Sumiko Premier MMT Arm VTA?

Your arm does have VTA adjustment. There is a set screw on the right hand side, facing the turntable, of the arm, loosen it and the arm can be moved freely up or down. Tighten it and it will stay in place. What you are referring to is that Sumiko sold a base that allowed the VTA to be continuously adjusted, by turning a screw the arm would move up and down. This is a lot easier than releasing a screw and having the arm free to drop. To make it easier I use a deck of cards. If I need more height I add a few and then release the screw and bring the pivot point up to that height. If you need to lower the arm a bit, just remove some cards and loosen the screw.

Viridian, thanks for your response but I really think that there is not a VTA adjustment on my arm. I believe the arm I have is an early model and the VTA adjustment was built into subsiquent "improved"arms. There are no verticle adjustment set screws anywhere on the shaft base that is attached to the armboard. Is that the area that I should be looking? So now what? I mean it is perfect for this cart. The arm is perfectly parallel when on the record.But at some point I might want to get a different cartridge. All advice and thoughts would be welcome.Thanks

If it has no VTA adjustment, and you don't want to get another arm, then you have only one option, and that is to make machined spacers that will fit between the arm board and the base, that will be the correct thickness to raise the VTA to the proper level for that cartridge. This really allows only one VTA because it is too difficult to keep changing these for small variations in record thickness.
If the new cartridge has too much VTA, then you can use spacers that are available to fit between the cartridge and the headshell.

I suppose also you could use a spacer disc under the record mat,or different thicknesses of record mats to do the same thing as the headshell spacers, if the TT allows this.

Spindrifter, really weird; I have owned two of the arms and both were the same, with a set screw on the collar that attaches to the turntable base that the arm shaft fits into. You are in a pickle, but Tom made excellent suggestions. One alternative is that, as the arm takes a universal headshell, someone used to make one with a little hinge at the back that would allow you to cant it foreward or back. I don't think that it was the Orsonics, maybe Tom will weigh in again with the maker. It is an inelegant but simple solution.

Viridian is right, but the access to the set-screw adjustment is hidden unless you know where to look. Look at the outer rim of the MMT's mounting base, about 30 degrees counter-clockwise from the cue device indentation -- you'll find an unmarked HOLE. The adjustment can be accessed by an Allen (5/64, I think) wrench. Caution, the arm will drop as soon as you loosen the set-screw.
Best of luck,
Joe