Uni-Protractor Set tonearm alignment

Dear Thuchan, Jazzgen,
I mounted my 12” JMW memorial on an armpod and set it up on another table on weekend for the Jrs. experiment.

It took all of two minutes – no numbers or calculations - I put the cartridge in the VPI tonearm head - nice and straight the way I wanted it to be held - firmed up the bolts.

Then I rotated the JMW arm hinge and the armpod until it lined up perfectly with the VPI jig.

I have found that JMW arm works best for me with no turn of the wire.

Sorry to digress away from the thread theme.

Cheers Chris

Dear D -
That Apolyt is quite the platter and those arm pods. :)

My extensive testing of the 2.5 showed me that 6-8 working psi is a very safe albeit too LOW psi for the 2.5 to show its stuff. So am not surprised at your earlier remarks.

I found the ET 2.5 starts coming into its own around 16 psi to about 20 psi. My findings were later confirmed by Arthur Salvatore who told me his members recommend 19 psi. "Above 19 psi and the arm starts to lose information".

At 19 psi – the ET 2.5 has phenomenal PRAT, Bass Attack, HF, sounds the most natural. It competes with arms well above its $2900 US purchase price. I very much recommend to those with the ET 2.0 to have them upgraded to the 2.5 bearing along with a Timeter Aridyne medical pump available on Ebay. These two mods make the basic ET 2.0 arm are a giant killer.

Good luck and much success with your Uni D.

Cheers Chris

Dear Dertonarm.
Spring rain kept me from chores so I did some reading on Agon looking to learn. I read through this Uni thread from the start and came across a post you made on March 11 that is puzzling to me.

Specifically you said.

“the linear tracking tonearms - in any incarnation we have seen so far from Rabco, Denessen, Goldmund, Versa Dynamics, Air Tangent, Eminent, Forsell et al -displayed mechanical issues, periphery problems and stability problems which did always crippled their undisputed tangential advantage.
…

Most audiophiles who ever ventured into tangential tonearms later moved to tonearms with 11" or more effective length to approach kind of "best of both worlds".
…

I have had all the above named tangential tonearms in most all their incarnations in my system in the past 30+ years.”

Wow – quite a statement. Two questions.

1) Can you tell me who “we” is when u say "in any incarnation we have seen" ? Is that an audiophile club?

2)
I have owned the ET 2.0 and now 2.5 arms for the past 5 years so your statement caused me some despair. Is there an unknown problem I am not aware about? Would you please be so kind to enlighten me for the “Eminent Technology arm specifically” that you owned - about the stability, mechanical, etc… problems you had.

I found alignment tools provided with these linear arms get you to about 75% of their potential. The rest is trial error tweaking by ear. Personal discussions with Mr. Thigpen have confirmed this. You need to experiment and try different settings. See what u like / dislike. Once past the initial tool settings it is all FEEL, ADJUST, LISTEN. Definitely not plug and play but once set up – you can forget about it without issues I have found.

All problems I came across in my earlier days with the ET arm, and in talking with other folks about linear tracking arms in general - other than pump/air problems – easily fixed - have always been related to actual user errors and the lack of "total knowledge" about the arms and the way they work – thus leading to improper setup. After 5 years I am still learning about my ET arms and how they work.

I look forward to hearing back from you when it is convenient on "your ET specific problems" as you say u owned the ET. You did not say whether it was the 2 or 2.5 version.

Lastly does the Uni package contain any tools that would be useful for lining up linear tracking arms ?

Thank you. Chris

Thx for the quick reply D and clarification on the lack of issues other than pump sources with the ET. I have had no cartridge issues in 5 years and it is my main arm.

Is the UNI tangential tool similar to the ET supplied one. I am looking for something that would let me square the line better from the spindle to the bottom of the straight sp10 casing. I am using a homemade extender right that does the job but am curious.

One final question.

You said

"The ET 2.5 improves considerably with increased air pressure up to a certain limit". It does deliver very good bass with a lot of "body" - but not quite the quality I seek."

Are you able to recall what platform/table you mounted the 2.5 on and what PSI you registered at the air bearing, not the pump source.

Thank You Chris