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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John - yes, yes I was remiss in not giving you a nod for this wonderful tweak.

Chris - Wish I could come off as a pro and tell you balancing was a snap.  Alas it was not. It took a good deal of time and patience to acquire a neutral balance  for leveling before adding the weight.

Interesting you used the word "heft" in describing balancing.  Heft is a good deal of what this upgrade added to my listening.  The sound is fuller without any bloat or loss of detail.  Indeed, detail was improved.  Not the kind of detail that is clinical but the kind that lets you hear fingers on strings and spit in the reed.  All in all very nice.  

Let me know what you hear with the long plank when you get back home.

Re yellow jackets, I've been stung 3 or 4 times since retiring here to "deep rural" and had no problem except the pain.  This time I had an anafalactic reaction and ended up at the emergency room.  I am now carrying an epi pen.  Ahh, the price we pay for shunning civilization.

A few thoughts regarding longer i-beam and leverage:
- While the captive air-bearing has advantages in stiffness, the ET design with stationary bearing has only one point with centered forces within the bearing along the arm travel. This "allows" some maximal leverage at the beginning and end of the travel.
- Having a short i-beam compensated with more weight on the i-beam side increases (lateral) leverage.
  Eliminating the leverage on the air bearing by using a moving air bearing has some advantages, but a drawback too:
  Either one needs an additional flexible air-tube, which increases vibration coupling between arm and tt chassis, and also vibrations within the air feed. 
  Or one needs an open bearing with less bearing stiffness, like the (very good) Adanalog MG 1 arm, or the many Ladegaard variations incl. the Trans-fi arm. (see below)
- It is desirable to keep varying leverage at a minimum, a)  on the air bearing as well as b) on a sprung subchassis. The latter will lead to varying lateral desiquilibrium, visible as increased "slipping" from a balanced middle position to outwards gliding at the start and end positions of arm travel.

- So a longer i-beam reduces the leverage on the bearing, and on sprung subchassis. It improves balance of the center of gravity along the bearing travel.  And it increases vertical mass, which often improves the sound too.

- Regarding "optimal" vertical resonance I did put up the idea, that (maybe) there is not much useful out of phase bass information below 100Hz - this might not be the case... as increasing the (out of phase) bass bandwith below eg. 15Hz, by lowering vertical resonance seemingly still is audible.
- However, there is an end to that, probably below 10Hz because of subsonic vertical garbage information with a maxiumum around 5Hz. This contrary to lateral resonance where the main problem frequency (correctable) is not higher than 0.75Hz.

- Trans-fi arm:
I trust several keen and independent ears, that this is a superb design, technically by design and subjectively by constant tweaking and improvimg.
- the stability/stiffness of it's "open" bearing is still very good by it's v-shape which forces centering of the air bearing by help of gravity.
- the vertical knife edge bearing is a very good and elegant design with no bearing chatter, and with selfcentering by gravity too.
- "optimal geometric design practice" followed by ET keeps the vertical bearing axis on the same height as the tracing / platter level, This reduces FM wow induced by vinyl warp,
-  However, this is not without a price: Lifting this tracing level has it's advantages too, leading to improved bass: Trans-fi and RS labs ar examples. This is, because putting the vertical axis in line with the cartridge cantilever ((ca. 20-30 vertical degrees)) eliminates vertical pull on the cantilever bearing, reducing vertical resonance of the arm activated by dynamic friction changes by tracking vinyl, and by variable friction...
No free lunch therefore for ET... and the above mechanism is rarely looked at. 
@pegasus 
As always your posts are insightful.
re the vertical bearing axis, as set up on the ET. Do you see any reason why this could not be lifted to 20-30 degrees? (Warp issues aside.)
This assuming there is enough travel in the vertical slide. I guess that the  platter would need to be very low relative to the armboard.
Have you tried this?
Results?

cheers 
@pegasus 
What I didn't say, racing to catch a plane.
Would need to mount the goose neck upside down and likely drill and tap a new wand clamp thread in the adapter on the other side.
My guess is that this would sort the VTA adjustment.

cheers 

Richard did you not like my sled and boat analogies ?

Pegasus
Or one needs an open bearing with less bearing stiffness, like the (very good) Adanalog MG 1 arm, or the many Ladegaard variations incl. the Trans-fi arm.


I tell you snowmobile and boat racing on a slalom type course can be alot of fun .... the sliding and drifting around on turns is very addictive.

8^0