Garrard 301 - Project

I have 3 TT s in PA slate and am very pleased with performance but I did not sample a wide variety of materials so would not claim slate is absolutely the best. So what do you prefer, fsonic?

Hi Lewm. I would love to claim that I have tried a slate plinth with either my TD124 or 301 but that would not be true. So when I responded above that it is not true that slate is optimum, I did so brashly and from trusted wisdom. That said, I went through a series of turntables starting in the early 2000's and then started focusing on idlers in the last fifteen. I have talked at length with many experts. I have experimented with several different wood plinths and with multiple platters on both of my idlers. Unfortunately our niche (idler drive turntables) within a niche hobby does not result in very much scientific analysis of matters such as vibration damping properties of alternating layers of birch vs. slate. If you do some research you will find some good threads on the Lenco Heaven site. Slate is not known for absorbing or damping motor vibration or any other vibration. Our lizard brains just assume that slate being heavy and massive it must be good for something like a plinth. 

I have no doubt that a Garrard 301/401 can sound very good mounted on a slate plinth. My unsupported belief is that the sound you will get is not consistent with the best characteristics of idlers. To draw an analogy, why would anyone take a Harbeth loudspeaker and convert the enclosure from wood to Magico-style alloy keeping everything else equal?

@fsonicsmith

I know we’ve posted on this before in previous threads. The more things change, the more they stay the same, huh? I’ll reiterate for this thread. As far as comparing the two plinth technologies, I have a 5 x 13 layer solid Baltic birch ply 12" arm plinth topped with 1/3 solid walnut and "veneered" with 1/2" maple. I also have a 50mm PA slate plinth. 2 Audiograil 401s. Modified with 3rd party idlers, bearings and platters. 2 Jelco TK 850L arms. Same Decca London cartridges. They both sound great. I’ve compared them side by side. The slate one is more transparent, airy and neutral, gets less confused, blacker backgrounds, faster etc. I would temper this with the clause that if one likes a warmer, tubier sound, the slate may be the proverbial cup of tea. As far as damping, soft PA slate (amongst other) is made up of layers which defract and absorb noise.

Slate is not known for absorbing or damping motor vibration or any other vibration.

Fsonic, My own Lenco is mounted in a 50mm slab of PA slate. However, it also benefits from a PTP top plate, a hefty after market bearing, a platter that has been painted with vibration reducing black paint, speed that is regulated by the Phoenix Engineering gear, and two high end tonearms.  So I am hardly in a position to say that the slate slab alone is responsible for its excellent performance.  But it doesn't seem to hurt, either.  I can say I replaced a John Nantais re-plinthed Lenco with the one I have now. the JN unit did not benefit from the PE power supply and Roadrunner, and the slate unit is better for whatever reason.

I don't use Slate for any purpose in HiFi, but have at one time been interested in the material and as a result, own a very heavy Slab, probably from a Seam that was close to 2500Kg+ per m3.

I no longer express an interest in Granite as a Plinth Material, I have many years experience of it used on a 401, and through the 401's new owner being a friend, experienced the 401, used on a selection of Plinth designs of which I preferred the lighter designs, in either a Wood Mass with Damping Pockets or as a CLD Design.

I know the 401 Sound very well and the most it has impressed me is during one of my last encounters of it in use, when the 401 was mounted in a Three Way Compressed Bamboo Board cut to be used as a Plinth.

I stand by my statement made at the time of the demonstration, being that I have not encountered a 401 that could create such a good impression.

With my better understanding of materials today, I do know that the Three Wat Compressed Bamboo Board can have a Damping Factor of 2 - 5 depending on whether the size tested is a Sample dimension or a Plinth Dimension.

That as a measurement for a Sample is 10x improved damping in comparison toa MDF Sample.

Slate as a Sample has a measurement of 0.017, which is one the last measurements one would select if choosing a material with highly effective intrinsic damping. The Bounce Back of Energy transferred is going to be evident, I will state audible, if compared to a material being used with damping properties that produce little or negligible bounce back of received energy. 

The material I am now an advocate of, and for a period of time have been transitioning to for various roles. Especially as a Plinth Material, Sub Plinth Material, Equipment Chassis and is the material that will most likely supersede most support materials used in my system is the material referred to as a Phenolic Resin Impregnated Densified Wood, of which it can be discovered from the Brand Panzerholz and Permali and in my case are both owned.

A Sample   of Panzerholz and Permali has a Damping Factor of 4 and a Plinth Dimension of 25mm Thick Panzerholz has been measured with a Damping Factor of 7.

There is no Bounce Back that is audible from these Damping Factors, and the Dissipation of Energy transferred is one of the Best Measured as well.

I will not suggest a Stone, Plywood Board or MDF is a inferior plinth, each material can be quite stable. I am sure they have their fanboys for how the sound produced is assessed.

I would myself have a Compressed Bamboo over any of the above, as I know how it has impressed me in relation to what I know about Stone and Plywood Board Designs.

Over all the above I now know without reservation I would have a Phenolic Resin Impregnated Wood Board, I have heard this compared to Marine Plywood, MU25 Plywood and the Panzerholz Plinth was instantly discernable for the improvement  it offered. 

@pindac @noromance @fsonicsmith 

all interesting.  My only experience is of Woodsong plinths.  Didn’t realize, but apparently they combine birch ply, panzerholz, and slate, all in one design.  (search for an Art Dudley piece from June 2016 describing a Woodsong 301 plinth.) Does that mean I win?  (lol!  quite sure we’d all love each other’s decks!)