The M903 is a new improved headphone amp by Grace Design.

The m903 is a stereo reference headphone amp, Digital Audio Converter, and stereo monitor controller housed in a half rack space size. The m903 has been designed to provide audio pros in music, post and live-sound with fantastic headphone as well as stereo mains monitoring, whether from an analog or digital stereo source. It also serves the audiophile market as a reference quality Digital Audio Conversion and system preamp. The m903 provides balanced and unbalanced stereo analog inputs via rear panel XLR and RCA jacks. Both plus 4dBu and  minus10dBV analog sources are accommodated. A pair of front panel, parallel-wired 1/4" TRS outputs are included to allow two headphone pairs to be used simultaneously. The m903 also adds two pair of line outputs ( balanced and unbalanced ) on the rear panel, allowing the system to perform as a high-end monitor controller and system preamp. Each pair of line outputs may be level controlled separately. The m903 employs high current output amplifiers optimized for driving even the lowest impedance headphones. A front panel rotary encoder provides precision level control of both headphone and line output levels and level adjustments are made in 0.5 dB steps within a 95dB range. AES3, S/PDIF and optical digital sources are accepted via rear-panel XLR, RCA and TOSLINK connectors respectively. As an added convenience, a USB input is supplied for users who require a reference quality listening experience while connected to their computer. A front panel rotary switch selects between analog and digital sources, and a 4 LED array is provided to show valid digital source sample rates between 44.1 and 192kHz. A next generation, high performance 24-bit Digital Audio Converter or DAC, which includes Grace’s unique s-Lock TM dual stage PLL, (Phase Lock Loop) is utilized for conversion and provides stunning results with extremely low intrinsic jitter. Get yours today at the best possible price from RMC Audio Direct.