Garrard 301 - Project

And your method for arriving at a numerical damping factor with plinth materials, Pindac?

We also have to ask where is all this spurious energy coming from? Also keep in mind that European slate is different from Pennsylvania slate, just as PA slate is different from Vermont slate, etc. ( I’ve had SP10 mk2 plinths made of both. PA slate was better.) OMA proudly use PA slate and also natural hard woods from PA in their speakers.

Slate is layered such that its energy dissipation in the plane parallel to the layers would be very different from its energy absorption perpendicular to that plane. There you would probably get more “bounce back “. But does it matter? What spurious energy is attacking the surface perpendicular to the plane of the layers? In the end also, slate provides lots of dead mass, which I think is beneficial. Finally it’s impossible to resolve the question by back and forth discussion. I built my plinths 10-15 years ago, I’m satisfied, and I’m not starting over with plinths.

Typing on my bespoke cell phone made of densified wood.

What I have been trying to say, particularly with my Harbeth speaker enclosure analogy, is that in my very humble opinion trying to make a 301 sound "airy, transparent, neutral, fast" et al is trying to turn the 301 into something that it is not. Why would anyone take an Audi R8 and install a lift kit and all terrain tires on it? If you want airy, transparent, neutral, and fast, any number of current era TT designs deliver those qualities in spades.

The 301 as a result of its design has a more relaxed truth of timbre and tone character. The powerful motor coupled with original very light platter also gives it "snap" to transient's and a strong sense of propulsiveness (my spell check denies that as being a word), but without sacrificing the relaxed overall touch and tone. 

Why not play to the strengths of the design rather than ameliorate them as if to mimic a modern sophisticated belt drive or DD table? 

In my case I did, largely out of blind luck and intuition, substitute a heavy duty all- brass bearing assembly and the Steve Dobbs alloy with copper top platter. At one point I was using the Classic HiFi brass platter that weighs 12kgs, nearly 25 lbs. 

https://www.classichifi-shop.co.uk/product/brass-platter-20-mm-oversize/

I much prefer the sound of the Dobbs platter. The heavier platter eliminated all sense of excitement to the sound. How can this be, one might ask? It is rotating at the very same speed and with all that inertia it ought to sound every bit as authoritative. I have no answer. Except that maybe just maybe the resonance of the all brass platter bouncing back through the LP and back to the stylus does something adverse to lively sound. And maybe just maybe all that mass and inertia can not overcome stylus drag and it's effects whereas letting the powerful motor exert itself through a relatively light platter overcomes stylus drag. 

And yet another factor is the inherent added friction of a very heavy platter on the bearing assembly. 

All any of us can do with the 301 is experiment. If a slate plinth mated with the 301 sounds the way you want it to sound I can not argue that you have made a bad choice. 

@fsonicsmith I completely understand where you are coming from. In fact, I agree with you. That’s why I have two in the main area—wood with original platter and slate with the other stuff. Note that I am using 401s with the better motor (for stereo) so torque may be less of an issue with a heavier platter. I use the PAC 20mm oversize aluminum platter on the slate with a SPH grease bearing. Far better soundstage and cleaner bass.

Anyhow, I believe that the difference between a well-sorted wood, and a well-sorted slate unit is far less than a non-refurbished unit with an old SME arm on a poor support. Isn’t it all about getting the info from the grooves in the most musically satisfying manner possible? 

Steve DobbsDobbins?

@lewm My days of Ping Pong with you are from this post onwards over, especially on the subject of your preferred plinth material, in relation to my ongoing interest in Plinth ,Materials, where I have for the present settled on a Phenolic Resin Impregnated Densified Wood Board as the Plinth Material.

There are Links posted by myself for quite some time that shows the Damping - Dissipation Data for many materials selected for a Plinth and other Structures used in the field of audio. I will not be supplying these to you, that search is now for you to satisfy yourself.

My two pennies worth, strongly suggests Slate Samples of same dimension from all over the World will measure at very closely to 0.017, which will have substantial Bounce Back as an inherent property. This is very different to your very Layman description of Slate Properties.

Again if a  Phenolic Resin Impregnated Densified Wood Board produced anywhere in the World, if the same dimension will measure similar, especially with 4.0 being the reading for a 4" x 4" x 1/2", which is substantially more attractive as a materials than all others known to be used for structural purposes in the field of audio.  

@noromance It is good to see your inquisitiveness has taken you to places where modern approaches are being adopted and the benefits are discovered. The SPH Bearing with the Non-Metal on Metal design is one I know very well, and one I was instrumental in having a Composite Spindle Design produced for, which a friend now has in use for their Idler Drive adventures. 

Ok. From now on I will accept your pronouncements without question. But I won’t be able to reproduce your data for slate or any other material, because you refuse to explain your methodology. Also, in what way are you not a “layman” when it comes to materials science?