Eminent Technology ET-2 Tonearm Owners

Frogman: Your point is well taken and one that I failed to address: the possible differences in manufacturing processes of the wide variety of pressure guages. I do listen in a small room/nearfield which is conducive to my hypersensitivity on a wide range of issues. By the way, do you or does anyone remember the ET upgrades offered and reviewed in 1995 by Roger S.Gordon? He reviewed a (Montronix Acuflo Air Regulator). This is what I have, only the DIY version. It is way overdone for 'our' needs but the Montronix sold for I believe $400.00 then, I got the DIY for $150. In his review were the following:
Build-it-yourself-air pressure regulator
ET II Large diameter high pressure manifold
ET II Magnesium Tonearm
Damper trough
Bright Star Padded Cell

His conclusion for most Bang-for-the-Buck was the BIYS air pressure regulator. FWIW.

Ct0517: I ordered my 2.5 so many years ago and without the benifit of this forum that I couldn't tell you what mine is specifically built for. I actually emailed Bruce about this a couple of years ago and his only answer was that it is probably built for the way I'm currently using it. I guess this means no detailed maufacturer/sales info on file record. Anyway, all I know is what I hear and that's good enough for me.

Thanks again for your input on my compressor issue. By the way, as we exceed over 1000 hits here, I want the thank you for your vision and your extraordinary follow-through regarding this thread. It's easy for one's efforts to be overlooked. You are to be commended Sir!

Slaw, I remember Gordon's article well; that's how long I have had my ET. I was always intrigued by the Motronix and a couple of years after the article appeared I searched for one without luck. What I remember the article did not make clear, other than the claimed benefits, was what exactly the Motronix did other than provide presumably more accurate control over xthe air pressure? I seem to recall some reference to it releasing some air in a controlled fashion with the supposed benefit of a smoother air supply to the arm. Can you shed some light on this? Thanks.

Frogman and Slaw.
You planted a seed when talking about the Montronix regulator and controlled air bleed.
I have just teed off a 1/4" needle valve in between the compressor regulator and the second in line regulator.
The tee is configured such that the compressor output is fed straight to the needle valve and the second regulator is connected at right angles. Such that the air going to the arm has to turn 90 degrees.
The needle valve is just cracked open, bleeding only a tiny amount or air to atmosphere. This does not alter the pressure at the arm since there is a significant delta P between the two regulators.

If your regulators are of similar stability as mine you can expect greater solidity and dynamics and just plain better sound.
This test was done when the compressor was off so the air supply was ex the high pressure storage tank only.

Theory is that the regulator must be dithering about its setting. The needle valve, being non compensated clips the peaks of this pressure perturbation.

I found a rare reprint or Myles Astor's TAS review of the Motronix Acuflow Air Regulator:

http://www.whatsbestforum.com/showthread.php?5653-Linear-tracking-Turntables!/page3&highlight=motronix

Apparently, two of the people involved with designing and reviewing this unit are still involved in audio. Miles Astor, PhD is Senior Assistant Editor at Positive-Feedback Online and Marlen Mogilever, PhD, who is mentioned in the TAS article as being "of Motronix" is now the principal designer at Blueberry Hill Audio:

http://blueberryhillaudio.com/index.html

After reading the TAS article, I realize that this unit was more involved than what most of us are now using, i.e. two spring/diaphragm regulators with a surge tank in between. I wonder if we contacted one or both of them that they could/would give us enough detail to be able to reverse-engineer the Motronix unit or, at least, to mod our existing setups to duplicate the Motronix unit's functionality?

Dave

Received my ET package from Bruce yesterday.
Will post up pictures over the weekend of my air set up along with the ET-2.5 on my system page.