There is something about Micro Seiki’s engineering and aesthetics that have always resonated with me.
I guess everything started in the late 70s when I was in high school, making weekend trips to Tech HiFi, the local stereo shop. It was there that I had my first look at a Micro Seiki DDX-1000 and its three tonearms. I’ve been smitten ever since.
My early fascination with this turntable resurfaced on my 50th birthday when my wife found one on Craig’s List. It was in excellent shape with a beautiful MA-505 dynamic tonearm - and that’s when a second fascination started with the MA-505. This tonearm debuted in September 1976, 49 years ago and was fully adjustable while the record was playing: VTA, VTF, and anti-skate. Besides being a pretty arm, the engineering was extremely clever, to say the least.
Over the last few years, I’ve rebuilt and rewired a couple of these arms giving me a better understanding of their engineering sophistication - including the tungsten cable (not a wire) for the dynamic vertical tracking force adjustment. Using a low power microscope, the cable is actually comprised of about 24 tungsten micro strands.
At one point while I was restoring a dynamic VTA mechanism, it occured to me how interesting a dynamic azimuth control mechanism would be - given how difficult it is to properly calibrate that setting.
My initial thoughts were around how to re-design and re-engineer the pivot and the pivot position so the new geometry would accurately align with the stylus position in the record groove and how the stylus rotational axis needed to agree the rest of the tonearm assembly.
As I thought through possible design solutions, I knew that a gimbled bearing would probably not provide the longitudinal rotational functionality, and a unipivot totally lacked lateral stability . . . what I needed was an adjustable and completely stabilized unipivot bearing.
This is where the engineering puzzle started.