Grace m903 - m903 Key Features; Frontpanel Controls and Features

page 4
m903 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, TOSLINK (optical) and USB for-
mats with auto sample rate detection and digital de-emphasis lter.
 s-lock
tm
dual stage PLL (phase lock loop) circuitry for the ultimate in low jitter clocking and sonic integrity.
• Two sets of line level outputs provided via RCA and ¼ TRS jacks for connection to stereo monitors.
• Front panel rotary encoder provides precision level control of both headphone and the 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.
• Large, white 7-segment display is used to show headphone and stereo main output levels.
• X-feed (crossfeed) simulates the acoustics of a loudspeaker listening environment which can signicantly improve imaging
while reducing listening fatigue when using headphones. This feature employs carefully designed signal cross-feed, ltering
and delay circuits to simulate hrtf (head related transfer functions).
• High current transimpedance output amplier design drives 8 ohm loads. The m903 was specically designed with low im-
pedance headphones in mind.
• Only the highest quality 0.5% metal lm 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.
• 5 Year transferable warranty on parts and labor.
m903 Frontpanel Controls / Features
 ILLUMINATED POWER SWITCH - illuminates green when unit is powered on.
 ROTARY INPUT SELECTOR SWITCH - selects between all available inputs.
 s-lock
tm
INDICATOR LED - illuminates when s-lock
tm
is active.
 SAMPLE RATE INDICATOR LEDS - auto sample rate detection from selected digital input source.
 CROSSFEED INDICATOR LED - crossfeed circuitry is user activated in setup menu or via the optional remote.
 OUTPUT LEVEL/EDIT ROTARY ENCODER - This stepped rotary encoder controls the selected output level in .5dB increments.
This encoder is also used to adjust other settings found in the setup menu.
 OUTPUT SELECTION LEDS – These LEDS indicate which output is currently selected by the user and under interface control.
 OUTPUT LEVEL / SETUP MENU DISPLAY - This blue, 2 digit display shows the current relative output level values based on the
position of the main level rotary encoder. The range of this display is 0 to 99. Note the decimal represents a 0.5dB increment.
This display is also used to give the user information in the setup menu.
 HEADPHONE OUTPUTS – Two stereo headphone output jacks wired in parallel.
FS
44
48
88
96
176
192
INPUT
Xfeed
OUTPUTS
s -Lock
AES
BAL
UNBAL
S/PDIF
TOS
USB
GRACE DESIGN, USA
VOLUME
push
reference headphone
amplifier / DAC
1
3
4
5
6
8
9
27