Eminent Technology ET-2 Tonearm Owners

@ketchup 

Thats why I still run the aluminium arm tube with heat shrink and internal damping removed - keeps the horizontal mass as low as possible and less smear with the h/s & foam removed.

Hi Guys - so I conversed with Bruce this past week on this topic.The conversation is attached below. My personal experience is this.

Anyone into vinyl seriously who sets up their own rigs could probably become a physics major. All the considerations for vibrations and resonances in the room, and they start with that cartridge wiggling in the groove generating a signal. It doesn't get more analog//mechanical than that. Everyone on this analog forum knows by now, that Linear Tracking guys are a certain type of personality. We are not happy that a pivot tonearm can only track properly at two points on a record, we hate anti skate like cancer;  however many of us have secondary setups (we call them secondary) and they include pivot tonearms. But we have (actually) heard the differences between them, and when set up properly you can't beat the resolution of ET2,  2.5.  Clean sounding records start to finish. 
Regarding the recent discussions, I have been using a Mag wand for a long time now with no detriment to the cartridge. My personal experiences is concerns over the added weight are negligible and what is more important -  is proper setup and matching high and low compliance carts to their better wands. Aluminum - High Compliance Carts , Mag - Low Compliance Carts. Many have personally modded the aluminum wands to meet their needs. It's all good   
I attach discussions with Bruce this week on the topic.  

************************************************************************    
Hi Bruce
> 
> A question from someone.
> They are worried about the heavier mag wand over the aluminum in
> regards to the cartridge cantilever stress, since all records are not
> perfectly round. They think the cart will sway more back and forth
> more with the Mag wand causing cantilever stress.
> The owners manual is clear not to play records that are badly out of round.
>
> Can you provide me with an explanation regarding the forces at play.
> I understand how the aluminum wand works better with high compliance
> carts, and vice versa low compliance carts for the magnesium wand.
> Thanks Chris

Chris,

     The untold parameter of a pivoted tonearm: To minimize tracking
error, pivoted tonearms were lengthened with a bend in the wand, or by
mounting the stylus at an angle in the headshell. The frictional force
of the stylus in the groove wants to straighten out the bend or crawl up
the records inner groove wall. When using anti skating with a pivoted
tonearm to prevent inner groove wear, regardless of mass, pivoted
tonearms bend the stylus with an opposite side load force of between .1
and .2 grams per gram of tracking force, the tonearm shaft is being
twisted outward (as viewed from above) with this static load which goes
through the stylus suspension, but the percentage of creep on the inner
wall of the record groove actually varies with the passage loudness or %
groove modulation. So you are constantly bending the stylus while only
marginally solving the problem.

     With the ET-2 the side loads to accelerate the tonearm at .55hz
(33/13 RPM) are less than half of those values for an eccentricity of
.0312 inches (1/32 inch) and are a linear function of record
eccentricity. The cartridge cantilever suspension sees much lower loads.

     So as you add mass, this side load value of the ET-2 goes up
linearly, but is always less than using any pivoted tonearm with anti
skating.

    I hope this helps  - brucet

******************************************************************************

And remember the ET 2.0 and 2.5 are unique in design unlike any other linear tracker. This has been covered in length on this thread.  The numbers Bruce refers to were actually tested by him in a lab and apply only to his tonearm.   
 

My reasoning for weighing the magnesium and aluminum arm wands is that I just removed my aluminum arm wand to install a magnesium arm wand.  The heavier magnesium arm wand should be a better match for my low compliance cartridge.

Does anyone know what kind of adhesive is used to attach the metal leaf spring to the I beam?

Email Bruce and he will give you the info.

Are you using the newer long I Beam ?
Recommend anyone using the original short I Beam get Bruce to send you (single and double) leaf spring long I Beams. They reduce the counterweight requirement by half, and increase vertical inertia.

@ct0517 I'm sure it's somewhere buried in this thread, but how long is the long I-beam?  I have one that's 60mm and one that's 70mm.  Is there one that's longer than 70mm?