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.
Eminent Technology ET-2 Tonearm Owners
Where are you? What mods have you done ?
I have been using these ET2's for over 9 years now.
I am still figuring them out and learning from them. They can be modified in so many ways. Bruce Thigpen laid down the GENIUS behind this tonearm over 20 years ago. Some of you have owned them for over 20 years !
Tell us your secrets.
New owners – what questions do you have ?
We may even be able to coax Bruce to post here. :^)
There are so many modifications that can be done.
Dressing of the wire with this arm is critical to get optimum sonics along with proper counterweight setup.
Let me start it off.
Please tell us what you have found to be the best wire for the ET-2 tonearm ? One that is pliable/doesn’t crink or curl. Whats the best way of dressing it so it doesn’t impact the arm. Through the spindle - Over the manifold - Below manifold ? What have you come up with ?
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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 |
Richard, interesting comments. Eventhough I settled on 18.5 -19 psi (at the arm) based on what my ears tell me sounds best in my system and not simply what my HP manifold was designed for, that pressure is (coincidentally?) about .5 psi above the pressure at which the check valve on my surge tank starts to release some air without fully opening. As the pressure is increased further the released air increases until the spring loaded valve opens fully (at about 20.5 psi or so AT THE SURGE TANK). Makes me wonder if the reason the arm sounds best at that pressure is not only that it is the ideal pressure for my arm, but also that the released air has a similar effect as what the Motronix accomplishes. Thoughts? |
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