Platters

[Snoop65]

Is there really a sonic difference between acrylic, aluminum and any other platter materials that might be out there? If so what is your preference and why?

 

[kach22i]

I hate to hijack your thread before you get a straight answer, but this might get to the core of the issue in an adjacent way.

I've experimented with a lot of different materials under my turntable and pre-amp in an attempt to tune them to a musical resonant frequency sympathetic to my system.

What I have experienced is pretty simple, there is a sound to materials. That is to say the characteristics which we associate with that material will shine through.

I could go though a huge list with many examples, but to cut to the chase, brass is best.

Old thread on the topic:
http://www.martinloganowners.com/forum/showthread.php?9937-What-s-under-your-TT-affects-sound&

Hey Bill, I agree with what you are saying. It follows my own experiments of material under my turntable and speakers.

Wood: can sound warm but grainy

Steel: can sound strong but cold

Glass: can sound clear but with glare

Rubber/Sorbogel: can add lots of bounce to music but spongy sound.

Brass/Bronze: wish a had a semi truck full of it - expensive.

I used both acrylic and aluminum plates to tune and improve the sound of my turntable.

 

[Mosin]

You hear a lot of talk about various aspects of turntables that range from plinths to bearings to oil, etc., etc. However, it is my honest opinion that the platter is the single most important element of any turntable. Which one? Here's the rub; it depends upon the rest of the design. However, a good builder will consider this choice at the outset. It is my opinion that a turntable that has it offered as some sort of upgrade should be viewed with great suspicion. It is the one thing that should be right in the beginning, if nothing else.

 

[rockitman]

my platter uses POM/Delrin material. It is similar in density to vinyl.
http://www2.dupont.com/Plastics/en_US/Products/Delrin/Delrin.html

 

[Mosin]

my platter uses POM/Delrin material. It is similar in density to vinyl.
http://www2.dupont.com/Plastics/en_US/Products/Delrin/Delrin.html

You are right. I really like it, especially a German one called Acetron GP. I like that one because it has a low centerline porosity. It doesn't take in moisture, and is relatively immune to chemicals like alcohol. The other neat thing about acetal in general, beside its friendliness with vinyl, is that it is easy to combine it with a variety of other materials with predictable outcomes. It is extremely durable, too. However, it can be aggravating to work with, depending on what you want to do with it. Still, a winner in my book.

 

[rockitman]

You are right. I really like it, especially a German one called Acetron GP. I like that one because it has a low centerline porosity. It doesn't take in moisture, and is relatively immune to chemicals like alcohol. The other neat thing about acetal in general, beside its friendliness with vinyl, is that it is easy to combine it with a variety of other materials with predictable outcomes. It is extremely durable, too. However, it can be aggravating to work with, depending on what you want to do with it. Still, a winner in my book.

Interesting info Win. Thanks. Perhaps Clearaudio source's that German version ?

 

[Mosin]

Interesting info Win. Thanks. Perhaps Clearaudio source's that German version ?

Sorry, no opinion.

 

[kach22i]

Interesting thread on the topic here:
http://www.diyaudio.com/forums/analogue-source/109940-delrin-hdpe.html

This thread touches on machining issues:
http://www.cnczone.com/forums/diy-cnc_router_table_machines/33215-delrin_hdpe_did_you_use.html

Delrin has a tensile strength of 10 ksi while the HDPE is rated at 4 ksi

.............................

Derlin has slightly lower friction & thermal expansion, and the PE's are more resistant to wear. It goes along with the strength and elastic modulus, but I think Derlin is a little harder than HDPE also.

http://productivity.2mucharticles.c...-dont-know-about-delrin-vs-hdpe-may-cost-you/

What you don’t know about Delrin vs. HDPE may cost you…
Posted on September 8, 2012
Is Delrin and HDPE the same thing?

We frequently get this question asked by our new clients. Is HDPE Sheet the same plastic as Acetal Sheet?
Absolutely not, they are very different materials. Even though the natural color of both of these is a milky white to solid or opaque white, and they do have a rather similar look, they are far from the same. HDPE is normally milky white to almost white depending on the thickness, and Acetal is much more opaque white to slightly milky – once again depending on the chosen thickness .

HDPE and Delrin – A few Differences

The HDPE is considered a softer plastic material, and it is known for its FDA certification and is often placed in numerous food processing applications, such as: the translucent milk jugs, cutting board, colored foggy beverage glasses/cups, and many, many more. Yes, it can be easily machined, because it is a bit softer and lighter, the accuracy it can be machined to are not very tight. It can’t be bonded, so it is therefore a great non-stick surface for a bonding release and adhesives.


The Delrin also is FDA certification, and is often used heavily in the food preparation industry. Delrin material is a better choice for a engineering material and is normally used in bearing and wear strip applications, timing screws, cams, etc. This material is excellent to be machined to tight tolerances, and wears well for long periods with little to no lubrication. Due to the exceptional wear properties, it is also not bondable, thus requiring mechanical fastening or threads to be assembled. It has a very low water absorption, and you will find it in your toilet tank (as the white moving parts) and in the handle mechanism. It is an extremely popular material for machine shops, as it processes much like soft brass.


EVEN THOUGH HDPE AND ACETAL LOOK ABOUT THE SAME, THEY PERFORM QUITE A BIT DIFFERENTLY.
While both HDPE and Acetal are FDA approved, are machinable and can be used to make rigid wear resistant parts, they are definitely different resins and have significant different physical properties. Another important difference is in the weight of these items; HDPE weighs about 35% less than the Acetal material. Please review the data sheets for more information to assist in proper material selection.

Acetal is commonly known as: Delrin, Ensital, Unital, Pomalux, Ultraform and many more.

HDPE is known as: Ultraethylux, Densetec, Polystone G, Fortiflex, Versadur, Hostalen, and many more.

Contact us for more details on the HDPE and Acetal products and other plastic materials, call 866-832-9315

After reading this, it would be interesting to find out is anyone is mechanically fastening Delrin to a brass platter as it might be the best of both worlds. Maybe Teres?

EDIT-1:
http://www.diyaudio.com/forums/analogue-source/143802-what-you-doing-your-new-teres-bearing-3.html

Originally posted by d to the g
Delrin is the best platter material I've ever heard.* Orders of magnitude better than acrylic.

*HAVE heard cork, rubber, carbon fibre, several types of acrylic. Still waiting to hear cocobolo and a few other exotics.

From another thread in this forum I posted this:
Playing with Rubber, Leather, Copper and Carbon
http://www.tnt-audio.com/sorgenti/garrard_mats_e.html

While I liked the three layered mat construction...........

 

[TBone]

You hear a lot of talk about various aspects of turntables that range from plinths to bearings to oil, etc., etc. However, it is my honest opinion that the platter is the single most important element of any turntable. Which one? Here's the rub; it depends upon the rest of the design. However, a good builder will consider this choice at the outset. It is my opinion that a turntable that has it offered as some sort of upgrade should be viewed with great suspicion. It is the one thing that should be right in the beginning, if nothing else.

Well, if the design calls for a compliant mat between platter & LP, the issue of platter material is offset by the choice of mat. If the 'table is designed to direct couple the LP to the platter, then the choice of platter material is much more critical.

However, with direct coupling, you're attaching the LP to the entire turntable structure & it's environment. Therefore, platter material, although important, isn't nearly as critical as the quality of the structure(rigid), bearing, motor and isolation.

My two 'tables have very different platters, one is Delrin and the other Brass.

tb1

 

[Mosin]

...After reading this, it would be interesting to find out is anyone is mechanically fastening Delrin to a brass platter as it might be the best of both worlds...

Well, sort of. My platter is a combination of Delrin, aluminum and brass.

Well, if the design calls for a compliant mat between platter & LP, the issue of platter material is offset by the choice of mat. If the 'table is designed to direct couple the LP to the platter, then the choice of platter material is much more critical.

I admit to a strong bias against compliant mats, so my mind blocked out the possibility of a well designed one when I wrote my post.

However, with direct coupling, you're attaching the LP to the entire turntable structure & it's environment. Therefore, platter material, although important, isn't nearly as critical as the quality of the structure(rigid), bearing, motor and isolation.

This is true. I do believe that initial interface between the vinyl and the turntable is the most important one, however. The structure and environment of the overall turntable can be tuned, but whatever you choose for a platter is something you are going to be stuck with forever. It is like the audio chain in a way. If you start out badly in a non-reversible way, you have already ruined the possibility of a good outcome. I believe that poor choices in platters may be why some exotic turntables exhibit amazing detail, but also display a dry, clinic feel that takes from the experience.

 

[JackD201]

When I used an HRX I had two platters. One was all acrylic and the other a delrin/aluminum sandwich. Is it the choice of material alone? Maybe, maybe not. If one platter was thicker or sat higher than the other thereby creating differences in VTA, that too might have caused at least some difference. Whatever the case may be, they did sound demonstrably different. I preffered the latter if anyone is curious.

 

[Mosin]

Jack,

Let me make a guess. The acrylic one sounded ever so slightly veiled in comparison, and the delrin/aluminum sandwich sounded considerably more detailed, yet it retained a musical presence without quite as much warmth, correct?

 

[kach22i]

My platter is a combination of Delrin, aluminum and brass.

What turntable is that platter on?

I'd like to find out more.

EDIT-1:
Is it the Win?
http://www.oswaldsmillaudio.com/Products/turntables.html

EDIT-2:

When I used an HRX I had two platters. One was all acrylic and the other a delrin/aluminum sandwich..... I preffered the latter

The big VPI, nice machinery.

 

[paskinn]

Interestingly enough, SME have always been insistent that the special type of covering they use on their platters is vital.They always buy the rubbery/plasticky compound from the same supplier, and when he stopped offering olive green as an option SME started using the black isodamp. We'l never know what difference it makes, because it can't be removed; and if you spoil it, it is very expensive to get replaced (well, I think you have to buy a new platter.)BTW, the black and green isodamp are the same, with different pigmentation.
We haven't mentioned one other issue....clamp or no-clamp platter?

 

[GaryProtein]

Are you sure the black doesn't give a darker sound?

 

[Snoop65]

Thanks to all that have responded. This has been a good read. I have heard of manufacturers offering two platters either as a upgrade or to suit the sonic taste of the buyer.

 

[Snoop65]

Interestingly enough, SME have always been insistent that the special type of covering they use on their platters is vital.They always buy the rubbery/plasticky compound from the same supplier, and when he stopped offering olive green as an option SME started using the black isodamp. We'l never know what difference it makes, because it can't be removed; and if you spoil it, it is very expensive to get replaced (well, I think you have to buy a new platter.)BTW, the black and green isodamp are the same, with different pigmentation.
We haven't mentioned one other issue....clamp or no-clamp platter?

Clamp or no clamp is a good question. When I asked my audio dealer about a clamp he didn't recommend it, at least not for my table. He said I could explore it later.

 

[paskinn]

Are you sure the black doesn't give a darker sound?

Now that you mention it, it does give a darker smoother sound; and the olive green gives a kind of 'olive green' sound.

 

[kach22i]

Now that you mention it, it does give a darker smoother sound; and the olive green gives a kind of 'olive green' sound.

Is the olive green drab?

http://blogs.motortrend.com/4x4-hea...oing-it-right-at-moab-1825.html#axzz2Kzwx3jbL

 

[Snoop65]

is the olive green drab?

http://blogs.motortrend.com/4x4-hea...oing-it-right-at-moab-1825.html#axzz2kzwx3jbl

lol!!!:d