I posted a thread on the audioasylum and got a similar theme in that it was focused on improving the air bearing platter and tonearm. here are his comments. He has a signature model versus the standard model I have
Next thing to do is buy some real high quality air regulators to replace
the cheap ass screw valve which comes stock. I've tried various brands,
but have found that the Binks brand are more stable than most of the
others. I have 2, one for the platter pressure and another for the platter
pressure. I have the air pressure regulators and their gauges set into a
panel on the front of my TT stand, so that it is easy to see, and easy to
adjust. You'll need one that is low pressure for the arm, which runs
around 3 PSI. The other one will depend upon which arm manifold that you
have, either 20 to 25 PSI or 40 PSI. I have the higher pressure arm
manifold (Signature version #2) so I went with the highest quality Binks
model specifically designed for 20 to 50 PSI. The regulators were around
$75 each. Gauges were around $30 each, again Binks models.
If you haven't noticed, air quality and regulation is VERY important. Keep
this in mind.
I made a custom Purple Heart plinth for mine, that is 6 inches thick, which
really opened up the table ... much better than the original plinth. This
wasn't cheap. I gave my cabinet maker friend my plinth for a month to make
it all align perfectly. (You have to be sure that they realize just how
important 1 or 2 thousandths of an inch is in this case. (Although I
always wondered just how acurate the factory was ...)
As far as the arm is concerned, there is plenty that should be done. I had
a machine shop place a .002 spiral groove throughout the arm to improve
stability. Stock, there is just the air fitting and nothing else. Oh, be
sure that they have the arm tube and that the champhere the rough edges, of
course.
Replace the stock arm tube with Thompson Shafting. Any good machinist will
be familiar with Thompson Shafting. It has .001 run out in a 20 foot
length. It will not bend or distort like the stock hollow shaft does.
(This is why many Maplenoll arms will bind, and/or have tracking issues
half way through a record).
My stock arm tube was filled with a polymer type sound deadening material,
sourced from an old friend who works for NASA. It came in a plain brown
wrapper, so I'm sorry that I can't be of more help. I also wrapped the arm
tube with black duct tape, which really tightened up the focus and deepened
the stage.
I had a carbon fiber arm tube made for me by a friend who has an archery
store. (They use carbon fiber arrow shafts at $100 to $200 EACH!) Anyway,
he made me a carbon fiber arm tube from a broken arrow shaft that is really
interesting. Once again, it is duct tape wrapped for improved staging and
focus.
It's funny that Lloyd recommended using "Super Glue" on the arm/VTA adust
connection. I hope that he at least recommended the good stuff that
actually works that is horribly expensive. I used a very small amount of
JB Weld in that area. JB Weld is amazing stuff, and it is much, much
stronger than Cyanoacrylate.
The stock platter bearing needs to be "trued" by a competant machinist. Get
both plates trued. It cost me somewhere around $30 (in 1990's money) to
have them trued by a machinist friend. If you really want to get tweak,
have another platter bearing made with more surface area.
I am taking a little break from my tweaks but I have some interesting ideas to follow up on. Thanks again for all the thoughts.