Dynacoustic SP500

The DYNACOUSTIC SP500 (also written SP 500) dynamic stereo headphones are manufactured in Japan. These are on-ear headphones where the pads press over the ears to make a sealed acoustic connection. Being a very early headphone, it has speaker type moving coil drivers with transparent cone. The bass response is very good, whilst the treble is average. Each cup has a dedicated volume control and wire going in. These would have been intended for use with amplifiers since the coiled wire is terminated with a ¼-inch stereo jack plug.

Review

These early headphones come from a time when the industry used miniature loudspeakers for the drivers. However, driver technology has improved greatly over the years with more powerful magnets, lighter coils and diaphragms, resulting in a wider frequency response. In the SP500, the 55 mm diameter drivers produce plenty of bass, and the treble is just slightly better than average. The sound is very reminiscent of the 70s era.

When I bought these headphones the volume control potentiometers made crackling noises and intermittent connections, however I was able squirt some electrical contact cleaner to rectify this issue. The ¼-inch jack was an annoyance as well, and I was tempted to replace it with a 3.5 mm jack so I could use it with my walkmans, however in the end I managed to find an adapter on eBay.

There is plenty of space inside the cups for modifications, and I was very tempted to upgrade the drivers and install modern woofers and tweeters. However in this case, they are valuable if kept unmodified. In the following pages of this multi-page article you can see what the driver and volume control potentiometer looks like.

Price/eBay

These headphones were very well designed and made with the usual Japanese high-quality engineering, and consequently there are many survivor models out there. People often buy these for sentimental reasons if they remember owning such a pair. A unit in good working condition might fetch a small packet on a good auction day, however on some days they can go for almost nothing.

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