Sony Discman D-50

Sony Discman D-50
1982


The D-50 was the first portable compact disc player. Released only shortly after the compact disc system was introduced, it represented a major technical achievement, and was of course “the world’s smallest compact disc player” at launch.

Much folklore surrounds the development of the D-50. It is said, for example, that the design brief stated that the total size should be no bigger than three (or four, depending on who you believe) compact disc cases stacked on top of each other. If this was true, the designers certainly got close to this goal. It is also said that the D-50 was offered at a particularly economical price to help popularise the compact disc format. This may also be true, but though it was cheaper than the CDP-101 (Sony’s first domestic compact disc player), it was still pretty expensive, especially for something fragile that gets taken outside.

The complexity of the D-50 makes any attempt at a description of its inner working impractical, one could fill a whole website with the details of this one model alone. However, it should not go unrecorded that many special techniques and special components had to be employed to condense a functioning compact disc player into the small casing, which does not look excessively large even now. In particular, the special (and highly complex) integrated circuits needed to decode the digital data from the disc were not at this time available in formats intended for battery portables, so special alternatives had to be developed. At the time, the error correction chip of a compact disc player was the most complicated object to be found in the home.

The laser optics had to be miniaturised too, something that was done by folding the optical path. The system used was the “three beam” arrangement common in Japanese players. A few years later, Philips produced a very similar machine to the D-50 called the CD-100. This used Philips’s traditional “single beam” pickup, whose radial linear motor drew current continuously and thus resulted in the machine being very heavy on batteries.

Although the D-50 looks nice and small in our picture, there was a catch. As shown, there is no power source, so to use it as a portable one had to add one of the many different types of battery holders, cases or rechargeable packs that were offered. One of the most practical of these was the EPB-9C “battery case” which covered and protected the whole machine, whilst providing a holder for either 6 “C” size cells or one NP-11 rechargeable pack. This increased the size considerably, but also helped protect the fine polished finishes of the D-50 from scratches. It also provided a place to attach a shoulder strap, the only practical way to carry what was a rather heavy package.

The D-50 had no special devices to prevent skipping whilst being carried, so if one wanted an uninterrupted flow of music one had to be careful. Basic features such as track skip, search and pause were included, as was a time readout for the track in play, but there were none of the luxury features, such as A/B repeat and programmable replay, that the CDP-101 offered. It was realised that the D-50 may be the only compact disc player the user owned, so a proper line out connection was included for use with a hi-fi system or a tape recorder.

The D-50 remained in production for some years. Later on, a red version became available. The later versions can be easily identified as they have a green power switch. Early versions pre-dated the use of the word “Discman” and so are referred to by the rather awkward name “compact disc compact player”.

Categories: Discman