Digital and Analog Versions
Owner’s Manual Revision E
ACU Firmware v1.16
RCU Firmware v1.16
XMOS Firmware v1.16
Page 1: ...Digital and Analog Versions Owner s Manual Revision E ACU Firmware v1 16 RCU Firmware v1 16 XMOS Firmware v1 16 ...
Page 2: ...TY INFORMATION 3 3 SAFETY MARKING SYMBOLS 3 4 SERVICE INFORMATION 3 5 M905 FEATURES 4 m905 Audio Control Unit Rear Panel 5 Audio Control Unit Front Panel 6 Remote Control Unit RCU 6 m905 Graphical User Interface 7 7 UNPACKING AND INSTALLING 8 Your m905 BoxWill Contain 8 Open and Inspect the Box 8 RegisterYour Unit 8 8 CONNECTING THE M905 8 Power Connections 8 Power Up Sequence 9 System Connections...
Page 3: ...ion temperature range 40 C to 70 C Maximum altitude 3000m 9843 ft Equipment suitable for continuous operation Weight ACU 7 8lbs RCU 2 2lbs 3 SafetyMarkingSymbols CAUTION READ ACCOMPANYING DOCUMENTS This symbol located on the equipment and in this manual refers to important instructions Read this manual thoroughly before operating this equipment WARNING ELECTRICAL SHOCK HAZARD This symbol located o...
Page 4: ...er SPL meter features include level peak fast and slow modes A C weighting Precision 5 dB step level control for speakers and headphones volume displayed in absolute or custom reference level Reference headphone amplifier circuitry with outputs on both the RCU and ACU Dedicated mono dim mute and sub mute switches Mono mode can be set to L R summed L only in both channels or R only in both channels...
Page 5: ...ignal 8 ADAT INPUT LIGHTPIPE connector provides a 2 chan nel input selectable in 4 pairs or 2 pair S MUX of an ADAT format digital source 9 USB Class 2 interface provides an asynchronous mode computer interface PCM up to 24bit 196kHz and DSD64 and DSD128 via DoP V1 1 Configured for two channels down from computer and 10 channels up to computer 10 Digital out provides a buffered digital loop throug...
Page 6: ...lease function illuminates solid and the push and hold function flashes 1 Graphical user interface GUI This color LCD displays all operating parameters and setup menus 2 Analog input unbalanced selects input source con nected to the unbalanced RCA analog input 3 Analog input balanced selects input source connected to the balanced XLR analog input 4 CUE input selects input source connected to the b...
Page 7: ...ER INTERFACE 1 2 3 4 5 1 6 6 1 Input buttons these 2 rows at the top and the bottom of the screen represent the available system inputs Each button directly corresponds to its particular input select switch and its corresponding input source Custom labeling is available via the setup menu Active input button is a friendly shade of blue 2 Main speaker level and speaker set this area shows the curre...
Page 8: ...our products but without your registration it s hard for us to help you if and when help becomes necessary So please take a few minutes to complete and send in the enclosed card or simply fill out the warranty registration form on our website We always keep your information private Thank you 8 Connectingthem905 Okay let s get started in making the necessary connections to get your m905 up and runn...
Page 9: ...ed for the left channel and the AES2 input is used for the right channel Note that AES Dual Wire mode requires moving a jumper on the m905 digital PCBA inside the unit See AES DW Setup in section 9 of this manual for details Use of a high quality 110 Ohm balanced cable is recommended S PDIF COAXIAL INPUT Standard coaxial stereo digital input The input impedance is 75 Ohms Use of a high quality 75 ...
Page 10: ... from a connected digital audio source However you may have your entire digital audio system referenced from a single master clock hence the ability for the m905 to receive and lock itself to this clock WORDCLOCK OUT The Word Clock output allows the user to synchronize other digital audio equipment to the m905 It functions in two modes When monitoring a digital input with the clock source set to w...
Page 11: ...the LCD display The m905 Analog has 4 dedicated input select buttons along the bottom of the LCD display Pressing any of these buttons will select the associated input source and connect it to the main monitor path The currently selected input source is indicated by the blue input icon on the LCD while inactive inputs are indicated by the gray input icons NOTE The displayed name is user configurab...
Page 12: ...otation of knob Decreases the volume in 0 5dB increments min level 0 Press Hold knob If the headphone level is 0 0 press and hold will recall the headphone preset level configured in SETUP If the headphone level is greater than 0 0 press and hold will mute the headphone output This state is indicated by the headphone mute icon on the display SPEAKER OUTPUT SELECTION The speaker output selection is...
Page 13: ...t or right is activated upon entering solo mode Toggles the left right channel solo mode if solo mode is already active SUB MUTE sub solo The multi function SUB MUTE sub solo button controls the sub mute and sub solo features NOTE These features are only available when the SUB DAC METER is configured for sub output mode in SETUP SUB MUTE mode mutes the signal going to the sub output if assigned Wh...
Page 14: ...ols the MONITOR TO CUE and the SPL PEAK CLEAR features of the system Normally the CUE output is sourced via the CUE input Engaging MON CUE routes selected control room monitor source to the CUE output When MON CUE is active this switch is lit solid green When mon cue is active this switch is lit solid green The type 2 SPL meter in the m905 RCU can hold the peak SPL measurement level configured in ...
Page 15: ...e sound pressure level based on the system configuration The current and peak SPL levels are displayed along with the filter mode in this section of the display The SPL measurement settings are configured in setup figure SPL meter SAVE RECALL OF USER CONFIGURATION After a 10 minute period of inactivity the m905 saves the current user configuration to non volatile memory Upon power up the m905 reca...
Page 16: ...ted output Continuous Volume UP DOWN LEFT Scroll left through inputs Scroll down through speakers RIGHT Scroll right through inputs Scroll up through speakers PLAY PAUSE Toggles MUTE of selected output Toggles SOLO mode MENU Toggles x feed Toggles L R control for inputs speakers LOGITECH HARMONY HUB IOS OR ANDROID SMARTPHONE CONTROL Using a Logitech Harmony WIFI to IR hub the m905 can also be cont...
Page 17: ... Important Note The m905 Analog ships with a standard ethernet cable for connecting the RCU This cable does not carry the headphone signal to the RCU so the headphone jack on the RCU will be deactivated and a small jack plug will be installed If you wish to use the headphone jack on the RCU you will need to buy the remote cable upgrade from your Grace Design Dealer or directly from the Grace Desig...
Page 18: ...members the last selected parameter in each setup mode and returns to that setting when each setup mode is entered In the following sections each of the controls and features of the setup mode will be detailed All system setup parameters are stored in non volatile memory At any point the setup mode can be exited with the following actions TO EXIT AND SAVE CHANGES Press and release the setup button...
Page 19: ...ked off the recovered digital audio clock When wordclock is selected the DAC is clocked off the wordclock input The USB input provides the clocksource options of internal wordclock ADAT and TOS S PDIF AES The clocksource for the USB input from either of the TOS S DIF AES options will be the last of those three previously selected So with the USB input selected select one of those 3 inputs TOS S DI...
Page 20: ...d demphasis auto meter output enabled ADAT 1 8 input name ADAT level offset 0dB clocksource ADAT s lock enabled demphasis off s mux off meter output enabled AES DW input name aes dw level offset 0dB clocksource aes dw s lock enabled demphasis auto meter output enabled S PDIF input name S PDIF level offset 0dB clocksource S PDIF s lock enabled demphasis auto meter output enabled AES1 input name AES...
Page 21: ...ut can have a programmed level offset to match each speaker system When a speaker output is selected this offset is added to the sub output level when the sub output is enabled The sub offset range is 20dB in 0 5dB steps PRESET LEVEL GLOBAL This parameter sets the speaker output preset level This parameter is the same for all speaker outputs Available range corresponds to the standard level displa...
Page 22: ... feature refer to the DIGI LOOP setup menu DIM SETUP From the setup screen pressing the dim button enters dim setup mode Once dim setup mode is active pressing the dim button will toggle the dim setting exactly as it does in normal mode The dim attenu ation level controls how much the speaker sub outputs attenuate when dim is active The available dim range is 35dB to 5dB in 0 5dB steps The default...
Page 23: ...vel is selected the output level is controlled by the meter level parameter below When follow speaker is selected the output level follows the speaker volume level including any input offset The default is fixed meter level METER LEVEL This controls the fixed output level of the meter output when meter output mode and fixed meter level are selected above The setting is equivalent to the overall sy...
Page 24: ...nside the m905 see m905 MAIN PCB Jumper Locations page 40 Disconnect the m905 from its AC power by unplugging the AC power cable Use a 2 Phillips screw driver to remove the top cover from the m905 There are 8 screws to remove on the top cover 4 on the top and 2 on each side Be careful to discharge any static electricity on the outside of the chassis before touching any of the jumpers inside the m9...
Page 25: ...he default is 20dB Nifty fact The Talkback output connector on the m905 comes configured such that it outputs the talkback signal only when the talkback switch has been pressed By moving J3 and J4 on the main pcb inside the m905 the Talkback output connector can continously output the signal from the external Talkback microphone amplifier This allows the user to utilize the external microphone inp...
Page 26: ...buttons Pressing MENU and CENTER also increments the Apple IR Remote ID for ap proximately 5 seconds The m905 will indicate that the remote is paired by displaying yes in this param eter field To unpair this a remote change this paramter to no The default is no In the event you do not want the m905 to respond to an Apple IR remote simply pair the remote to the m905 with your other devices turned o...
Page 27: ...B LOOP FORMAT When the loop source is ADAT or USB the digital audio format on the digi loop output can be configured Available options are consumer and professional The default is professional DIGITAL INPUT SETUP ADAT AES DUALWIRE This parameter controls the system configuration to use either the ADAT input or the AES DW input Available options are ADAT ACTIVE DEFAULT the adat input is configured ...
Page 28: ...The default is hold When decay is selected the peak will decay after the selected time When hold is selected the peak is held until the user clears it by pressing and holding the MON CUE spl clear button RESPONSE The response controls the ballistics of the SPL meter Available options are slow and fast The default is fast 12 AboutCrossfeed When listening to loudspeakers in a room your left ear hear...
Page 29: ...nse plot showing the response of the m905 cross feed circuit In this graph one channel of the headphone amplifier is driven The two traces show the direct channel and the op posite cross feed channel 55 5 50 45 40 35 30 25 20 15 10 5 0 dB 20 50k 50 100 200 500 1k 2k 5k 10k 20k Hz Direct Signal Crossfeed signal figure cross feed response graph 13 CommunicationErrorHandling If at any point communica...
Page 30: ...r USB UP CHANNEL SETUP In addition to playback the m905 s USB interface allows for up to 10 channels to be transmitted back to the computer These up channels allow the user to use the m905 as a simple I O computer interface Up channel operation is configured in the PC s USB Audio Driver Control Panel or Apple OSX Audio MIDI Setup Two modes are available The first option configures the device for 1...
Page 31: ...t is selected in the USB Audio Driver Control panel as shown Note If your application does not require more than 2 input channels the 2 input 2output setting is recom mended as it requires less over all bandwidth of the USB connection ...
Page 32: ... Wavelength Audio s website http www USBdacs com In the event that you have any setup issues which aren t addressed by these resources feel from to contact us directly at 303 443 7454 Monday through Friday 9 5 MST USING THE m905 FOR DAW PLAYBACK With the extremely high quality audio playback achieved with this USB interface the m905 can be great option as an stereo output device directly from your...
Page 33: ...wnload the m905 RCU firmware package from the Grace Design website and unzip it on your com puter Turn off the m905 and connect your computer via USB to the USB upgrader port on the m905 RCU Turn on the m905 The setup button will illuminate solid white on the remote control to indicate USB upgrader mode is active Note that the LCD display will be dark Once the m905 initializes it will ap pear on y...
Page 34: ...rom the RCU and then cycle the power to the m905 UPDATING ACU FIRMWARE TO UPDATE THE FIRMWARE ON THE m905 ACU PERFORM THE FOLLOWING STEPS Download the m905 firmware package from the Grace Design Website and unzip it on your computer Turn off the m905 and connect your computer via USB to the USB upgrader port on the m905 ACU Turn on the m905 The m905 will enter USB upgrader mode instead of communic...
Page 35: ...de process the folder will contain a file named ERROR TXT The type of problem encountered is reported on the Status line in ERROR TXT In this example a firmware file for the RCU was accidentally uploaded as indicated by the Incorrect file for this device error Disconnect the USB cable from the ACU and then cycle the power to the m905 UPDATING XMOS FIRMWARE TO UPDATE THE FIRMWARE ON THE M905 XMOS P...
Page 36: ... Firmware Upgrade to begin the XMOS firmware upgrade process The progress of the upgrade will be indicated in a pop up dialog box DO NOT DISCONNECT THE DEVICE OR INTERRUPT POWER TO THE m905 WHILE THIS IS IN PROCESS Once completed power cycle the system Should the firmware upgrade fail start the XMOS firmware upgrade process over again ...
Page 37: ...10Hz to 100kHz 19 degrees Crosstalk any channel 100Hz 104dB 1kHz 100dB 20kHz 79dB Balanced Input CMRR 60Hz 70dB 1kHz 70dB 10kHz 70dB Gain Range 104dB to 13dB Channel Tracking Accuracy Any channel 0 1dB Maximum Output Level 26dBu Maximum Input Level Balanced inputs 25dBu Unbalanced inputs 21dBu Impedances Balanced inputs 88k Ohms Unbalanced inputs 53k Ohms Balanced outputs 300 Ohms Minimum load imp...
Page 38: ...z 96kHz 1300Hz ADAT LIGHTPIPE 44 1kHz 50Hz 48kHz 70Hz 88 2kHz 50Hz 96kHz 70Hz s Lock Capture Range 44 1kHz 6Hz 48 kHz 7Hz 88 2 kHz 14Hz 96 kHz 20Hz 176 4 kHz 24Hz 192 kHz 30Hz Word Clock Superclock Input Impedance switchable 75 ohm 1Meg ohm 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 ...
Page 39: ...INPUT AMP BALANCED OUTPUT DRIVER OUTPUT DRIVER BALANCED MON TO CUE WORD CLOCK PLL LEVEL CONTROL LEVEL CONTROL LEVEL CONTROL AES3 1 THROUGH OUT AES3 OUT SPDIF OUT DIGITAL LOOP THROUGH USB2 DAC SUB METER BALANCED OUTPUT DRIVER LEVEL CONTROL DAC SUB METER OUT SPEAKER 3 MONO L R TALKBACK OUT X FEED DE EMPHASIS REMOTE CONTROL UNIT TALKBACK SELECT DAC SUB TALKBACK OUTPUT DRIVER BALANCED REMOTE CONTROL U...
Page 40: ...40 18 PCBJumperLocations MAIN PCB JUMPER LOCATIONS REAR PANEL DIGITAL I O PCB JUMPER LOCATION J7 AES DUAL WIRE ADAT SELECT ADAT AES 2 WIRE REAR PANEL ...
Page 41: ... specifications There are two options for loading moving coil cartridges 100 Ohms and 0 500 Ohm variable If you do not know the recommended load for your cartridge 100 Ohms is a good place to start If you know the recommended load then you can use the adjustable setting To adjust the cartridge loading to your specified value connect an Ohm meter to the Left channel RCA input jack on the rear panel...
Page 42: ...IN 1 RX PIN 2 GND PIN 3 TX PIN 4 5VDC PIN 5 GPIO PIN 6 TALKBACK PIN 7 HEADPHONE LEFT PIN 8 HEADPHONE GND PIN 9 RX PIN 10 TX PIN 11 6 5VDC PIN 12 3 3VDC PIN 13 TALKBACK PIN 14 GND PIN 15 HEADPHONE RIGHT presently unconnected provisional for RS422 operation 1 2 3 SHIELD HOT GROUND OPEN Unbalanced 1 4 Balanced Output XLR Balanced XLR output to unbalanced 1 4 input TALLY TALKBACK CONTROL GND 1 4 TRS P...
Page 43: ...umber Customers within the US are responsible for all inbound freight charges to Grace Design s facility while Grace Design will pay for return freight charges via ground service Customers outside the US must con tact their distributor for warranty product return details In order for Grace Design to provide efficient and timely warranty service it is important that you mail the completed warranty ...
Page 44: ...ed display window showing DSD input present 7 18 2013 edg C 4 5 34 added DSD128 references 7 18 2013 edg C 26 27 added USB up channel information 7 18 2013 edg D all added m905 Analog information 12 10 2014 edg D all added m905 IR remote information 12 10 2014 edg E all changed ACU RCU XMOS firmware Rev to 1 16 added phono input option info added digital speaker output info added dim and mute cont...
