Eminent Technology ET-2 Tonearm Owners

Pegasus - a few suggestions for hum

TT Checks :
Check the chassis/motor earthing on your SL1210- is it earthed to the wall ?
If so, then earthing to pre will create ground loop.
Check for continuity between TT earth and spindle to ensure platter is earthed. If not then there is an internal earth lead in the TT not connected.

Personally I've always got lowest noise by earthing the TT chassis/platter/motor through the power cable. If the TT chassis etc is earthed to the preamp you are putting noise into the phono ( assuming a single ended system ).

Arm Checks :
Unplug the phono cables/earths etc from the pre.
Check for continuity between your tonearm earth and the earth on your Decca phono cable with the arm not plugged into anything. If it is continuous then you will have an earth loop if you connect both the tonearm earth and signal cables to preamp. It is a long time since I had a Decca, but if I recall correctly some had the body and signal earth strapped at the cartridge end.

If the tonearm earth is truly separated electrically from the cartridge signal earths, then I would take the arm earth to the chassis and wall rather than the preamp. This is because any noise picked up by the tonearm earth would be dumped into the signal path in a single ended phono if you connect the tonearm earth to the phono pre.

ET2 Wiring :
My experience with single stranded silver wire was bad. Started picking up local radio stations and all sorts of rf. Twisting the wires helped but did not eliminate the rf.
I eliminated the rf completely by going to a silk copper litz wire. Even without twisting it in pairs there was no rf.
In both cases the wiring was continuous between cartridge and phono input.

Hope thats some help.

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Frogman - as u r a New Yorker, I wanted to mention I was very touched last night watching the NY Mets - KC Royals baseball game; when the camera focused on Billy Joel and the PA system played "Piano Man" with everyone singing.

What class !

Go Mets Go - those damn Royals took out our Toronto Blue Jays..... :^(

*****

Pegasus
Yes I have two twisted silver wires running left and right of the tonearm.

Another example of how the ET2 design allows you to be inventive and ingenious with the wiring. In this case Pegasus a picture would be worth a thousand words.

Dover....Started picking up local radio stations and all sorts of rf. Twisting the wires helped but did not eliminate the rf......

Attention Attention. We seem to picking up radio and RF.

Immediately invoke 007 maneuvering. and while at it please bring up that Faraday cage up from the vault as a backup.

This seems to be a very persistent strain Sounds like disco

(love the Bee Gees btw)

:^)

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******* YELLOW STICKY ET 2 THREAD - FACTORY SETTING OF PSI - REGULAR AND HIGH PRESSURE MANIFOLDS ************

I reached out to Bruce to help shed more light on how our manifolds work - both regular and high pressure HPM models. He responded and I believe answers the questions for our thread. Comments welcome.

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Hi Bruce

Was hoping to shed some light for ET2 owners on our thread regarding how the setting of PSI on our manifolds was done.

A couple of questions.

1) Are the set screws in the manifolds set up differently for different PSI's ?

2) Does setting a higher minimum PSI manifold (i.e. 19 PSI minimum), mean the spindle/manifold (gap) is smaller, tighter. How I came to ask this.

My ET 2.5 which you set up for highest possible psi 19. It continues to dominate over my digital. I also own an older ET2 High Pressure Manifold. I have noticed without air applied, that pushing my spindle through the manifold on the ET 2.5 is tighter, than the spindle going through the older ET2 manifold. The older ET2 HPM will also work with a lower psi, example 7 psi.

Appreciate any information you can provide.

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Chris,

The pressure drop across the set screws define the restoring force and part of the stiffness of the air bearing.

The tolerance between the Manifold Inner Diameter and the Spindle Outer Diameter determines the lifting pressure as a function of flow rate through the set screw. Without a restoring force or pressure drop across the set screw, the bearing will lock up, so you always need a higher air pressure in the manifold housing as compared to the pressure at the surface of the spindle.

The high pressure manifolds have a slightly tighter tolerance between the spindle and manifold, they also use a set screw with more plating to restrict the air flow around the threads to create the increased pressure drop (the difference between the pressure in the manifold housing and the pressure at the surface of the spindle).

It does not hurt to slide the spindle in the manifold bore without air, the resistance you feel may be the surface finish roughness on the hard coat anodizing as well as tolerance.

I hope this helps, thank you very much.

-brucet

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Happy Listening

Chris, that is exactly what I did . It helped a great deal with MM's which tended to have grounding issues although not nearly as severe as with the Decca, but with the Decca it is still a problem. MC's have never been a problem. For anyone who is interested, Michael Percy (website) stocks all necessary items including Teflon tubing, copper mesh and sleeving.

Oops! Sorry; this new iPhone is driving me nuts. Go Mets!