WM-DD2DDII

WML ID #20

Manufacturer: Sony

Model: WM-DD2

Nick: DDII

Series: DD

Year: 1984

Made in: Japan

Initial price: 279 DM

Technical details, specifications

Battery: 2AA

Battery life: 9 h

Colors: black red gray

Dimensions: 79.7*110.*31.1 mm (273 cm³)3D size

Weight: 290 gr

Window: yes

Frame: plastic

Case: metal

Carry: pouch

Expandable: no

External compartment: no

Drive: DiscDrive

Tape selector: Manual switch

Waterproof: no

Speaker: no

Frequency range: 40-15000@4 Hz

FMax output: 2x20 mW

Functions

DC in: yes

Record by input: no

Record by int mic: no

Hotline mode: yes

Cue: no

Balance (L/R): no

Phone type: 1

Equalizer: no

Auto volume no

Auto reverse: no

Anti rolling: yes

AMS no

Blank skip no

Logic control: no

Hold lock: no

Noise reduction: Dolby B NR

Radio: no

Remote control: no

Wireless headphone: no

Indicator: led

Description

DD2 had the addition of Dolby B noise reduction, and many minor improvements.

The WM-DD2 appeared to be a WM-DD but with the addition of Dolby B NR. In marketing terms this is exactly what it was, though technically the change was far from trivial. The innovation that made this change possible was the introduction of miniature Dolby ICs that could run directly from the 3V battery supply without the need for a DC-DC converter (as had had to be employed in the WM-7, for example).
Even with these devices the changes made between the WM-DD and the WM-DD2 were far reaching and only possible because the printed circuit board was made with track work on both sides.
All the user saw, however, was that important extra switch. Dolby NR and the disc drive capstan servo had transformed the compact WM-2 into a serious hi-fi device.
The next step in the evolution of the Walkman was to add quartz crystal lock and Dolby C for playback to the DD series. This appeared in the next model, the WM-DC2.Via Walkman Central (edited)