Rollin'

Today, the tape transport comes into the limelight. The first step was to check out the tape transport mechanism. Pushing the main cam to engage the transport didn't work - the response was very stiff. Either the transport was jammed or hard lubricants were keeping the joints gummed up. Everything was intact though and nothing was removed. The chances are more of lubricants gone bad, not a difficult problem. So far so good.





Inspection shows too much dust and dirt accumulated in all areas. Probing with a cotton swab, some areas also shown dust and lubricant mixed up into a gunk at certain spots. A close look at the tape path shows brown residue . The heads do not show too much wear though.

The transport needs to be completely taken apart for a thorough cleaning.


Dismantling the back shows the extent to which the lubrication had solidified. What was supposed to be a smooth flowing lubrication, had turned into a hard blob with a wax like consistency.

This area shows where the capstan/flywheel assembly is countered. A small nylon side screw is used as a thrust plate for a small bearing on the flywheel to rest. This is very important for the capstans to turn smoothly and correctly.


Nakamichi uses an interesting system of two capstans. This allows for the use of the capstans to provide tape tension across the playback head. Other makes rely on a single capstan, which exists to regulate tape speed. The Nakamichi system however, behaves like the dual capstan system in some professional reel to reel machines and ensures that the tape is pulled perfectly across the head.

Nakamichi's tape transport is simple and yet brilliant. The obvious problem of two capstans rotating at the same speed to regulate the speed of the same tape is avoided in simple but very effective manner. Both are of different diameters and run at slightly different speeds. Whilst a single motor powers both capstans, keeping them both locked in the same speed, they are belted at different flywheel diameters to ensure they turn at different speeds. At a time when other manufacturers were resorting to exotic schemes like PLL close-loop control to achieve 0.03% , Nakamichi met or bettered those specs using a simple belt driven system.

This is called Nakamichi Asymetrical Defused Resonance Transport. By making the two capstans rotate at different speed, any common noise is diffused. the red trace on the right shows the noise foot print of the transport compared even with other dual capstan transport. With a number of other features, this tape transport is one of the quietest, resulting in a very high-definition sound, for a cassette deck.


Now to further disassemble the transport for a thorough cleaning and reverse back the ravages of time.