Sony WM-D6C pro walkman

I bought my "Pro Walkman" back in the late 1980s as at that time I worked as a contract software engineer and often had to set up "home" in hotel or B&Bs. Often it was used with a set of Sennheisser headphones, but I also sometimes took a pair of Wharfedale Active Diamond speakers with me if I had a longer stay.

Due to the outstanding sound quality, I used it to listen to LPs and CDs which stayed at home while I was away, and also to make occasional live recordings or recordings from a radio tuner.

The leatherette outside cover makes it
more robust for daily use

As I recall, the walkman cost me the grand sum of £250 back in 1988 when I bought it. This represents over £600 (€800) in 2012 prices. This was an expensive piece of equipment to buy, but luckily, it worked well. It didn't take long to realise that the Walkman Pro could make more faithful recordings than my full-sized Yamaha cassette deck. Quite an achievement for such a small and densely packed piece of equipment running on batteries.

It's still in use

An adaptor for mono voice recordings with a vocal microphone. Both channels connected
together within the socket with a capacitor between them and the microphone to block
the "plug in power" DC offset from the walkman.

As befits a well made piece of equipment, it still works perfectly 24 years after it was built. I've used my walkman to transcribe old recordings onto the computer (the music behind this video, for instance) and also to make new recordings, such as the voiceover on this video. By using the walkman to do this, I could make the sound recordings in a room which didn't contain computers or their associated fan noise.

To make mono voice recordings, I use a vocal microphone and the adaptor pictured. There is a small signal to noise ratio gain of 3 dB possible with any stereo recording equipment if both channels are used to make identical copies of a mono signal and the result is added together on playback (these days, this step generally happens inside the computer).

Technicalities

The Pro Walkman never had a particularly long battery life because sound quality was optimized first. However, because modern NiMH cells have a much higher capacity than the NiCD cells that I used in it when it was new, the running time has actually improved markedly since it was new. Four cells at a time are loaded into a battery case. The resulting 6 V is a higher voltage than used for most modern electronics, but it wasn't enough at the time. For that reason, the circuitry includes a DC to DC converter to make a higher voltage for the electronics.

My walkman's serial number is 165912. Components have late 1988 date codes and my walkman has both the earlier phenolic printed circuit board and the earlier (better, long lasting) amorphous head.

The interior of the machine is packed with components, both electronic and mechanical. The large black rectangle in the centre of the photo is the motor, itself surprisingly large. Using Sony's "disc drive" principle, this drives the capstan at right angles. Speed accuracy and low wow and flutter are assured by quartz speed control of the transport. A lot of sophisticated features are packed into a small space.

More about it

Apart from offering excellent playback quality, the "Pro Walkman" also records and plays either with no noise reduction at all or with Dolby B or C noise reduction and can use Type 1, Type 2 and Type 4 cassettes. There's a control on the back which allows adjustment of playback speed for recordings which were made on a recorder which didn't run at the correct speed.

There are two inputs and two outputs on the device. You can record either from a microphone or from a line input. The microphone input provides power for an electret mic and a switch allows this input to be padded down by 20 dB for use in a loud environment. Recording levels from either input are set manually by referring to a slightly too simple five segment LED recording level meter which also functions as a battery level meter or can be switched off altogether for discreteness if a switch on the front is operated. Output is provided simultaneously to both line-out and a set of headphones and to line output. The volume control only affects the headphone output. All connectors are 3.5 mm jacks, which aren't really my favourite connector but it would be difficult to provide larger connectors for all these functions.