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
Hello...

Thank you all for your varied and detailed responses to my issues with my old Dual 1219.  It would seem that with my desires to move up the food chain sound-wise, I have exceeded the old turntable's abilities.  The 50 year old technology just isn't up to the challenge of  meeting and fitfully answering all of the 21st century's type of adjustments needed.  The good news is that because of the powerful and thorough resurgence of vinyl over the last decade, the modern turntable has been technologically brought up to speed.

Thank you lewm for the kind, respectful and gentle way of suggesting that the old Dual 1219 has already lived its best days.  Back in the day it was indeed state-of-the-art...but now...sadly if I want to sally forth...I simply need to carefully box it up and put her in the garage.

I have been looking at the Flaunce RT 85...but, I do not want the cartridge it is equipped with out of the box...the Ortofon Blue.  I want to move into the AT VM 760 SLC.  I might go with an Audio Technica turntable...the  "Audio-Technica AT-LPW40".  I dunno...maybe the  "Consumer AT-LP140XP".  I new thing to ponder...

I also know that a short future is in store for my '83 Yamaha seperates...M-7- and C-70. they're tired too. but, that  particular swap is another day...

Like I have said...what a hobby!

Again...thanks to all for your words and attention to detail...greatly appreciated.

as always...thanks for reading...

vinylspin
It would seem to me that to compensate for the fact that the album is now 3mm higher, I would consider utilizing the multi-record lever on the back that would literally raise the tone arm.

The way I would approach this to set your VTA de novo.  As for the platter, yes the materials do make a difference.  Everything has its own resonance.  It can also make a difference if it is heavier (or lighter).  By and large a heavier platter will improve inertia - the downsides being more weight on the bearing. And depending on the motor it may put some strain on that.
Another thing you can try (I have done this with many Technics platters) is to strip away the rubber on your metal platter.  Before you start hit your platter with a spoon and try to remember the sound (or record it).  Also weigh your platter.  This stripping is a difficult job.  But if you stick with it you will have bare metal.  Again for fun hit it again with a spoon.  It will ring even more.  This is why metal platters have to have damping.  Then with your platter upside down on a perfectly flat surface you pour in some epoxy - Gflex for choice.  Wait for this to harden.  What you will have left is the original platter with vastly better damping.  

Metal platters have to have the ringing addressed.  Replacement, Good Damping, or an Oyaide Butyl mat.  

Vinyl spin, can you remove the OEM rubber mat and just plop the acrylic mat on the bare metal surface of the platter? If so , try that.

With all respect, the 1019 is a fine vintage piece, but it was not meant for this sort of tweaking. It is simply not adjustable enough in its single play mode. If putting the acrylic mat directly on the metal platter does not work, I advise you to go back to the stock rubber mat and enjoy the turntable as is.
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.
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.
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.
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
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.)
Another possible explanation...the 1219’s rubber insert mat is dished, and supports the record at the outer circumference and at the spindle, leaving the recorded surface unsupported. With the added acrylic mat, that deficiency is eliminated. Will more defined bass response result? I’d think so. 
Hear here mapman.
It will be much better if millercarbon threatens not to write posts any more than not to read them.
Can we hope?
Mr. br3098 has left us with a piece of artistry he may not even recognize the import of, but his simple missive has caused the classroom bully to run home butt hurt. I do believe he has cracked the code, and stand gobsmacked in awe of his achievement. 
..just my personal experience.   When I got rid of the acrylic platter on my VPI and put on the Classic, metal platter.....it was as though I removed a blanket from my system.
MC maybe just leave already rather than wishing for everyone else to get the boot. You will be much happier not having to deal with all us dummies. I’m sure you will find new people to put on your hate list.

Over and out. 
" Sorry, but I'm developing quite a low tolerance for arrogant ignorant wanna-be posers these days. Hope your ego got a nice little shot out of it"

Ha ha ha ha... this made me laugh out loud. He must not have any mirrors in his house! Ha ha ha ... still rolling... Hoo  boy, that was a good one!
I like my New SR platter mat. It replaces a herbies grungbuster. 
@millercarbon is right, and whoever that dude is that tried to rip him is a tool 
"...its the last comment of yours I'll be reading."
Soon, millercarbon will have nobody left to be mad at.
Hey uberwaltz, you never apologized for insinuating that I was degrading everyone's system when I was rather obviously not.
Don't hold your breath.......
Thank you all for your the kind input.

The new acrylic platter was placed on a "stock" Dual 1219 platter; the metal kind with a rubber inlay. 

It would seem to me that to compensate for the fact that the album is now 3mm higher, I would consider utilizing the multi-record lever on the back that would literally raise the tone arm. To me, that would seem to be a type of compensation. The thickness of the acrylic platter is 3mm and would logically seem as if another record was placed on the turntable...therefore requiring the multi-record lever to be used.    But, a little research uncovered that apparently there are "shims" that Dual used to furnish that...I am guessing... would be placed in the cartridge head-shell to lower the cartridge.

Hmmmm.

So...because of the 3mm rise of the  album...I just did another "check".  Again playing "Black Cow"...I utilized the multi-record feature... starting with the regular single record setting...I went back and forth a few times.  The change wasn't as obvious...but...there seemed to be a bit more "punch" in the multi-record setting.  The "new" broader and defined bass I discovered yesterday was still intact.   Though, regretfully, I did not have the benefit of my musician friend's ear...I made this determination on my own.  I've picked one over the other...it would be the multi-record setting because of the subtle added "punch".   

Aside from shims...for the head-shell...I am also thinking that since my turntable is actually from technology that is 50 years old...I might have to just accept that or invest in a higher end turntable.  but, funds currently prohibit that option.  I'll have to keep "tweaking".

Again...what a hobby. :)

Thanks for reading.
vinylspin
Is it a mat?
Is it a platter?
Is it a dumb question?
Is it an insult?
Delicious 
Hey uberwaltz, you never apologized for insinuating that I was degrading everyone's system when I was rather obviously not. 

It does not matter what the platter is made of as long as it does not ring. 
Any sonic changes are more likely due to changes in SRA, Azimuth and overhang. 
Just to clarify you added a 3mm acrylic turntable mat and did not actually replace the entire platter is how I read the description.  That would be equivalent of lowering the tonearm pivot 3mm and could easily account for the changes you enjoyed.  If there is any VTA/SRA adjustment on your tonearm it would be enlightening to raise the tonearm pivot the same 3mm that is added to the platter (tonearm in same degree of level in both scenarios) and you might have additional insight as to the benefit of the acrylic mat.  So much to try and enjoy in this hobby.  
Maybe you have spent your life listening to mass loaded, overdamped tonearms and spherical stylii? I'm not trying to be insulting. I'm just wondering what could cause you to make such an outrageously silly statement.

Yes, you are. Deliberately insulting. And no, you're not wondering, not at all. Because I stated very clearly exactly what my opinion is based on. A demo conducted in person and before a large group of audiophiles.

Not my fault your experience has been with platters not very far apart in performance. It is however your fault that you choose to ignore everything I said in order to throw your shamelessly gratuitous insult my way.

Sorry, but I'm developing quite a low tolerance for arrogant ignorant wanna-be posers these days. Hope your ego got a nice little shot out of it, its the last comment of yours I'll be reading. Hope it was worth it to you. Bye!
The difference between platters is much greater than even that much VTA.
@millercarbon  What, seriously?

I have mounted hundreds (if not thousand) of cartridges in my otherwise wasted lifetime and I always use the "ear" method for making final adjustments to VTA.  And I have experimented with several different platter materials on various turntables, as a rebuilder and later as a dealer. There is no doubt that changing the platter material makes a difference in sound. Some materials sound better on certain turntables than others, but you can always hear the difference.

But I have never heard a platter change that is as noticeable and significant as properly vs. improperly adjusted VTA. It's a night and day difference with many cartridges and stylus shapes.

Maybe you have spent your life listening to mass loaded, overdamped tonearms and spherical stylii? I'm not trying to be insulting. I'm just wondering what could cause you to make such an outrageously silly statement.

Yes you should have corrected for VTA. Not that it would change much. The difference between platters is much greater than even that much VTA.

The improvement is of course due largely to vibration control, and also mass. If the acrylic platter is more massive that alone will improve bass drive and make the music more compelling and dynamic.

I know this from having compared four different platters side by side. My table is based on Chris Brady's Teres Audio design. Chris offered four different platters of different materials but otherwise dimensionally identical. https://systems.audiogon.com/systems/8367#&gid=1&pid=10 Mine is acrylic lead shot filled. Another acrylic platter identical but without lead shot is clearly not as good. They made one out of cocobolo also lead shot loaded but stabilized wood, much more expensive and clearly better. These could be swapped with no change in VTA. Everyone who heard the demo heard the obvious differences.



vinylspin
... since the album is sitting 3mm higher, perhaps it has something to do with the VTA setting ...
If you made no adjustments af
Changing to a thicker platter means you've also changed VTA, SRA, and overhang. So what you heard could be the result of those as well as the different platter itself.