m904 / m904b - High Fidelity Stereo Monitor Controller / Remote Controlled (m904b)


 

While 5.1 surround has become well established in film and HD production, stereo is still king and remains the standard for producing and delivering music. Accordingly, we offer our monitor controller in stereo only versions - the m904 (and m904b).

The m904 combines all the same features and technology found in our flagship m906 surround controller, and is the perfect nerve center for any type of audio production facility - from project studio to world class mastering facility.

The m904 offers a full complement of balanced and unbalanced stereo analog and digital inputs, the latter featuring our latest generation reference 24bit/192kHz DAC technology with our proprietary s-Lock¢â PLL for rock solid digital stability (more info can be found in the technical discussion). All inputs and outputs are easily user calibrated for seamless integration into any playback environment with all types of playback equipment.

The m904 is configured as a 2U rack chassis, with all system controls built into the front panel, or is available as the m904b, with a blank 2U mainframe which is controlled by a separate remote control unit (m904RCU sold separately). Additionally, a standard m904 can be used with the m904RCU, so the user can select between local and remote control.

Included as a standard feature is our critically acclaimed reference headphone amplifier circuitry (as featured in our m902), with two output jacks on the mainframe or one jack on the m904b and one on the m904RCU. This circuitry provides absolutely pristine audiophile headphone amplification for critical monitoring, mixing and mastering.

While the m904 provides an unparalleled list of useful features, the real achievement for us was to implement all of this while maintaining our trademark musical, high fidelity audio performance. All components are selected and design decisions made for absolute audio transparency and long term reliability, making this the perfect link between your mix and monitors.

The m904 is here to empower audio professionals with the highest performance and most comprehensive feature set that any stereo monitor control system has to offer.

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  • multiple stereo analog inputs
  • 24bit/192kHz digital stereo inputs- AES3, S/PDIF, ADAT and TOSLINK
  • s-LockTM phase lock loop sample clock regeneration for ultra-low jitter and rock solid digital stability
  • precision speaker and headphone level controls with a 100dB range in 0.5dB steps
  • every electrical and mechanical design element maximized for absolute purist, audiophile performance
  • available as the m904b, which has a blank panel mainframe unit and is controlled via m904RCU (sold separately)
  • all I/O and audio are routed in the 2U rack mount mainframe powered by an internal AC supply
  • multiple speaker set selection - up to 3 stereo sets
  • m902 style high-current audiophile headphone amplifier built in with two outputs on front panel
  • complete system level calibration (inputs, outputs, inter-channel balance, dim)
  • balanced talkback microphone input and activation switch with additional external foot switch control jack
  • fixed level stereo DAC output for direct audio transfers
  • five year warranty on parts and labor

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ANALOG INPUT
THD+N @ 0dB gain, 1kHz
+20dBu out
<0.001% (0.00075% typical)
+10dBu out
<0.003% (0.001% typical)
0dBu out
<0.009% (0.005% typical)
Intermodulation Distortion SMTPE/DIN 4:1 50Hz, 7kHz
@+20dBu out
<0.002% (0.0015% typical)
@ 0dBu out
<0.008% (0.006% typical)
Frequency Response
+/-3dB
3Hz - 250Khz
Dynamic Range
20-22kHz bandwidth
112dB
20-22kHz bandwidth and A weighting filter
115dB
Output Noise
20-22kHz bandwidth, -20dB gain
High gain mode
-89dBu
Low gain mode
-98dBu
20-22kHz bandwidth and A weighting filter, -20dB gain
High gain mode
-91dBu
Low gain mode
-99dBu
Phase Deviation
20Hz to 20kHz
< 4
10Hz to 100kHz
< 15
Crosstalk any channel
100Hz
< 100dB
1kHz
< 100dB
20kHz
< 85dB
Balanced Input CMRR
60Hz
> 65dB
1kHz
>65dB
10kHz
>60dB
Gain Range
Low gain mode (0.5dB steps)
-105.5dB to +20dB
High gain mode (0.5dB steps)
-95.5dB to +30dB
Channel Tracking Accuracy
Any channel
+/-0.05dB
Maximum Output Level
Low gain mode (balanced)
+15dBu
High gain mode (balanced)
+27dBu
Maximum Input Level
Balanced inputs
+30dBu
Unbalanced inputs
+20dBu
Impedances
Balanced inputs
30k Ohms
Unbalanced inputs
50k Ohms
Balanced outputs
300 Ohms
Minimum load impedance
300 Ohms
DIGITAL TO ANALOG CONVERTER FIXED OUTPUTS
Output Levels
User selectable (0dBFS)
+16dBu / +24dBu
Fixed output trim range (0.5dB steps)
-95.5dB to +30dB
THD+N
1kHz, -1dBFS, 20-22kHz bandwidth (44.1kHz)
0.00%
Dynamic Range
20-22kHz bandwidth
>111dB
Input Lock Range
AES3/SPDIF
32kHz to 192kHz
TOSLINK
32kHz to 96kHz
ADAT LIGHTPIPE
30kHz 55kHz
S-Lock Sample Clock Intrinsic Jitter
20-22kHz bandwidth
<25ps
s-Lock¢â Sample Clock Jitter Rejection
1kHz sine jitter
-40dB
S-Lock Supported Sample Rates
AES3, SPDIF
44.1, 48, 88.2, 96, 176.4, 192kHz
TOSLINK
44.1, 48, 88.2, 96kHz
ADAT LIGHTPIPE
44.1, 48kHz
S-Lock Capture Range
44.1, 48kHz
+/- 10Hz
88.2, 96kHz
+/- 20Hz
176.4, 192kHz
+/- 40Hz
Word Clock / Superclock Input
Impedance (switchable)
75 Ohms / 1M Ohms
Minimum Voltage
3V peak to peak
Maximum Voltage
5V peak to peak
Word clock frequencies supported
44.1, 48, 88.2, 96, 176.4, 192kHz
Superclock frequencies supported
11.2896MHz, 12.288MHz (256x fs)
POWER SUPPLY / MECHANICAL SPECS
Power consumption
30W
Input Voltage 50-60Hz
100, 120, 220, 230-240VAC
Dimensions
Main chassis IEC 2U
3.5" x 10.5" x 17"
Remot control unit
1.6" x 8" x 5.25"
Weight
Main chassis
14.1lbs / 6.4kg
Remote control unit
2.3lbs / 1kg
All specifications are subject to change without notice

 

DOWNLOAD
* User Manual (PDF)