overhang.
We’ve been through this before. If the pickup arm is properly designed and properly installed, changing VTA will not change azimuth. When working properly, a pickup arm can track even a badly warped LP without azimuth ever changing even a tiny bit.

Of course, VTA/SRA and (depending on the arm) likely VTF will be all over the map. But the azimuth will remain the same. It’s simple geometry.

To be clear, I’m referring here to a conventional pivoted arm. All bets are off if it’s a typical unipivot arm or a linear tracker that uses a funky air bearing - which is one reason why I don’t care for those types of arms. (Plus, I find using a unipivot just creepy, but that’s just a matter of preference.)
mapman's avatar
mapman
21,830 posts
 
There is way too much anger around these days.  I will call a truce and be the first to promise to do  better. Especially here.  It’s really kind of silly grown ups getting so wound up over a bunch of toys. 
mijostyn's avatar
mijostyn
8,159 posts
 
Cleeds, we have been through this before, It does slightly change azimuth. Not as much as SRA and perhaps even overhang(depends on the original position of the arm) but as the arm elevates the stylus starts tilting towards the spindle. 
As for the platter, I said if the original platter does not ring. If it does then a new platter may well make a difference.
We agree whole heartedly on unipivot and linear tracking arms(except the Schroder LT and Reed 5T) Both are fundamentally flawed.
As for the opinions of many? Very few of us think independently, probably less than 0.01% and that would only be with certain subjects. We are subject to influences we may not even be aware of. With something as plastic as human hearing it seems group think predominates and mysticism rules. In reality you can only deal with your own environment
In my own situation if I tapped a platter and I got a ring instead of a thud I would not get a new platter. I would get a mat that dampen the ring. If I felt the platter was a bad design I hope that I would not have bought the thing in the first place but if I did (I have made plenty of mistakes) my response would be to get a new turntable.
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cleeds
5,642 posts
 
mijostyn
(VTA) does slightly change azimuth. Not as much as SRA and perhaps even overhang(depends on the original position of the arm) but as the arm elevates the stylus starts tilting towards the spindle.
Yes, your turntable and arm may do that. I’d consider that an unacceptable defect.

I can assure you that on every turntable/pickup arm combination I’ve ever owned, azimuth has been completely independent of VTA. As you may know, azimuth can be measured, so it’s silly to dispute it.

If your azimuth is changing with VTA, you must suffer a lot of distortion unless you go to great lengths to flatten even slightly warped records. And even then, it’s an unnecessary compromise, imo, but of course it’s fine if you can live with it.
We agree whole heartedly on unipivot and linear tracking arms(except the Schroder LT and Reed 5T)
Have you ever actually heard the Schroder or Reed arms? I haven’t, but these types of "solutions" usually suffer another Achilles heel, such as friction or lack of rigidity.
mglik
887 posts
 
After trying a Puresound Tenuto gunmetal mat and a Ringmat, I have found the best available mat-an acrylic mat by Oracle. It is unlike other acrylic mats being high mass and other factors. The vital importance of a good mat was stressed by Ralph Karsten who recommended it. It costs $200 but is totally worth it. It can be ordered by calling Oracle in Canada. Among many, many improvements, I was stunned by the now near complete silence in the run in groves, in between and runout. The improvements with the Oracle are nothing less than stunning! Highly recommended.
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