Micro Seiki MA-505 variants - any oracles around?

I wonder if somebody out there possesses encyclopaedic knowledge about the Micro Seiki MA-505 variants and can tell me:

1. if the MA-505X is similar to a Mk I, Mk II or Mk III?


2. if the MA-505X does indeed have silver wiring and if that's the only difference between it and the regular models?

Fingers crossed and thanks in advance!
There is a lot of confusion over the differences between various MA-505 models.  I can only provide you with what is my understanding and others may correct me if I am mistaken.

MA-505 Mk I - the original MA-505 dynamically balanced tonearm.  A 9" "S" arm w/ copper wiring.  Still very good by today's standards

Mk II - The MkII is am improved version of the MkI

MA-505 Mk III - 9" straight tonearm w/ copper wiring.  It was designed to mate with very low compliance cartridges which were all the rage in the 1980s

MA-505 L - a 12" version of the Mk II tonearm.  I have never seen one that was based on the Mk I but maybe someone else has.

MA-505 S is a 9" MkII arm, supposedly wired with silver wire.  Note: Maybe - I once owned an "S" arm and when I rebuilt it I found that the internal wire was silver-coated copper.  Maybe mine was an anomoly

MA-505 LS is a 12" arm version of the MA-505 S

MA-505 X - a 9" MkII arm featuring a heavier arm base

MA-505 XII - improved version of the MA-505 X.  Includes heavier arm mounting bracket and oil dump mechanism

MA-505 LX - 12" version of MA-505 X

MA-505 XS - 9" MA-505 X tonearm w/ silver wiring

MA-505 LX II - an improved version of the 12" MA-505 LX.  Same improvements as the MA-505 XII

Wow! Impressive knowledge of that subject.  I once owned what was at least a Mk II version and foolishly sold it without ever having used it. I would only add that for the Japanese, "S" is not always an indication of silver wire.  For example, the Fidelity Research tonearms that bear an S suffix are not necessarily silver-wired, unless there is a separate label so indicating.
Wonderful stuff br3098, thank you so much for taking the time to write it all down!
I recently picked up an MA-505X, seemingly in mint condition (time will tell I guess) at a relatively reasonable price, but wasn't entirely sure exactly what I was buying due to the plethora of models in existence and an almost complete lack of dependable information.
I was under the impression that the 505X had silver wiring, but whether or no makes no particular difference.  I've never owned one but enjoy the sound of it a lot in a friend's system, so I decided it was time to check it out for myself.
Thank you once again, I'm most grateful.

I forgot to add that (apparently) the XII and LXII tonearms also featured silver wiring.  Again, color me skeptical if you own one you tell me.

But all in all the MA-505 line are very good tonearms; if not equal to those in the highest class.  I find them to be unequaled on classic Japanese DD and belt drive decks, which is what they were designed for.

Indeed, I'm sceptical too.  Fortunately I don't particularly care and in any case I'm unlikely to ever find out unless the arm turns out to be defective and needs to be disassembled.

Mine will by necessity be mounted on a Spacedeck, but presumably it will perform well there too.
How do you like the performance of the arm? What Cartridge are you using?

MA-505 Mk III - 9" straight tonearm w/ copper wiring. It was designed to mate with very low compliance cartridges which were all the rage in the 1980s

CORRECTION: It’s the other way around. This is the arm with 7g effective mass and tracking force from 0.25 - 3g. I believe it was designed for HIGH compliance cartridges in the 80s (not low compliance), but tonearm can support a cartridge even with 4-16g selfweight.

P.S. Another interesting arm made by Micro Seiki for Luxman is TA-1 for high compliance cartridges. Static balance system. Cartridge weight range 2 - 16g, tracking force range 0 - 3g, effective length 240mm. Antiskating adjustment, cuering system, arm-base stabilizer. Made in the 70’s by Micro-Seiki for Luxman Corporation (Osaka, Japan).
chakster, you are correct of course.  My bad.  I meant to say that the MkIII tonearm was designed for HIGH-compliance cartridges.

Thanks for the catch.

BTW the arm on Pioneer Exclussive P3 and related top of the line Pioneer turntables was also designed by Micro Seiki and has some similarity with Micro Seiki MAX-282  
Just to add to the variants of the MA-505 is the 
OEM arm found on Micro Seiki DD-40 turntable, still identified
as an MA-505 although different from the arms sold
on their own. 

Ok, so have any of you used the X version with a Koetsu Cartridge and if so what were your thoughts?