Variations of the Micro Seiki MA505 tonearm


I recently purchased an MS MA505 MkIII tonearm. This unit has the straight, replaceable arm tube, but unlike earlier versions of the MA505 (with the S-shaped arm tube) that I have seen in photos only, it does not have VTA "on the fly" adjustment, nor does it have the weight that extends out on a horizontal post from the vertical bearing on the inner side of the tonearm, which is referred to in early MA505 manuals as the "lateral balance weight". The various MA505 manuals do not use the term "azimuth" anywhere, but does the lateral balance weight allow for azimuth adjustment? And if so, why oh why did MS eliminate both VTA on the fly and easy azimuth adjustment when they went from the MkII to the MkIII version of the MA505? As far as I can tell, one cannot adjust azimuth at all with the MkIII version, except by the usual primitive method of shimming the cartridge body. Thanks in advance for any relevant information on this subject.
lewm
I used to have a 505S (S stands for silver wire) years ago. I don't remember its azimuth can be adjusted on-the-fly. The lateral balance weight was designed to counter horizontal arm movement in case the table was not perfectly leveled. It has nothing to do with azimuth. You are supposed to adjust it so that when the counter weight is balanced and the anti-skating is at zero, the arm should be floating and be stationary.

I don't know much about the MKIII but the on-the-fly VTA, anti-skating, and tracking force adjustments are very handy. I miss that arm.
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.