GRACE DESIGN m902 - Reference headphone amplifier / DAC

m902 key features :

• Stereo analog inputs - balanced (+4dbu) XLR and unbalanced (-10dbv) RCA.
• Ultra low distortion 24-bit /192khz DAC accepts stereo digital input sources in AES3, S/PDIF and TOSLINK (optical) formats with auto sample rate detection and digital de-emphasis filter.
• USB input provides a convenient way for users to enjoy a reference quality monitoring experience when connected to their computer. This interface supports 16-bit audio at 44.1 Or 48kHz sample rates.s-locktm dual stage PLL (phase lock loop) circuitry for the ultimate in low jitter digital signal stability and sonic integrity.
• Unbalanced line level outputs are provided via rca jacks on the rear panel for connection to stereo monitors.
• Front panel rotary encoder provides precision level control of both headphone and line output
• levels. Level adjustments are made in 0.5db steps within a 95db range.0.05db channel level matching to ensure true stereo balance at any monitoring level.
• A large, blue 7-segment display is used to show headphone and stereo main output levels.
• Calibration mode enables left/right balance adjustment for both headphone and mains outputs.
• There’s also a display dim mode that turns off all led’s except for the main power switch led
• X-feed (crossfeed) simulates the acoustics of a loudspeaker listening environment which can significantly improve imaging while reducing listening fatigue when using headphones. This feature employs carefully designed signal cross-feed, filtering and delay circuits to simulate hrtf (head related transfer functions).
• High current transimpedance output amplifier design drives 8 ohm loads. The m902 was specifically designed with low impedance headphones in mind.Only the highest quality 0.5% metal film resistors are used throughout and there are no electrolytic capacitors in the signal path. Sealed gold contact relays are used for all signal switching.

-- very good condition

-- original box