OMA polycrystalline graphite mat - why does it work?

Cedar

Member
May 21, 2020
8
0
6
Sacramento CA
I acquired an Oswald Mills Audio (OMA) polycrystalline graphite platter mat. To my ear, it improved the music quality enough that I judge the mat to be worth more than the cost ($465 delivered). My turntable is a Technics SP10 MK2.

Why does it work so well? I suggest one possible explanation below. Maybe someone can help me to understand better what is going on.

There is almost no information about this mat available. OMA states that the platter mat material is “an extremely high grade polycrystalline graphite." What is polycrystalline graphite? I found that more than one form of it exists, including graphene. One research paper compared wave propagation in two configurations of graphene sheets: single crystal and polycrystalline. I don’t think the OMA mat is made from graphene material. However, it may be that the OMA material shares the wave propagation characteristics of polycrystalline graphene.

Graphene is a two dimensional form of graphite. As described at www.nanografi.com:

Graphene is a material composed of pure carbon, similar to graphite but with characteristics that make it extraordinarily light and strong. A sheet of one square meter of graphene weighs 0.77 milligrams. Its strength is 200 times greater than that of steel and its density is similar to that of carbon fiber. All these make it resist high bending forces without breaking. It is one of the most conductive materials for electricity and heat, which makes it the perfect material for electronics and many other industries.

Oscillating wave propagation in polycrystalline graphene is reported to be isotrophic and highly damped. A material that propagates oscillating waves identically in all directions is said to be isotrophic. So, oscillating waves propagated through polycrystalline graphene are highly and equally damped in all directions.

These polycrystalline graphene properties, if shared, may mean that the OMA mat absorbs oscillating waves received from the stylus and from the platter but effectively dampens their reflection. This result would explain the beneficial effects of the OMA mat that I have heard.

Cited research paper:

https://pubs.rsc.org/en/content/articlehtml/2017/ra/c7ra03744a
 

djsina2

Well-Known Member
May 31, 2019
792
579
168
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I acquired an Oswald Mills Audio (OMA) polycrystalline graphite platter mat. To my ear, it improved the music quality enough that I judge the mat to be worth more than the cost ($465 delivered). My turntable is a Technics SP10 MK2.

Why does it work so well? I suggest one possible explanation below. Maybe someone can help me to understand better what is going on.

There is almost no information about this mat available. OMA states that the platter mat material is “an extremely high grade polycrystalline graphite." What is polycrystalline graphite? I found that more than one form of it exists, including graphene. One research paper compared wave propagation in two configurations of graphene sheets: single crystal and polycrystalline. I don’t think the OMA mat is made from graphene material. However, it may be that the OMA material shares the wave propagation characteristics of polycrystalline graphene.

Graphene is a two dimensional form of graphite. As described at www.nanografi.com:

Graphene is a material composed of pure carbon, similar to graphite but with characteristics that make it extraordinarily light and strong. A sheet of one square meter of graphene weighs 0.77 milligrams. Its strength is 200 times greater than that of steel and its density is similar to that of carbon fiber. All these make it resist high bending forces without breaking. It is one of the most conductive materials for electricity and heat, which makes it the perfect material for electronics and many other industries.

Oscillating wave propagation in polycrystalline graphene is reported to be isotrophic and highly damped. A material that propagates oscillating waves identically in all directions is said to be isotrophic. So, oscillating waves propagated through polycrystalline graphene are highly and equally damped in all directions.

These polycrystalline graphene properties, if shared, may mean that the OMA mat absorbs oscillating waves received from the stylus and from the platter but effectively dampens their reflection. This result would explain the beneficial effects of the OMA mat that I have heard.

Cited research paper:

https://pubs.rsc.org/en/content/articlehtml/2017/ra/c7ra03744a
I have the Audio Tekne “mat” made from their own proprietary carbon material and I too thought it was a big improvement. This is what they say about it…

“Since the fine carbon particles in this sheet are spherical, and thus, capable of diffusing and absorbing vibration waves, this sheet is capable of absorbing any vibration between the surfaces of a disk and a turntable smoothly without returning irregular vibration to the disk. Therefore, through all the spectrum, music sound recorded in the disk will be reproduced in an ideally natural manner (in terms of transparency, sound source localization and definition).
Since energy loss is smaller than that of ordinary turntable mat, the reproduced music will be free from vagueness, distortion and dullness, bringing to you 20 to 30% higher auditory power and the feel of larger scale.”
 

Cedar

Member
May 21, 2020
8
0
6
Sacramento CA
I have the Audio Tekne “mat” made from their own proprietary carbon material and I too thought it was a big improvement. This is what they say about it…

“Since the fine carbon particles in this sheet are spherical, and thus, capable of diffusing and absorbing vibration waves, this sheet is capable of absorbing any vibration between the surfaces of a disk and a turntable smoothly without returning irregular vibration to the disk. Therefore, through all the spectrum, music sound recorded in the disk will be reproduced in an ideally natural manner (in terms of transparency, sound source localization and definition).
Since energy loss is smaller than that of ordinary turntable mat, the reproduced music will be free from vagueness, distortion and dullness, bringing to you 20 to 30% higher auditory power and the feel of larger scale.”
dsjina2,
Thanks for your contribution. It looks like both information sources (Audio Tekne and the research paper) comment about wave propagation. However, the polycrystalline graphite shape is something different than a sphere, I think. But maybe Audio Teaneck refers to a different scale of resolution?
 

Solypsa

Well-Known Member
Jun 7, 2017
1,137
757
220
Seattle
www.solypsa.com
@Cedar thanks for the comments on the mat. I'm always happy to gather potential data points esp. for the sp10mk2. Speaking of which how do you feel about the Krebs mod on yours?
 

Cedar

Member
May 21, 2020
8
0
6
Sacramento CA
@Cedar thanks for the comments on the mat. I'm always happy to gather potential data points esp. for the sp10mk2. Speaking of which how do you feel about the Krebs mod on yours?
Solypsa,
You've taken me by surprise in asking about the Krebs upgrade. I wonder how you learned my SP10 was upgraded in that way by Bill Thalmann at Music Technology Inc. The Krebs upgrade was combined with a re-cap of the turntable assembly, so I really can't separate my experience of the two upgrades. Bill did a fine job of improving the speed accuracy and consistency of the unit. He proved himself to be a good service provider. It has been reliable and responsive since that work, about two years ago. I expect to continue to be so well into the future.
 

Solypsa

Well-Known Member
Jun 7, 2017
1,137
757
220
Seattle
www.solypsa.com
Sorry to surprise you ;)

Since your opening post mentioned your Sp10mk2 I just looked at your 'about' profile where you list the turntable as Krebs mod'd thats all...
 
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Cedar

Member
May 21, 2020
8
0
6
Sacramento CA
I have the Audio Tekne “mat” made from their own proprietary carbon material and I too thought it was a big improvement. This is what they say about it…

“Since the fine carbon particles in this sheet are spherical, and thus, capable of diffusing and absorbing vibration waves, this sheet is capable of absorbing any vibration between the surfaces of a disk and a turntable smoothly without returning irregular vibration to the disk. Therefore, through all the spectrum, music sound recorded in the disk will be reproduced in an ideally natural manner (in terms of transparency, sound source localization and definition).
Since energy loss is smaller than that of ordinary turntable mat, the reproduced music will be free from vagueness, distortion and dullness, bringing to you 20 to 30% higher auditory power and the feel of larger scale.”
djsina2,
Your post led me to the Audio Tekne webpage. They specify their platter as
Thickness : 10mm Weight : 1.0Kg
The OMA mat is specified as 6 mm thick and 1.5 lbs. So there are considerable physical differences. But I do think the Audio Tekne description of the sonic improvements would apply equally to the OMA mat.
 

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