Back in 2012, Jason Liao, CTO of OPPO Digital asked me to drop by. I had worked with OPPO as a supplier for a client on another project about seven years earlier. It is no news that OPPO makes exceptional disc players.
The plan was to start from scratch and explore and study every conceivable aspect (and some inconceivable aspects!) of making a better mousetrap. New tooling, new drivers, new quality levels of fit and finish with no limits. We discussed the time frame, and I got an answer that was a bit surprising: “when the product is absolutely ready, then we will be ready to ship.” This was quite different from other companies that must ship products by certain deadlines.
While I know at least a dozen speaker factories around the world that bang out ribbon tweeters, there are only a couple that can make ribbon planar headphones. With ribbon tweeters you can avoid buzzing by tensioning the diaphragm tightly or crimping, but for ribbon planar headphones these techniques are not ideal. Sensitivity is important if you want to develop a practical headphone that you can drive from your smartphone (perhaps 70 milliwatts per channel). To achieve this sensitivity most designers would end up with a lot of neo magnets – or a reasonable weight headphone with poor sensitivity. For the next two years, every convincible aspect of making the best possible headphone was studied, prototyped and mastered.
A review of the PM-1 and companion HA-1 Heapdhone Amplifier was published in audioXpress August 2014.