A $300-$400 turntable tweak

J Carr:
The A.R.T. graphite mat that I have bonded to the TT-1000...

Jonathan, have you experimented with the A.R.T graphite record clamp? It has awkward dimensions making it impossible for certain cartridges to clear the final few grooves of an LP. I have a feeling though that you are not using Koetsus :-).

The above problem not withstanding, the combination of the A.R.T graphite mat and clamp is very rewarding on my Clearaudio Master Reference with magnetic bearing.

On a related note, can you suggest a place that I can have that A.R.T graphite clamp 'shaved' so that it is compatible with all cartridges?

A long thread. Took me time to read it. I just want to make a note that I have a few outer rings. I have the Kenwood outer ring which weighs about 1.3 kg and a RSR outer ring which if I remember right weighs 330 gms. What I have discovered is that is that an outer ring can be and mostly is benificial sonically (mind you I barely use it due to the PITA it presents)but that is in relation to the RSR ring. The Kenwood more often than not sucks the life out of LPs. That is why I purchased the RSR. I do use the Kenwood on severely dished LPs as the RSR is too light to flatten them. For a record clamp I use the Harmonix, my mat is a Mystic Mat and the TT is a Black Night for reference. Is is suspended very effectively.

What the RSR does is give you a touch more detail and dynamic agility.

I always wanted to design my own outer ring that would have weights that can be inserted along the perimeter to establish what weight is best sonically.

As for record clamps, I find a very slight sonic difference between using the Harmonix and not. But I do use it all the time. Otherwise the LP is not as well coupled to the platter and on startup the LP will spin on the mat.

On to mats, the Mystic Mat sounds very similar to the copper platter direct. What it does do is make the sound a hair more natural. Just a hair and blind testing if you adjust VTA I doubt most would hear it. Almost identical. I tried a Boston Audio mat and found it truncated the leading edge of instruments and made them sound flat. That is in my system. For others it might be different. As a result I am not a fan of graphite mats / platters.

As such we honestly need to look at the entire system to determine what is beneficial or not. I could see a turntable being designed where an outer ring would be beneficial provided the platter can transmit the energy stored between the LP and interface away from the stylus.

Halcro, thanks for starting this thread. Very ear-opening. It never occurred to me to try my VPI HRX without the periphery clamp as it came with the turntable. Based on one weekend of listening the table seems to sound better without it -- slightly bigger sound stage, more open and lively. This was with the Airtight PC-1 cart and 2 drops of damping fluid in the JMW 21.7 arm Tnx again!

P.S. - When comparing having the ring on or off I found it required a 0.04 Hz frequency change on the SDS to get speed to match. YMMV.

Perhaps some of the difference we hear with rim weights is due to whether we use a mat on the platter. On my Transrotor Fat Bob, there is no mat, just a vinyl layer which mates with the record. It is hard and has no give so the rim weight just makes sure the record is perfectly flat at is in contact with the platter at all points.
If a rim weight was used with a soft mat, I can see where it might press the record into the mat, causing a different resonant experience than just laying on the mat. I havent tried a soft mat on my Transrotor, and the only one I have is the Oracle mat which is quite soft and squishy.
for the record, I like the sound with the rim weight and center clamp.

As Manitunc and others here have suggested.........I believe that it may be the mat in combination with the rim weight which is the culprit here?
I removed the Millenium mat from my Raven AC-3 and placed the record directly on the copper top platter together with a centre weight and the rim weight.
All the life and magic, which had previously been sucked from the presentation with the mat in place, suddenly returned.
I am unable to repeat this experiment with the Victor TT-81 DD table as the aluminium platter has a raised outer rim to contain the thick rubber mat, and without it, the record's outer edge sits upon this rim and thus does not make contact with the platter itself.

Is the sound quality without the Millenium mat on the Raven but with the outer rim weight, better than a record without the rim weight but WITH the Millenium mat?
Not really.
So unless I'm playing a seriously warped record (and I only have a few which cause problems), why would I bother with the fuss and ceremony involved in the placing and removal of the outer rim?