Eminent Technology ET-2 Tonearm Owners

I recently purchased a ET2 and now need to get it mounted on my VPI classic. A friend gave me the actual jig used by ET, unfortunately it is missing the bushing to drill the mounting hole. I'll take my time and get this right the first time. I hope.

Tim

Hi Tim
Congrats on the ET2.
Please let us know how you make out.
A number of folks here with many years experience with the ET2 & ET2.5 to help out if any questions.

There are also measurements on page 63 of the online manual on Bruce' website. from looking at the online diagram for the mounting hole.

1) From the middle of the spindle go out 8.258 inches (209.753) millimeters anywhere on the plinth that works for you and mark the spot.

2) Draw a straight line from the middle of spindle to this marked spot.

3) Go up 90 degrees from this line .885 inches (22.479 millimeters)

Mark the spot - that's where the mounting hole goes.

Welcome to the thread.
Cheers Chris

Thanks Chris,
I talked with Bruce today and put in an order for the missing bushing,magnesium arm,and high pressure manifold.
I will keep posting my progress.

Tim

Random Included Record Angles When they Make Records

You play a couple of records from your collection that are the same thickness. They sound different for some reason ? One might be brighter, the other a little warmer and full ?
This was not something I took much notice of many years ago with a very basic TT and tonearm. But as the TT and tonearm got better it became more noticeable.

We hear about how engineers in creating the master disc put their spin on how the records will sound. But how about the physics part of it. In addition to the final engineering differences record masters are cut with random included angles by the cutter. The angle of the cut when the record master is made.

http://www.aardvarkmastering.com/riaa.htm

from the site

Recording Groove Contour
a. Included angle 90 degrees + 5
b. Bottom radius 0.00025" max.
c. Width--Monophonic .0022"--.0032"
d. Width--Stereophonic, Instantaneous .001" min.
Minimum Inside Diameter of Recording 4 1/4"
Runout of Recording Grooves Relative to Center Hole .050" max.

Notice the record included cut angle standard that was set can be 90 degrees give or take 5 degrees....:^(

So there is no standard.

This is also captured in the ET2 manual and has been mentioned before. Bruce realized the importance of this and the reason he built into his arm VTA on the Fly that does not change parameters when used.

Vertical Tracking Angle Adjustment (VTA) - Page 51 ET2 Pt. 2 manual

"Several articles have appeared which address the area of cartridge performance. Vertical Tracking Angle (VTA) and Stylus Rake Angle (SRA). We have designed the Model 2 tonearm to optimize the vertical tracking angle of the cartridge.
The angle that the cutterhead is placed at when a record is cut results in an included angle in the final disc. This included angle must be duplicated with the reproducing stylus or distortion will result. The problem today lies in standardization of the angle by record manufacturers and corresponding standardization by cartridge manufacturers. Presently most records are cut with resulting vertical angles between 16 and 20 degrees. The average vertical angles of cartridges manufactured today is slightly higher than 22 degrees. The result of this mismatch is less than optimum performance for many cartridges."

Maybe those that use scopes should be pointing the camera - down - to the groove to try to figure out what angle has been used ?

Some ET2 owners I have talked to have locked down (tightened the screws controlling the VTA feature) to make it more rigid?

fwiw - I have sent an email to a couple record pressing plants as I am curious what determines what angle they cut at.
Is it based on temperature, record thickness, condition of stylus cutter ? Will post back what they say ...if they respond.

How important is the VTA adjustment to you ?

Great topic! VTA adjustment on the fly is, for me, THE most important feature of the ET2. I find it invaluable and use it all the time. The benefits for me have to do with fine tuning tonality, timbre, and the integration of the uppermost frequencies with the lower highs (sibilance, among other things) and the transition-range between the midrange and upper bass. I have not found (maybe simply don't care as much) dramatic changes in soundstaging due to different VTA settings as some have reported. Azimuth adjustment (also relatively easy with the ET) does make significant changes to soundstaging in my set-up.

Re the locking down of the screws that tighten the VTA feature: I feel that too much torque at ANY of the ET2's screws is a bad thing. I think the arm simply sounds better with moderate and similar torque at all the screws. I adjust the VTA adjustment screws so that the adjustment can still be made without loosening the screws; but with some effort. So, to make sure I am not stripping anything, I simply loosen the screws about a 1/4 (or less) turn, adjust, and re-tighten; just a couple of extra seconds for the procedure.