History of the Sony Walkman WM-D6C. Compiled from postings on Stereo2Go and tapeheads forums, as well as eBay listings of units for sale. February 1984: Original Sony Walkman WM-D6C released. Amorphous "pointy" parabolic PA259-3602A head marked "Japan", with screws on the side. Some say the earliest ones with parabolic head are the most desirable. Brown/green phenolic PC boards 1-611-494-11 with through-hole components. X-3305-830-1 Motor. Yellow indicators for Tape Type and Dolby NR Yellow Roman numerals for Tape Type; Only Sony logo on the leather case. Tape drive mechanism MT-D6C-20. January 1985: Generation 2: Supplement 1 notes Dolby chip change from CX20068 to CX 20218, as well as surrounding component value changes. PCB now -12. Serial # range undetermined. Mid 1986: Generation 3: Change from "pointy" parabolic to rounded head 35711 @ ~serial # 72000. Spring 1988: Change to Dolby sticker color from white (silver) to black ~ serial # 117,000. March 1994: Generation 4: Supplement 2 at ~ serial # 267,201 notes change to double-sided green glass epoxy PCB 1-651-545-11 with SMD components. Muting modules and EQ modules and DC-DC converter are part of the PCB, a lot less wires. Change to 1-541-851-11 motor. April 1996: Service Bulletin 395 issued. The motor was changed from X-3305-830-1 to X-3370-805-1. There are some component changes and the addition of a resistor and capacitor. April 1999: Supplement 3 shows two resistor values were changed to lower the headphones maximum output to make a French model. June 2001: Generation 5: Supplement 4 shows main PCB changed to 1-651-545-14; motor drive servo circuit redesigned with servo IC CX069A. The servo controller is now a smaller 8 pin IC and is protected which is switched by several other transistors and a MOSFET, to prevent damage. Comparator IC added. Change to Dolby IC #2002176. Rev. 1.1 service manual was issued. Generation 6: Change to permalloy head 35712 in serial #s ~514xxx and above. Marking "amorphous head" on the case is no longer present (date undetermined); however, only later units had the “amorphous head” script removed from the badge on the front of the machine so it cannot be used as a reliable guide to which type is fitted. 2002: WM-D6C production discontinued.
Not to my knowledge. The closest electrolytic is ECA-0JM221, 5mm diameter, 12mm height. This is an issue with the WM10/100 based models in general. With some work and slight offsetting I remember getting ECA-0JM221 to fit in at least the W800. This is one where you might want to try substituting with tantalum. Worth looking at SMD poly caps too, If I remember correctly a 4mmheight 6.3mm diameter 220uf existed at some point.
