Owner`s Manual Rev B
Contents
1. Do not interrupt the unit or disconnect the USB during this sequence The update process may take a few minutes Once completed the new firmware version will be displayed on the 7 segments At this time power cycle the m920 to return to normal operation Should an error occur during the update process an error code will be displayed instead of the firmware version All error codes start with If this happens restart the update process If the problem persists please contact our service department at 1 303 823 8100 x 105 page 19 Block Diagram LNdLNO SOTVNV Q3ONV IV8 O LNdLNO SOTVNV SLNdLNO 3NOHdQV3H SLNdLNO Wualaridiv LNdLNO 13 31 ANI Q39NV TIVS8 LAdLNO LAdNI Aldd S LAdNI 16 1 asa X 53 e B c 9ul 3NNVHO2 Z asa 74 Iq Q SAV LNd LNO 70JLNO9 13A31 HPlVGE Jv d D 3NI1G39NV1V8Nn INdino 0 2 J9 Se N 11 207 5 10 1 Re EP 4E SLANdNI TVLISIC 3ONV IV8 LAdNI 9O IVNV ko LNdNI Q39NV IV8 3NOHdQV3H AONVGsAdWISNVYL LAdNI 9O IVNV Q39NV IVaNn LNdNI GA9NV1IVENN TANNVHO 2 TOYNLNOD 13441 1 1 3NOHdQV3H SLNdNI 9O IVNV 20 ANALOG IN GAIN BALANCED I2. This feature allows the user to disable the infrared remote control operation of the m920 The m920 remote control uses command codes that are quite obscure but they are not proprietary Should inter ference occur from another manufacturer s remote control unit the remote control operation of the m920 can be turned off to prevent improper opera tion The default for this setting is on remote opera tion is enabled and the current status is preserved whenever the m920 is power cycled To change this setting e Push and hold the rotary encoder to enter the setup menu Now rotate the encoder until you reach the IR menu item Push and release the encoder to toggle on or off the infrared control which is indicated by the decimal points in the symbol illuminating on or extinguishing off e Rotate the encoder to navigate to other setup menu items or push and hold to exit the setup menu APPLE REMOTE PAIRING The Apple IR Remote provides a pairing feature that allows devices to only respond to specific remote controls To pair an Apple IR Remote press and hold the MENU and RIGHT buttons or the MENU and CENTER buttons Pressing MENU and CENTER also increments the Apple IR Remote ID for approxi mately 5 seconds The m920 will indicate that the remote is paired by displaying To view or modify the remote pairing status do the following page 11 e Push and hold the rotary encoder to enter the setup menu
3. phasis filter e User configurable DAC filter response for PCM and DSD playback e USB for playback of up to 384kHz 32 bit PCM as well as DSD64 and DSD128 playback via DoP e AES and S PDIF playback of up to 192kHZ 24bit PCM as well as DSD64 playback via DoP e New dual stage wide lock range PLL for im proved jitter rejection on non s locked sources Third generation s Lock dual stage PLL phase lock loop circuitry for the ultimate in low jitter clocking and sonic integrity e Two sets of line level outputs provided via RCA unbalanced and 1 4 TRS jacks balanced for con nection to stereo monitors e RCA line outputs can be configured for variable or fixed DAC output mode for operation as a page 3 4 standalone digital to analog converter 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 New X feed crossfeed simulates the acoustics of a loudspeaker listening environment which can significantly improve imaging while reduc ing listening fatigue when using headphones This feature employs carefully designed signal cross feed filtering and delay circuits to simulate HRTF head related transfer functions Hi
4. playback audio from it must have at least one avail able USB port The m920 ships with a standard USB type A to type B mini cable The type A connector plugs in to the computer and the type B mini con nector to the USB m920 input Operating the Head Both the headphone and the line outputs feature L2 is a round robin type where the line outputs are precision level control from the front panel rotary en controlled independently of each other More infor coder Each output can be completely independent mation on these two modes is found in the set up of the other in terms of level and balance control see menu section of this manual the setup menu section for further description of this The volume encoder is used to adjust the level of feature both the headphone and line level outputs inde The output selection indicator LED s show which pendently The level of the currently selected output output is currently under control by the volume con is displayed in the 7 segment display Turning the trol To toggle the output control selection simply encoder clockwise increases the output level and press and release the rotary level encoder You will counter clockwise decreases it see the selection indicator change Two different The m920 features an extremely high precision modes can be used for toggling through each output analog volume control Step size is 0 5dB and chan level The first L1 has the 2 line outputs ganged
5. Now rotate the encoder until you reach the rP menu item e When rP is displayed an Apple IR Remote is not paired default In this setting the m920 will respond to any Apple IR Remote or the m920 IR remote control Pressing the encoder button has no effect as only the Apple IR Remote can be used to enable pairing e When the decimal points in the r P Symbol are displayed an Apple IR Remote is paired In this setting the m920 will only respond to the paired Apple IR Remote or the m920 IR remote control Pressing the encoder button will unpair the Apple IR Remote and return the option to rP e Rotate the encoder to navigate to other setup menu items or push and hold to exit the setup menu DISPLAY DIMMER MODE The m920 features a bright user interface designed to give you clear operational information However situations may exist when you want to turn off this display while keeping your unit running This is pos sible with the display dimmer mode With the display dimmer enabled all the light on the front panel will extinguish after 4 seconds of inactivity Any change made by the user or system change sample rate or s Lock status will turn the displays back on for 4 sec onds then again extinguish Note the status of the display dimmer feature mode is retained whenever the m920 is power cycled To change this setting e Push and hold the rotary encoder to enter the setup menu Now rotate the encoder until you reach the dd menu
6. When you have reached the output you wish to adjust push the encoder again to enter the balance setting When no balance offset has been made both the left and right speaker symbols are shown in the 7 segment display page 10 e Turning the rotary encoder clockwise results in a balance adjust to the right This will be indicated by the right facing speaker symbol changing to the corresponding balance offset value Turning the rotary encoder counter clockwise results in a balance adjust to the left This will be indicated by the left facing speaker symbol changing to the corresponding balance offset value With each detent of the volume control the m920 alternates between adding 5dB to one channel and then subtracting 0 5dB from the other This continues until one channel is 3dB louder and the other is 3dB quieter To store your balance setting for the selected out put push and hold the encoder This will then send you out of the setup menu and back to the main level control screen The m920 stores all three balance level settings in non volatile memory and recalls these upon each power up POWER UP LEVEL This feature allows the user to save specific level settings for each output as the default power up level While default levels are set to 0 at the factory you may want to have the unit always power up at a specified level other than the default To program power up level settings e Push and hold the rotary en
7. item e Push release the encoder to toggle on indicated by the decimal points in the d d symbol turned on or off e Rotate the encoder to navigate to other setup menu items or push and hold to exit the setup menu LEVEL OFFSET ADJUST With three independently controlled analog out puts headphones line 1 and line 2 the m920 is designed to function as a high performance monitor page 12 controller for the professional studio or any type of playback scenario To enhance its flexibility in inte grating into any playback setup each output level can be offset by 9 5 dB in 5 dB steps This allows matching of loudspeaker sensitivities for constant volume when switching between speaker systems To adjust each output level offset setting e Push and hold the rotary encoder to enter the setup menu Then rotate the encoder until you reach the 3 level offset menu items labeled oH headphones o1 line 1 and o2 line 2 e Once you are at the outputs who s level offset you wish to change push and release the encoder to enter the offset level readout e Rotate the encoder clockwise to increase the offset 0 to 9 or counterclockwise 0 to 9 to decrease offset Note the decimal point indicates the 5 dB stop between numbers e you have set your level offset push and release the encoder to store the setting and return to the setup menu or push and hold the encoder to exit the setup menu CROSSFEE
8. reset to OFF whenever the m920 is power cycled To activate this feature Push hold the encoder to enter the setup menu Now rotate the encoder until you reach the output toggle lock mode indicated by the OL symbol in the 7 segment display e Pushing the encoder once turns the this mode ON which is indicated by the decimal points illuminating in the 0 1 symbol Turning the rotary encoder counter clockwise turns this mode OFF which is indicated by the OL symbol without the decimal points SELECTING USB CLASS 1 OR USB CLASS 2 This setting determines the whether the m920 func tions as a USB class 1 or class 2 audio device USB class 1 audio mode supports playback of audio files with sample rates up to 96kHz For playback of files above 96kHz you will only need to use the setting for USB class 2 Audio For complete details on how to configure your computer for playback over USB please refer to the computer setup chapter of this manual To change this setting e Push and hold the rotary encoder to enter the setup menu Now rotate the encoder until you reach the USB dass select menu item indicated by either the U1 or the U2 symbol in the 7 segment display e Push and release the encoder to toggle between and select either mode U1 indicates class 1 USB operation while U2 indicates class 2 USB operation e Push and hold the encoder to store the setting and exit the setup menu INFRARED REMOTE CONTROL ENABLE
9. setup menu or push and hold the encoder to exit the setup menu page 13 FILTER DSD DIGITAL FILTER RESPONSE The m920 provides the user with the ability to change the bandwidth of the digital filter used by the DAC when monitoring DSD sources To adjust DSD digital filter response setting e Push and hold the rotary encoder to enter the setup menu Then rotate the encoder until you reach the Filter DSD screen as indicated by the Fd symbol e Push and release the encoder to enter the DSD filter readout e Rotate the encoder clockwise to increase the filter bandwidth and rotate the encoder counter clockwise to decrease the filter bandwidth Available options are 47kHz 50kHz 60kHz and 70kHz e you have set the desired DSD filter response push and release the encoder to store the setting and return to the setup menu or push and hold the encoder to exit the setup menu LINE OUTPUT MODE The rotary encoder is used to select and adjust the volume of the three available sets of outputs head phones line 1 and line 2 Depending of the output mode selected here the two line outputs can either be selected and controlled independently of each other or they can be grouped together and con trolled in parallel These options depend on how your m920 is installed you may want to send the identical parallel line outputs to two different input destinations power amp powered monitors head phone distribution etc Or yo
10. to nel matching is within 0 05dB for all settings Also gether and they are controlled in unison the second embedded within the volume control architecture is page 8 3 stage acceleration curve The encoder has 24 po sitions Turning it one revolution slowly will result in a change of 12dB 24 x 0 5dB As the rotation speed increases each step goes from 0 5dB to 2 0dB and then to 4 0dB This allows not only precise control but also convenience when large volume changes are desired Any changes made are reflected in the 7 segment display Level range is from 0 0 to 99 5 NOTE The least significant digit s decimal point is used to indicate 0 5dB increments The improved s Lock is our proprietary PLL Phase Lock Loop circuitry that has been specifically devel oped for the m920 and its big brother the m905 When using the TOSLINK S PDIF or AES3 digital inputs the digital audio stream contains an embed ded clock that can contain various forms of jitter The s Lock PLL will lock to this clock source and provide an extremely stable and ultra low jitter clock to run the DACs s Lock is a crystal based PLL used for regenerating the incoming digital clock The crystals used have ex tremely low intrinsic jitter and are capable of locking to sample rates of up to 192kHz When the digital in put selected for the DAC is active the s Lock circuitry automatically captures the incoming recovered clock fr
11. 3 available outputs phones line 1 and line 2 The newly selected output indicator LED will illumi nate and its corresponding level will be displayed on the 7 segment display Pressing this button while in the m920 setup menu functions the same as pressing and releasing the encoder serving as the enter switch RIGHT BALANCE MODE MONO Pushing this but ton will directly enter balance mode option From here pushing the up button will adjust the left vol down and right vol up balance Conversely push ing the down button will adjust the right vol down and left vol up balance These changes are indicated by the right or left facing speaker symbol changing to the corresponding balance offset value Please refer back to the previous chapter accessing and us ing the setup menu for a more detailed description of adjusting the balance setting Pushing and holding the RIGHT button during nor mal operation will toggle the MONO mode feature of the m920 This setting simply sums the left and right channels of all outputs together When MONO mode is active the 7 segment display no longer displays the current output level numbers and shows two large facing brackets Pushing and holding again returns the m920 to normal stereo operation as in unmute the output NOTE Pushing and holding the dicated by the brackets changing back to the current UP DOWN buttons results in continuous volume output level numbers changes The lon
12. D MODE X FEED Please refer to the detailed description of this fea ture earlier in this manual Crossfeed is only applied to the headphone outputs This feature is toggled on and off in the setup menu and its current status is preserved whenever the m920 is power cycled To activate e Push and hold the rotary encoder to enter the setup menu Then rotate the encoder until you reach the crossfeed mode screen as indicated by the letters CF e Push and release the encoder to activate crossfeed which will be indicated by the illuminated the decimal points C F e you have activated or deactivated crossfeed either rotate the encoder to advance to the next setup menu item or push and hold the encoder to exit the setup menu MONO MODE This feature sums the left and right channels on every set of outputs This can be quite useful for checking for phase and balance issues in mixing and mastering To activate mono mode e Push and hold the rotary encoder to enter the setup menu Then rotate the encoder until you reach the mono mode screen as indicated by the 1 symbol release the encoder to activate mono which will be indicated by the illuminated decimal points e Once you have activated or deactivated mono mode either rotate the encoder to advance to the next setup menu item or push and hold the encoder to exit the setup menu S LOCK ENABLE In certain cases the incoming samp
13. EE bp 4 parvo Piste x ILNW phones line 1 and line 2 The newly selected output indicator LED will illuminate and its corresponding level will be displayed on the 7 segment display Pushing and holding this button enters the m920 setup menu From here you can control the setup menu in the same way as from the front panel volume encoder only with the volume up volume down buttons used to scroll and a single push of the OUTPUT button serving as the enter switch Please refer back to the previous chapter accessing and us ing the setup menu for detailed information on how to navigate the setup menu BALANCE MONO Pushing this button will directly enter balance mode option From here pushing the volume up button will adjust the left vol down and right vol up balance Conversely pushing the volume down button will adjust the right vol down and left vol up balance These changes are indicated by the right or left facing speaker symbol changing to the corresponding balance offset value Please refer back to the previous chapter accessing and us ing the setup menu for a more detailed description of adjusting the balance setting Pushing and holding the balance button dur ing normal operation will toggle the MONO mode feature of the m920 This setting simply sums the left and right channels of all outputs together When MONO mode is active the 7 segment display no longer displays the current output level nu
14. F inputs support PCM audio data with sample rates from 44 1kHz to 192kHz 24 bit as well as DSD64 via DoP The TOSLINK input supports PCM audio data with sample rates 44 1kHz to 96kHz 24bit The USB input supports PCM audio data with sample rates from 44 1kHz to 384kHz 32bit in addi tion to DSD64 and DSD128 via DOP page 7 ASYNCHRONOUS AUDIO m920 s asynchronous mode USB DAC supports The asynchronous mode USB converter in the m920 standard driverless operation on MAC to 384kHz represents a significant improvement over any previ PC to 96kHz For sampling rates above 96kHz PC ous type of USB DAC Previously a USB DAC worked users will need to download and install a free driver under standard adaptive mode USB audio which on their computer This driver can be found on our means the DAC s clock would have to sync to the website http www gracedesign com support sup non audio related computer USB buss master clock port htm As you can imagine the computer has a lot else to Driverless operation basically means plug and do so the incoming clock signal to which the DAC s play The m920 will automatically show up in your clock would have to sync was not ideal and would computer s list of supported audio devices as Grace result in unwanted jitter Audio Device In most cases simply choose that as With asynchronous mode USB the USB DAC be your audio playback device and the system will work comes the master to which the
15. NPUT OdB 0 5dB 8 0dB Headphone output volume at maximum Balanced Line output volume at maximum Unbalanced Line output volume at maximum FREQUENCY RESPONSE UNBALANCED IN UNBALANCED OUT 15Hz 50kHz 9 5Hz 72kHz 4Hz 192kHz OdBu out 25dB OdBu out 5dB Frequency Response Unbalanced In Unbalanced Out MAXIMUM INPUT LEVEL 22dBu 16dBu Balanced Input Unbalanced Input MAXIMUM OUTPUT LEVEL 22dBu 23dBu 20dBu Unbalanced output 1kHz 100k Ohm load Balanced output 1kHz 100k Ohm load Headphone output 1kHz 50 Ohm load IMPEDANCE 106K Ohms 53K Ohms 95 Ohms 47 5 Ohms 1 2 Ohm Balanced Input Unbalanced Input Balanced Output Unbalanced Output Headphone Output DYNAMIC RANGE 116dB 117dB OdB gain Balanced In gt Balanced Out OdB gain Balanced In gt Headphone Out BALANCED INPUT 0 008906 0 005090 lt 0 00045 lt 0 00075 Gain Headphone Out 10dBu 50 Ohm load Unbalanced Line Out 10dBu 100k Ohm load Balanced Line Out 20dBu 100k Ohm load ATTENUATOR lt 0 05dB 97 5dB Channel matching Attenuator Range OUTPUT NOISE FLOOR BALANCED INPUT Balanced Output volume at maximum 22 22kHz Balanced Output volume at minimum 22 22kHz Unbalanced Output volume at maximum 22 22kHz Unbalanced Output volume at maximum 22 22kHz VOLUME SETTINGS FOR UNITY GAIN 93dBu 99dBu 103dBu 105dBu balanced gt balanced out un
16. balanced in gt balanced out balanced gt unbalanced out unbalanced in gt unbalanced out co UJ 99 with Offset 8 D A CONVERTER Input Formats AES S PDIF TOSLINK PCM kHz 44 1 48 88 2 96 176 4 192 05064 Input Formats USB PCM kHz 44 1 48 88 2 96 176 4 192 352 4 384 D5D64 050128 Input Sample Rate 32 44 1 48 88 2 96 176 4 192kHz THD N 44 1kHz 24bit 1kHz 1dBFS Unbalanced Out 15dBu 44 1kHz 24bit 1kHz 1dBFS Balanced Out 15dBu lt 0 0005 lt 0 0005 OUTPUT LEVEL Unbalanced Output OdBFS Volume at maximum trim at 0 Balanced Output OdBFS Volume at maximum trim at 0 Unbalanced Output OdBFS Fixed DAC Output Mode 9dBu 17 6dBu 8 2dBu POWER REQUIREMENTS 120VAC 230VAC 0 16A 0 08A DIMENSIONS AND WEIGHT Dimensions H1 7 xW8 5 x D8 25 Weight 5 bs 2 2kg page 21 Your m920 chassis is constructed out of high quality stainless steel Under normal circumstances virtually no maintenance is required to keep the unit looking shiny and new However if your unit becomes smudged or dirty here are some cleaning tips We recommend using either Pledge furniture polish or Zep brand stainless steel cleaner available at the hardware store Apply cleaner to a clean dry lint free cloth and gently wipe all stainless surfaces taking care not to allow the cleaning product to build up around the panel switches or knobs page 22 1 Grace Design warrants all
17. box which contains the m920 unit an AC power cord a USB cable a small plastic bag containing four hand threaded machined metal feet and a warranty registration card OPEN AND INSPECT THE BOX Open all shipping boxes carefully remove the m920 and put it aside Before you go any further check to make sure the above listed components are included with your shipment If you believe something is missing contact your Grace Design dealer and they will make sure you re taken care of SAVE YOUR BOX We strongly encourage you to save the box and shipping materials supplied with your m920 They are specially designed to properly protect these valuable components and in the unlikely event that you need to return them for service only these OEM shipping materials can ensure their safe return to our factory REGISTER YOUR UNIT We strongly urge you to register your unit with Grace Design We provide a limited 5 year trans ferable warranty on all of our products but if you register your system it s easier for us to help you if necessary So please take a few minutes to complete the enclosed warranty registration card and mail it in or you can simply go to the warranty registration form on our web site We do not share your informa tion with anyone Thank you INSTALLING THE FEET The m920 is designed to either be placed on a flat stable surface in your studio or listening environ ment or be rack mounted If you don t plan to rack m
18. cm U8 LE UD lt m920 High Resolution Monitoring System Owner s Manual Rev B all contents Grace Design Lunatec LLC www gracedesign com 303 823 8100 Thanks for purchasing the Grace Design m920 high resolution monitoring system The m920 represents a powerful combination of pristine audio performance ro re bust mechanical construction and steadfast liability While we strive to build all our products to be simple to setup and intuitive to operate we do sug gest that you spend a little time familiarizing yourself with the features and operational functions outlined in this manual Doing this will make your experience with the m920 more productive and enjoyable n the event that you encounter any technical or operational difficulties with this or any Grace Design product please feel free to contact us at 303 823 8100 Our office hours are from 9 to 5 Monday high resolution 12 niteiririd system HP U1 le 920 xfeed 5 through Friday MST Or you email questions to info gracedesign com Also please remember to visit our website www gracedesign com for the latest Grace Design prod uct information owner s manuals and technical documents Grace Design has been building superlative quality professional audio products since 1995 The technol ogy developed for the m920 has evolved through a process of extensive listening test
19. coder to enter the setup menu Now rotate the encoder until you reach the power up level settings which are indicated as PH for headphones P1 for line output 1 and P2 for line output e When the m920 is in L1 mode both line outputs ganged together for volume control the preset level for the unbalanced line out L1 will be used for both sets of outputs e When you have reached the output that for which you d like to enter the power up level push the encoder again to display the current power up level e From here you can rotate the encoder to adjust the power up level e From here you can either push and hold to immediately store the level which will then send you back to the main level control screen Or push the encoder once without holding to exit back to the first level of the setup menu from where you can select and adjust another power up level Note This option does not store the power up level until you push hold and exit back to the main level control screen OUTPUT TOGGLE LOCK OUT MODE Situations may exist when you need to lock the output level select toggle function of the encoder to prevent inadvertent switching This mode is reset to OFF whenever the m920 is power cycled Once this mode is enabled pressing and releas ing the encoder button no longer toggles the m920 through the 3 available outputs Pressing and hold ing the encoder button will still allow the user to enter the setup menu This mode is
20. computer s USB Different operating systems and audio players will buss gets synced So the computer is now synced pose their own set of complications in setting up to a crystal based audio clock signal and the system the m920 as the audio playback device In the event works with dramatically lower jitter No phase lock that plug and play operation does not occur you loop or sample rate conversion is necessary which will need to look at some specific setup variables for means bit perfect playback from a computer with your player and OS In this case we will direct you to zero interface induced jitter In addition the USB a very well written and comprehensive document by port ground is completely isolated from the m920 our friend and colleague Charles Hanson from Ayre audio ground This eliminates the possibility of noisy Acoustics http www ayre com usb htm computer grounds inducing any noise or impurity in This is an invaluable resource for computer USB the m920 audio circuits audio setup information for most current operat ing systems and we strongly urge you to familiarize yourself with the information pertaining to your spe cific OS In the event that you have any setup issues which aren t addressed by these resources feel from to contact us directly at 303 823 8100 M Friday 9 5 MST or you can email our service department service gracedesign com COMPUTER AUDIO REQUIREMENTS Regardless of the type of computer you will use to
21. d a 6ft 1 8 meter maximum length for this cable STEREO HEADPHONE OUTPUTS Headphone outputs are provided via two TRS Tip Ring Sleeve jacks These outputs are wired in parallel Connection to headphones should be made using standard 4 TRS stereo connectors UNBALANCED LINE OUTPUTS A stereo pair of unbal anced line level outputs are provided via two RCA jacks These outputs should be connected to pow ered speakers a preamplifier or power amplifiers using standard unbalanced RCA cables BALANCED LINE OUTPUTS A stereo pair of balanced line level outputs are provided via two TRS jacks These outputs should be connected to powered speakers a preamplifier or power amplifiers using standard balanced cables Connection to an unbal anced input is also possible See diagrams below for proper termination Balanced Output 1 4 TRS Balanced Input XLR The m920 allows for selection from a variety of analog and digital input sources The rotary input selector switch is used to choose the input source for both the headphone amplifier and line outputs ANALOG INPUTS The m920 provides both balanced and unbalanced stereo inputs To select either of these analog inputs rotate the input selector to the desired input When an analog input is selected the m920 s internal DAC is turned off DIGITAL INPUTS The m920 provides the following digital input sources AES3 S PDIF TOSLINK and USB The AES3 and S PDI
22. ds Once the m920 has entered the setup menu you will see the 7 segment display change to reflect the cur rently activated setup menu item To navigate through the available setup menu items simply rotate the encoder knob which will scroll you through the available menu items either clockwise or counter clockwise Once the last item is reached continuing to rotate will loop you back to the first To exit the setup menu at any time press and hold the encoder knob for 3 seconds The 7 segment display will switch back to the current output level once the setup menu has been exited Note When the setup menu is exited the last mode you were in will be the first mode activated the next time you enter the setup menu This allows quick access to the parameter you are currently adjusting The setup menu is also accessible by the optional m920 infrared remote control Please refer to the Remote Control Operation chapter for a detailed description of how this works Following is each available setup menu option in the sequence they appear BALANCE MODE This provides individual left right balance control of 6dB in 0 5dB increments for each available output headphone Line 1 and Line 2 To program balance settings e Push and hold the rotary encoder to enter the setup menu then rotate the encoder until you reach the balance settings which are indicated as bH for headphones b1 for line output 1 and b2 for line output e
23. e Class Equipment grounded type e Electrical rating 100 120 220 240V 50 60Hz 25W e Mains supply voltage fluctuations are not to exceed 10 of the nominal supply voltage e Pollution Degree 2 e Installation Over voltage Category Il for tran sient overvoltages e Maximum Relative Humidity 8096 e Operation temperature range 10 to 40 C Storage and transportation temperature range 40 C to 70 C e Maximum altitude 3000m 9843 ft Equipment suitable for continuous operation e Weight 2 3kg 5165 Safety Marking Symbols ommmssce CAUTION READ ACCOMPANYING DOCUMENTS This symbol located on the equip ment and in this manual refers to important instructions Read this manual thoroughly before operating this equipment WARNING ELECTRICAL SHOCK HAZARD This symbol located on the equipment and in this manual indicates the poten tial for electrical shock hazard SERVICE INFORMATION The Grace Design m920 contains no user service able components Contact Grace Design for repair and upgrade information In the event that your Grace Design m920 needs to be returned to the fac tory contact us for a return authorization number Stereo analog inputs balanced 4dBu XLR and unbalanced 10dBv RCA e Ultra low distortion 32 bit 384khz Sabre DAC accepts stereo digital input sources in AES3 S PDIF TOSLINK optical and USB formats with auto sample rate detection and digital de em
24. e plug in the device you want to upgrade If this happens disconnect the m920 from the PC power cycle the m920 and retry page 18 XX XMOS USB Audio 2 0 ST Firmware Upgrade No device found Please plug in the device you want to upgrade 3 Once properly connected click the browse button to navigate to and select the m920 firmware file The Upgrade window will now indicate that the system is ready for firmware update X XMOS USB Audio 2 0 ST Firmware Upgrade Grace Design m920 USB Audio 2 0 0x20B 1 0x300D 0 02 1492 168 0 35 engineering products m920 firmware XMOS Ibin m920 DFU 2 Device opened Ready for firmware update 4 Click the start button to commence the firmware update The update status is indicated below the Upgrade window XX XMOS USB Audio 2 0 ST Firmware Upgrade Upgrade Ready for firmware update Entering upgrade mode Upgrading firmware Starting firmware The Upgrade window will display Firmware upgrade finished successfully once the update process is complete If this message does not appear or the upgrade fails start the update process over Once the upgrade is successful click Exit to close the application With the PC still powered on and the m920 still connected via USB to the PC turn the m920 off and then back on Upon powering back up the m920 will display UF on the 7 segment display to indicate that it is Updating Firmware
25. ger a button is held the quicker the UP DOWN VOLUME UP AND DOWN MENU NAV In volume level changes normal operation pressing the up or down buttons If the setup menu is active the UP and DOWN but will change the selected m920 output level respec tons are used to scroll through the available setup tively in 0 5dB steps Also pressing the UP or DOWN menu items and parameters just like rotating the buttons while the selected output is muted will encoder knob on the m920 When the m920 is functioning as a standalone dig in the setup menu The headphone and balanced ital to analog converter the unbalanced line output line output L2 will function normally ofthe L1 can be configured as a fixed DAC output To configure the m920 for fixed DAC operations do In this configuration the selected DAC source is the following output on the L1 connector without passing through 1 Unplug the AC power cord from the rear of the the attenuator circuitry This provides the purest pug signal path for the most critical DAC applications and nos prevents accidental changes in volume balance etc 2 Witha 2 Phillips screw driver remove the 8 Caution should be taken when using this operating mounting screws from the top cover mode as full amplitude signals will be present on 3 Remove the lid and find the Fixed DAC Output the L1 output jumpers J10 J11 and J12 When configured for fixed DAC output mode the m920 will disable the volume control selec
26. gh current transimpedance output amplifier design drives 8 ohm loads m920 was specifi cally designed with low impedance headphones in mind Only the highest quality 0 596 metal film resistors are used throughout and there are no electro lytic 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 Apple IR remote control is supported with op tional pairing USB firmware upgradability 5 Year transferable warranty on parts and labor s Features high resolution na S PDIF monitoring system si dio x TOS 4 USB 440 L BAL PHONES gt 9 es INPUT UNBAL GRACE DESIGN 104 9 8 7 6 50 463 2 1 7 OUTPUT SELECTION LEDS These LEDS indicate ILLUMINATED POWER SWITCH illuminates white which output is currently selected for volume when unit is powered on control ROTARY INPUT SELECTOR SWITCH selects be 8 CROSSFEEDINDICATORLED Crossfeed circuitry is tween all available inputs user activated in the setup menu or via optional S LOCK INDICATOR LED illuminates when s wireless remote control Lock is active 9 OUTPUT LEVEL SETUP MENU DISPLAY This white SAMPLE RATE INDICATOR LEDS auto sample rate 2 digit display shows the current relative output detection from selected digital input source level val
27. ing and careful re finement Regardless of what type of monitoring you do your m920 will faithfully serve as an invisible link between your source audio and your headphones or speaker systems We sincerely hope it helps you achieve a new level of excellence in your work 7 S PDIF 1 sLock NT 4x e E TOS ex USB BAL 4 UNBAL SIGN INP GRACE DE L CONTENTS Welcome 2 About s lock 9 Important Safety Information 3 About x Feed crossfeed 9 Safety Marking Symbols 3 Accessing And Using The Setup Menu 10 m920 Key Features 3 Grace Design IR Remote Control Operation m920 Front Panel Controls Features 4 Apple IR Remote Control Operation 16 m920 Rear Panel 5 Fixed DAC Output Configuration 2 Unpacking Installing your m920 5 Updating Firmware 18 Powering up the m920 6 Block Diagram 20 Input Connections 6 Specifications 21 Output Connections Cleaning and Maintenance 22 Selecting Input Source Z Warranty Information 2 m920 USB Computer Audio Configuration 8 Manual Revisions 23 8 page 2 Operating the Headphone and Line Outputs lt Important Safety Information 222220 2 GENERAL e Indoor use only Ordinary Protection This equipment should not be exposed to dripping or splashing e Avoid placing objects filled with liquids such as vases or glasses on this equipment
28. le rate of a AES3 S PDIF or TOSLINK input signal may be on the thresh old of the s Lock lock range In this scenario the unit may go in and out of s Lock The s Lock Enable fea ture allows the s Lock PLL to be turned off for these situations To enable or disable the s Lock PLL e Push and hold the rotary encoder to enter the setup menu Then rotate the encoder until you reach the s Lock Disable screen as indicated by the sL symbol Push and release the encoder to toggle the s Lock enable status Illuminated decimal points in the 5 1 Symbol indicates that the s Lock PLL is enabled When the decimal points are extinguished the s Lock PLL is disabled e Once you have activated or deactivated the s Lock PLL either rotate the encoder to advance to the next setup menu item or push and hold the encoder to exit the setup menu FILTER PCM DIGITAL FILTER RESPONSE The m920 provides the user with the ability to change the response of the digital filter used by the DAC when monitoring PCM sources Fast is the classic linear phase brick wall filter It has a steep roll off to prevent any high frequency signals from causing aliasing artifacts It also causes a con siderable amount of pre ringing and post ringing at the Nyquist frequency when passing transient information This filter is great for looking at con verter performance on a test bench where it might be subject to artificially high amplitude signals near 20kHz Slo
29. mbers and shows two large facing brackets Pushing and holding again returns the m920 to normal stereo op eration as indicated by the brackets changing back to the current output level numbers VOLUME MENU NAV In normal operation press ing the volume up or down buttons will change the selected m920 output level respectively in 0 5dB steps Also pressing the volume up or down buttons while the selected output is muted will unmute the output NOTE Pushing and holding the Volume up page 15 down buttons results in continuous volume changes The longer a button is held the quicker the volume level changes If the setup menu has been entered by pushing and holding the OUTPUT setup button the volume up and down buttons are used to navigate through the available setup menu items Apple Remote Control Operation 22222 In addition to the Grace Design wireless remote control the m920 can also be controlled by an Apple IR Remote Control The following section details all of the features available from the Apple IR Remote Control Several of the buttons on the remote have multiple functions based on operating mode and are described below To activate an m920 for use with a remote control please refer to the infrared remote control enable procedure in the accessing and using the setup menu chapter of this manual The factory default setting is active Please refer to the section Apple Remote Pairing for in
30. of our products to be free of defective parts and workmanship for a pe riod of five years This warranty period begins at the original date of purchase and is transferable to any person who may subsequently purchase the product during this time This warranty excludes the following conditions normal wear and tear misuse customer negli gence accidental damage unauthorized repair or modification cosmetic damage and damage incurred during shipment During the time of this warranty Grace Design will repair or replace at its option any defective parts or repair defective workmanship without charge provided the customer has appropriate proof of purchase and that the product has its original factory serial number In order for Grace Design to provide efficient and timely warranty service it is important that you mail the completed warranty registration card enclosed with all of our products within 10 days of the original date of purchase You may also register your product directly with Grace Design by telephone 303 823 8100 Monday Friday 9 00am to 5 00pm MST or you can register your product online at www gracedesign com This warranty is in lieu of all other warranties whether written expressed or implied INCLUDING ANY WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE In no event will Grace Design be liable for lost profits or any other incidental consequential or Ex emplary damages even if Grace Design is aware of
31. om the AES3 S PDIF or TOSLINK connectors Once phase lock with the incoming signal has been When listening to loudspeakers in a room your left ear hears sound primarily from the left speaker and vice versa but also receives a signal from the right speaker at a lower level and with some time delay compared to the right ear As well the right speaker sound that reaches the left ear does not have a flat frequency response as the sound waves have traveled around the shape of your head before reaching your left ear The brain uses delay level and frequency response characteristics to process the location of a sound and hence create an aural image When listening through headphones each ear only hears the sound from one transducer and the mix ing of signals between the ears does not exist In this situation the brain is left without many of the psycho acoustic clues required to generate a properly distrib uted image and an accurate sound stage The result is that instruments seem to cluster in the far left far right or center of your head Since the vital clues are achieved the DAC s which have been running off the original clock are switched to run off the ultra low jitter s Lock system clock If at any time s Lock is lost or not achieved the DAC s are run off the original Clock The s Lock system can effectively lock to input sample rates of 44 1kHz or 48kHz 5Hz 88 2kHz or 96kHz 10Hz and 176 4kHz or 192kHz 20Hz If
32. ount your m920 first install the 4 supplied metal rubber feet Simply thread the supplied feet by hand into the 4 vacant threaded holes in each corner of the underside of the m920 RACKMOUNTING For rack mount installation the m920 chassis has a 10 32 threaded insert mounting hole on the bottom page 5 towards the back Two m920 s can be mounted side 10 32 x 3 8 machine screw Do not use a screw by side in a standard 10 rack tray Use the supplied longer than 3 8 POWER CONNECTIONS AC POWER CORD The disconnect device for the m920 system is the Connect the supplied AC cord to the iec mains plug or the appliance coupler on the power power entry module on the rear panel supply cord The disconnect device must remain of the m920 For safety it is recom accessible and operable The power supply cord sup mended that the cable be connected to plied with the m920 must be connected to a mains a grounded outlet with a protective earthing connection outlet CHECK LINE VOLTAGE SETTINGS LOW VOLTAGE DETECTION The IEC power entry module has been set from the The m920 will automatically detect a low line volt factory to operate at the voltage required for your age condition In the event that line voltage drops part of the world However it s important to double below 85 VAC for 100 120 VAC or 170 VAC 200 check this in order to ensure no damage will come 240VAC the m920 will switch into low voltage to the unit if power is applied and the
33. setting is detection mode In this mode both headphone and incorrect line outputs are muted and the 7 segment led will begin to flash The m920 will automatically return to the previous operating state when proper line volt age is restored LINE VOLTAGE SELECTOR To change the line voltage remove the AC power chord from the power inlet then use a small screw driver to pry the fuse carrier out Remove both fuses POWER UP SEQUENCE from the fuse carrier and replace with the proper The m920 s headphone outputs are protected value fuse from the fuse chart below Carefully from any popping when the unit is turned on or off remove the grey colored fuse holder and re insert However if you are using the line outputs observ it into the fuse carrier with the proper line voltage ing proper power sequencing is recommended to showing through the small window Note that time avoid any potential popping in your speakers Before delay or slow blow fuses are required powering up your m920 make sure your monitor Voltage Fuse information speakers or power amps connected to your moni P COMSETNG LINE VOLTAGE FUSE VALUE tors are turned OFF Once the m920 and the rest of 110V 100 120V 250V T250mAL 220 220 240V SOV T 25mAL your audio system are powered up then turn on the power to your speakers or amplifiers When powering down first power OFF your speaker system and or power amps and then power down the m920 Turn power amps on la
34. st turn them off first fuse value table The input output interface connections high provided for interfacing with consumer level 10dBv lighted earlier in this manual are detailed below unbalanced analog sources Connections are made Please contact us if you have any questions regarding using standard RCA cables cable terminations or pinout specifications AES3 DIGITAL INPUT The stereo AES3 input is pro BALANCED ANALOG INPUTS The balanced stereo an vided via one female XLR connector This conforms alog input is provided via female XLRs Connection is to the AES3 standard Use of high quality 110 Ohm made using standard balanced XLR cables This input balanced cable is highly recommended is wired pin 1 shield pin 2 positive pin 3 negative S PDIF COAXIAL INPUT Standard coaxial stereo UNBALANCED ANALOG INPUT This stereo input is digital input The input impedance is 75 Ohms Use a page 6 quality 75 Ohm cable for connections to this input TOSLINK INPUT Standard stereo optical input con nector for use with consumer devices Use a stan dard TOSLINK optical cable for connections to this input USB INPUT The stereo USB input for connection to a host computer Use a USB 2 high speed type A to type B mini cable included with your m920 The type A connector is to be plugged in to the HOST PC and the type B mini connector is to be used with the m920 input Due to the very high speed opera tion of this interface we recommen
35. structions on assigning a specific apple remote to the m920 Apple remote button m920 function push hold MENU Enter Setup Menu MENU Pressing this button enters and exits the m920 setup menu like pressing and holding the encoder for 3 seconds on the m920 When exiting the setup menu all changes to the setup menu are saved PLAY PAUSE MUTE Pressing this button toggles the mute setting for the currently selected output on the m920 Once engaged active mute status will be reflected by the 7 segment display flashing on and off in regular intervals NOTE the small white plastic Apple Remote Control has the center button labeled as PLAY PAUSE however it functions as the CENTER button only with the m920 To disable muting simply press the PLAY PAUSE button again The output will return to the current level setting and the display will return to solid page 16 In addition to pushing the mute button mute can be turned off by making any volume change on remote control or on the m920 itself LEFT CROSSFEED Pressing this button toggles the x feed status on the m920 The current x feed status will be displayed momentarily on the m920 7 seg ment display as well as by the dedicated x feed LED to the right of the volume control Also pressing the x feed button while in the setup menu will return the m920 to normal operation CENTER OUTPUT TOGGLE ENTER Pressing this button during normal operation toggles between the
36. the incoming digital audio signal clock frequency is outside of these tolerances the s Lock circuit will not lock and the s Lock indicator on the m920 will extinguish The m920 features a second PLL in addition to the s Lock circuit This circuit provides a wide bandwidth lock range and achieves excel lent recovered clock jitter performance even when s Lock is inactive Note that in USB mode the m920 is the clock master so there is no need to lock to an incoming signal absent the brain has a difficult time deciding how to process the sounds coming from the headphone which can result in listening fatigue when listening for extended periods of time The m920 contains new crossfeed circuitry which electronically simulates the signal crossfeed that occurs in a real acoustic space and helps the brain es tablish instrument locations across the entire sound stage While it is difficult to perfectly model the very complex level delay and frequency response characteristics of the head the crossfeed circuitry in the m920 gives the brain some of the basic clues it needs and the result is a very pleasing simulation of an acoustic space while maintaining the tonality and balance of the original source page 9 Accessing And The m920 features a number of useful functions that can be accessed and adjusted entering and navi gating the setup menu To access the m920 setup menu simply press and hold the front panel encoder knob for 3 secon
37. the line outputs controlling your speakers and your headphones Instead of having to manually mute or turn down the volume when tog gling between outputs this mode handles it auto matically Once enabled selecting either line output turns that output on at its set volume and mutes the headphone outputs Selecting the headphone out put turns this output on at the set volume and mutes the line outputs Note the exclusive output mode is saved anytime the m920 is power cycled To activate exclusive output mode e Push and hold the rotary encoder to enter the setup menu Then rotate the encoder until you reach the exclusive output mode option as indicated by the letters EO e Push and release the encoder to toggle on which will be indicated by the illuminated the decimal points E 0 push and release again to toggle off e Once you have selected the output mode you require either rotate the encoder to advance to the next setup menu item or push and hold the encoder to exit the setup menu 36 d 2 as An optional high quality wireless remote control is available for control of the m920 The following section details all of the features available from the remote control Several of the buttons on the remote have dual functions accessed by either a push or a push and hold action and are described below To activate an m920 for use with a remote control please refer to the infrared remote control enable proced
38. the possibility of such damages In no event will Grace Design s liability exceed the purchase price of the product This warranty gives the customer specific legal rights The customer may also have other rights which vary from state to state Some states do not allow limitations on implied warranties or con sequential damages so some of the limitations of the above may not apply to a particular customer Revision Page Change y Initials _ a added minimum phase filter information 4 2 14 leg sd 23
39. tion of the 4 Referring to the diagram below move the L1 output as well as the line output mode selection jumpers to the indicated position m920 REAR PANEL J10 J11 J12 FIXED DAC OUTPUT SELECT RE L1 OUTPUT MODE FDO OUTPUT MODE Or T 39 Qr 4 8 PZ 26 je i J mum M R138 ott ru 130 459 M g d mac Dt 44 C146 R144 440141 R140 17 The firmware in the m920 can be upgraded using windows PC with USB port To get the current m920 firmware and DFU upgrade utility please go to www gracedesign com To display the currently installed m920 firmware version do the following 1 Turn off the m920 2 Select any input except USB 3 Press and hold the encoder button down and turn on the power to the m920 The current firmware revision will be displayed on the 7 segments Use the following process to update the firmware in the m920 using a Windows PC It is recommended that you turn off any powered speakers power amps that are connected to the m920 before proceeding with the firmware update 1 Connect the m920 to the PC via USB and turn on the m920 2 Start the XMOS USB Audio ST Firmware Upgrade application If the m920 is properly connected the Upgrade window should display Device opened X XMOS USB Audio 2 0 ST Firmware Upgrade If there is a problem with the connection the Upgrade window will display No device found Pleas
40. u may want indepen dent control of two different sets of monitors mains and nearfields One interesting possibility for having the two line outputs grouped is a simple 2 1 monitoring setup send one set to your monitors and the other to a subwoofer Use the level offset feature to trim either set of outputs accordingly To select between the two line output modes e Push and hold the rotary encoder to enter the setup menu Then rotate the encoder until you reach the two line output mode options as indicated by the letters L1 or L2 page 14 Push and release the encoder to toggle between either mode which again we be indicated by the letters L1 or L2 L1 is what refer to as grouped operation where both line outputs are selected and adjusted together in unison L2 is what we call round robin where each line output is selected and adjusted independently of each other e Once you have selected the mode you require either rotate the encoder to advance to the next setup menu item or push and hold the encoder to exit the setup menu NOTE When the m920 unbalanced line output 1 is configured for fixed DAC output the LINE OUTPUT MODE menu is not available In this configuration the volume control selection toggles between HP and L2 EXCLUSIVE OUTPUT MODE This mode allows you to toggle between all three outputs and mute the output s not selected The exclusive output mode can be very useful when ref erencing between
41. ues based on the position of the main LEDS indicate the base sample rate with the ap level rotary encoder The range of this display is propriate multiplier for 2x 4x and 8x rates 99 Note the decimal represents a 0 5dB DSD INDICATOR LED auto DSD detection from increment This display is also used to give the the selected digital input source user information in the setup menu 10 HEADPHONE OUTPUTS Two stereo headphone VOLUME 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 jacks wired in parallel S PDIF IN e TOSLINK I AES3 IN 10 9 8 7 6 5 1 BALANCED ANALOGINPUT standard female XLR connectors 2 UNBALANCED ANALOG INPUT standard RCA connectors 3 UNBALANCED LINE OUTPUT standard RCA connectors 4 BALANCED LINE OUTPUT standard 1 4 TRS connectors 5 AESDIGITALINPUT use 110 Ohm balanced q LINE OUT2 LINE OUT 1 GOO UNBAL IN BALIN cable 6 USBDIGITALINPUT standard USB type A to type B mini cable included 7 TOSLINK DIGITAL INPUT standard TOSLINK opti cal cable 8 S PDIF DIGITAL INPUT use 75 Ohm cable AC LINE VOLTAGE SELECTOR selects beteen 100 120VAC and 220 240VAC operation 10 ACLINEINPUT MODULE standard 3 prong AC cable included Unpacking and Installing yourm920 ss The m920 is shipped in one
42. ure in the accessing and using the setup menu chapter of this manual The factory default set ting is active MUTE EX OUTPUT Pushing this button toggles the mute setting for the currently selected output on the m920 Once engaged active mute status will be reflected by the 7 segment display flashing on and off in regular intervals To disable muting simply press the mute button again The output will return to the current level set ting and the display will return to solid In addition to pushing the mute button mute can be turned off by making any volume change on remote control or on the m920 itself Pushing and holding the mute button will toggle the exclusive output EO setting and will exit you from the submenu mode The current exclusive output status will be displayed momentarily on the m920 display X FEED EXIT SETUP Pushing this button toggles the x feed status on the m920 The current x feed status will be displayed momentarily on the m920 7 seg ment display as well as by the dedicated x feed LED to the right of the volume control Also pressing the x feed button while in the setup menu will return the m920 to normal operation Pushing and holding the X FEED exit setup button will if currently in the setup menu store all changes made and exit the setup menu OUTPUT SETUP Pushing this button during normal operation toggles between the 3 available outputs EP ai Andino dnies Te
43. w is also a linear phase filter but with a much slower roll off This filter has much less ringing and overshoot on transient material but can cause alias ing distortion when presented with high amplitude high frequency material The idea here is that in real music there is very little energy in the high frequency area of the spectrum so aliasing distortion will be negligible This filter is more musical than the Fast filter Minimum Phase has a similar roll off characteristic to the Fast filter but it moves all of the overshoot and ringing so that it occurs after a transient There is no pre ringing but it is at the expense of not being linear phase It is potentially better sounding be cause of this fact However the mechanisms for why it sounds better are not yet clearly understood To set the PCM filter setting e Push hold the rotary encoder to enter the setup menu Then rotate the encoder until you reach the Filter PCM screen as indicated by the FP symbol e Pushandrelease the encoder to enter the PCM filter readout e Rotate the encoder clockwise to select the fast rolloff response indicated by F e Rotate the encoder counter clockwise to select the slow rolloff response indicated by S e Rotate the encoder counter clockwise to select the minimum phase rolloff response indicated by P you have set the desired PCM filter response push and release the encoder to store the setting and return to the
Download Pdf Manuals
Related Search