Grace M902 Headphone Amplifier 2-Channel Grace M902

Grace M902 Headphone Amplifier 2-Channel Grace M902

Grace Design has been building audiophile quality products for the recording industry for over a decade. The technology developed for the m902, and all of our products, has evolved through a process of extensive listening, field testing and careful refinement. The m902 amplifier represents a combination of absolutely pristine audio performance, robust mechanical construction and bombproof reliability

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 (m902) are provided via RCA jacks on the rear panel for connection to stereo monitors.
• Balanced line level outputs (m902b) are provided via ¼” tip-ring-sleeve (TRS) 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.
• Infrared remote control for level control, left/right balance, mute and more when using the optional remote control unit.

Specifications:

• GAIN
  • Normal Mode: +0dB
  • Boost Mode: +10dB
• FREQUENCY RESPONSE
  • @ 0dBu out +/- .25dB: 22Hz - 120kHz
  • @ 0dBu out +/- .5dB: 12Hz - 260kHz
  • @ 0dBu out +/-3dB: 4Hz - 600kHz
• MAXIMUM OUTPUT LEVEL
  • @1kHz, 50 Ohm load: +21.4dBu (9.11Vrms)
• IMPEDANCE
  • INPUT: 53K Ohms balanced
  • INPUT: 53K Ohms unbalanced
  • OUTPUT: 1 Ohm
• DYNAMIC RANGE
  • @ 0dB gain: 116dB
  • @ -10dB gain: 119dB
• THD+N
  • +10dBu out, 50 Ohm load, SMPTE 4:1: <0.01%
  • Headphone +10dBu out, 50 Ohm load: <0.008%
  • Line Out +10dBu out: <0.02%
• ATTENUATOR CHANNEL MATCHING
  • Attenuator switch: <0.05dB
  • Attenuator range: 99.5dB
• D/A SPECIFICATIONS
  • Input sample rate: 32, 44.1, 48, 88.2, 96, 176.4, 192kHz
• THD+N
  • 44.1kHz, 24-bit, 1kHz, +20dBu out: <0.002%
• NOISE FLOOR
  • 0dB gain, 22-22kHz: -94dBu
  • 0dB gain, A-weighted: -97dBu
• POWER REQUIREMENTS
  • 115VAC: .16A
  • 230VAC: .08A