Variations of the Micro Seiki MA505 tonearm

Hi Lewm,

Congratulations on your purchase.

The only Mk-I I've seen did not have a lateral balance weight either, so I can't report on its benefits.

Lateral balance refers to equal left/right loading of the bearings and not to azimuth.

Yes, the 505 Mk I is capable of azimuth adjustment, but only if you purchase an accessory headshell like the one sold by Sumiko, Ikeda, or the Artisan Audio headshell I'll soon be stocking.

None of the 505's do VTA on the fly, but they do VTF (tracking force) on the fly.

The Mk-I and the two Mk-III's I've experienced all use the exact same VTA locking mechanism - the rotating wand which tightens a collet around the arm stub.

With respect to tracking force, I always calibrate the tracking force with these arms. The procedure is simple: set the dial to the desired number (let's say 2.0 g for example) and then adjust the counterweight until your digital scale reads out that same number (e.g. 2.0 g). In this way, you know that your starting point is spot on - even if the dial isn't perfectly zeroed out or linear.

Cheers,
Thom @ Galibier

Thanks for the informative responses. Just to be clear, tho, the sample I own is a MkIII with a removable straight arm tube. Since it is of this late type, can it utilize the optional azimuth-adjustable headshell that you (Thom) describe? On earlier versions of the arm, with the S-shaped tube, I can clearly see in photos that the headshell is detachable; moreover it is of a different shape and size compared to the miniscule head shell on my MkIII arm tube. On the MkIII it does not appear that the headshell is meant to be interchangeable. I was also interested to read Thom's declaration that none of the 505's do VTA on the fly. Mine certainly does not, in agreement with what Thom wrote, but others that have been for sale are often described as having this feature. In photos, it looks like you can twist the stem that attaches to the locking collar to obtain a minimal up or down movement of the pillar without entirely loosening the grip, on non-MkIII versions. On the MkIII, the stem is a single solid piece that can only be used as a lever to loosen the collar entirely. Anyway, it's a beautifully made piece of gear, and I am happy to own it.

I may have to disagree with Thom on this one, unless I am not understanding his statement. I have the MkI version and it allows VTA (as well as VTF and anti-skating) on the fly. On my arm I twist the lever to loosen it, then I can move the lever to the right or left which results in the arm being raised or lowered. While the on the fly feature is nice I would not recommend it for anyone who does not have an extremely steady hand. To much room for error leading to potential cartridge and other damage. I did it once and feel fortunate I did it right. Never again though.

I have the S shaped tonearm and my experience from Thom's is different here as well. After attaching the MS headhsell to the arm I was able to adjust the azimuth by twisting the shell. At first I thought I may not have turned and tightened the collar properly, but it appeared I did and was still able to move twist the headshell. Maybe I still haven't tightened it properly???

Dear Clio09, Your description appears to be correct based on photos of the early versions of the 505 found in Micro Seiki publications and on-line in For Sale ads. Looks like, as you say, you can twist the knurled knob at the end of the stalk that projects out from the locking collar for the arm post, so as to be able to adjust the height up or down by a few mm's at least without fear that the arm will come completely loose and fall to its base setting. My MkIII does not have that capability. Maybe MS thought this was an unsafe feature and therefore delete it from the MkIII.

Lewm,

On Vinyl Engine there is a copy of the MkIII instruction manual. You do not have VTA on the fly. You have to loosen the lock lever to make the adjustment. There is even a warning to make sure you somehow anchor the arm in the process so it doesn't drop quickly and damage the stylus or record.

On the column of the MkI there is a slanted spiral groove etched into the column. The nub at the end of the lever fits into this groove. So when you slightly loosen the lever, it provides the ability to slide the arm up and down. The danger is the nub is small and if it comes out of the groove the arm will sink quickly.

I imagine you are correct that MS felt the original design was not fool proof enough. So they decided to replace it with something a bit safer.

As for azimuth, it does not appear you can make the adjustment via the headshell. However, can you loosen the screw that tightens the arm tube and rotate the arm tube to make the azimuth adjustment? My Kuzma Stogi allowed for this type of adjustment. Maybe the MkIII provides the same capability.