When a product's webpage ends up as a Favorite on my browser, that's when I know I am screwed, and will probably end up buying said product. That's when I got interested, initially because the HPA3 is a USB-powered amp/DAC that utilizes a DAC chip made by a company you don't commonly see - Asahi Kasei's AK4390 chip, and I couldn't figure out what DAC the HPA4 was using.īut as I did my research, the HPA4 stood out for a bunch of reasons, and soon I realized I was obsessing about it all the time.

There hasn't been much buzz or hype about this model, and I didn't know much about it until recently. How did it come to this?'Įarlier this year, Fostex upgraded their little HPA3 DAC/amp with an new design, the HPA4. History of the HPA4, or 'The days have gone down in the West behind the hills into shadow. Foster has been around since the 1940s and is probably the biggest audio company you have never heard of. They are a subsidiary of the Japanese company Foster Electric (they merged with Foster in 2003). In addition to manufacturing their own products, they OEM for other brands (think Denon headphones, for example).

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