Eminent Technology ET-2 Tonearm Owners

Since no one has responded I will post my thoughts and see if anyone comments.

I think of it this way:

As the pressure is increased the volume of air used increases and this is dependent on the clearance between the manifold and spindle. At some point that escaping air will become obvious in two ways, one being the noise created and the other will be horizontal force on the arm at the end of travel.

The increase in pressure will also make the tube / manifold interface stiffer and I think this is what causes the increased performance. It seems to me the the stiffer the better as long as other factors such as oscillations, vibration etc. from the escaping air don't rise to a
level that they cause problems.

My arm is a very early version, so certainly not optimized for higher pressure, and I can feel the air escaping at 19 psi but I can't hear it yet. I have not tried to determine if it introduces significant horizontal force. As I stated in my post I could hear some of the life or vibrancy go out of the music when I increased the pressure but since I have tightened up the suspension I no longer notice this change.

It would be interesting to ask Bruce about this. I suspect that as the pressure increases he reduces the clearance between the manifold and tube. There must be a point of diminishing returns and I wonder where he thinks it is.

As I think back on what I did I also made some adjustments to tighten things up on the arm / mounting board around the same time I changed the suspension so that may also be a factor.

I should plumb the pressure regulator so I can sit at the listening position and adjust the pressure so it is easier to evaluate changes.

Hi David - please tell us what moderately priced TT means -budget range ? Does it have to be brand new ?

As I look at my naked TNT II without tonerarm I can see the one bolt that secures the ET2. The bolt is located about 2 5/8 inches from the nearest part of the platter and one inch above the spindle. Draw a horizontal line one inch above the spindle. a vertical line 2 5/8 inches beside platter. Where they join is the spot approximately just to give you an idea. It can be mounted anywhere "around" the platter as you only need a straight line to make it work.

It is a universal mount design only the one threaded bolt needs to be drilled unless you plan on running wires and the air tube through a plinth as well.

You can get info by going to the Eminent Technology website.

Go to Support, Manuals ET2 Manual Part 2 - See Pages 62-63

or

The manual can also be downloaded from Vinyl Engine
ET-2 Manual

Let us know if any questions.

Cheers Chris

Apbiii, I have never experienced what could be described as a decrease in performance by increasing the pressure; although I am sure there comes a point, as I think you found out with your regular manifold, at which the arm does not work optimally due to the higher pressure. The reason I like 17 psi and no higher is that because of the way my system is tuned, 17 psi is the most complementary. Higher pressure produces a sound that is too lean and overly controlled. I have no doubt that in a different system, with my cartridge, the arm would sound better at the higher pressure.

I am intrigued by your observation that with the rubber ball suspension
(lower compliance) you don't hear as much of the dulling of the sound with psi above 15. If your non-high pressure manifold is given higher psi, it's possible that the resulting instability due to the "turbulence" in the larger gap between the manifold wall and the bearing tube is made worse by the higher compliance of the tt's suspension.

A couple of other comments/ observations that come to mind about the arm:

-The capillaries do get clogged over time. Years ago I experienced a gradual dulling of the sound with eventual poor tracking. The problem was clogged capillaries. It is tedious but not difficult to clean them. DO NOT do what I have seen suggested in a couple of forums. Do not try to clean them by forcing alcohol through "the system". I tried it and made matters worse. The manifold must be removed and all the capillaries unscrewed off the manifold and cleaned individually with alcohol. The difference in sound from doing this was significant.

-Do not over tighten the two bolts that secure the manifold housing to the pillar. In some arms (mine) the holes for the bolts are tapped too long and will actually go into the inside of the manifold housing and dislodge the piece of tape that is in place to seal and make airtight the housing. The result is escaping air and decrease in pressure.

When are you guys coming over? :-)

Siriusly -hehe- when I had Bruce, no -- not that Bruce -- from Stereo Unlimited in San Diego set-up my deck, ET2 with VPI HW-19 Mk.IV, it sounded wonderful...

I'll get back to that sound, someday!

Thanks all for the great exchange of information :-)

Vbr,
Sam

Hi Sam - Welcome to the thread. The one where tonearm owners need life support for their straight lines; all in the name of no tracking distortion and natural sounds. Heh, heh

Two Bruce’s in HI FI eh ?

Sam - Don’t you have a leaky original pump ?

There is probably an ET2 owner near you - otherwise it is 0 degrees Celsius here – about 32F – what if I get a work assignment there for a week ?

I’m sure Slaw can provide many tips for that VPI HW19 MKIV.

APBiii good information - I will respond with my 2 cents worth. I have been doing some experimenting.

Frogman - can I ask what you think of this Empire 4000 DIII on the ET2 ? Don’t you also have one? Did u use it long enough to form an opinion? How does it compare to the many cartridges you have had on this tonearm?

Cheers