WA7 Fireflies Amp/DAC is a high performance headphone amplifier that was recently launched by New York-based Woo Audio, who equipped it with a USB Digital-to-Analog Converter and a vacuum tube headphone amplifier.
You shouldn’t be misled by the small size of the device: it is actually capable of excellent performance, being a reliable power house for state-of-the-art headphones. Each unit is priced at $799, and true audiophiles can tell you that the investment is totally worth it.