Member Reviews: Grace Design m903 reference headphone amplifier / DAC

What is it? The Grace Design m903 reference headphone amp / DAC is a device that is typically used in audio production / audiophile setups to take one audio source and give life to some other audio device. In my case I let it drive my HD-650 headphones with stock cable.   Here are a few things to note prior to reading any further. My headphones have been fully burned in for over 150 hours which is standard for Sennheiser products so the audio response from your setup may differ from mine.   What is inside the m903 anyway? Courtesy of Michael Grace DAC:  PCM1798 ( lower power usage, a tad more noisy than the 1792/1794 ) Current to Voltage:  THAT1570...

Great combo DAC/Amp, compact size, feature rich.

After researching the crowded and occasionally confusing world of headphone amps, I chose the Grace Design m903 because of the generally positive critical reponse that it has engendered. My listening tastes run to acoustic music such as Classical and Jazz so an amp that "colors" the sound of headphones would not be desirable. The Grace Designs m903 is the latest addition to the well regarded line of deluxe headphone amps/DACS that began with the m901 around a decade ago. An important positive feature offered by the m903 are its generous connectivity options, enabling the user to easily mix-and-match components. It has USB connectivity for connections to a computer, as well as the full...