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TM
DUO
AUDIO
Users Manuual
TM
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
What’s in the Box? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Quick Start Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Duo Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Introduction Congratulations on your purchase of the Duo, designed and manufactured by M-Audio. The Duo is a complete USB audio solution for your PC or Macintosh computer. With two inputs and two outputs of 24-bit audio and up to 96kHz sampling frequencies, coupled with two high quality mic preamps, the Duo utilizes the power and convenience of USB audio in a convenient half-rack size unit. The Duo lets you operate its analog inputs and outputs at either +4 or -10 line levels, gives you a S/PDIF
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Other aspects of the Duo, including use of the +4/-10 line level switches, phantom power, etc., are also covered in depth. Also, be sure and check out the section, “Optimizing Your Sytem for USB Audio,“ later in the manual. So, please read on, and enjoy your Duo. Duo Features • 2 critically acclaimed DMP2 mic preamps with individual gain controls. • Balanced/unbalanced line outputs on 1/4” TRS, unbalanced line inputs on 1/4” TS. • Preamps have maximum gain of 60dB with signal and clip indi
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Front Panel: 1. Line Level Input Switch: This switch will set the input line level for the Duo. With the switch in the out position, the Duo will operate at a +4dBu line level. Pressing and locking this switch to the in position will set the operating line level to -10dBV. 2. Pad Switch: One pad switch has been provided for each mic input on the Duo. Pressing in and engaging the Pad switch will apply a 20dB pad, or “cut,” to the microphone input prior to the microphone preamp. 3. Gain: This p
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Back Panel: 1. 9V AC Power Jack: This power jack accepts a 9v AC 1 Amp 2.5mm power supply. This power supply is included with your Duo, and ONLY the proper supply should be used. 2. USB Connector: This jack accepts the device-end of a standard USB cable. 3. S/PDIF Out: This coaxial RCA digital audio output connector receives audio from one of two sources. With the “Standalone” switch in the Out position, the S/PDIF Out receives audio from the computer’s software outputs. With the “Standalone”
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Bottom of Unit: At the bottom of the unit are two DIP switches that will set the sampling rate while the Duo is used in standalone mode. The Duo can be used as an A/D converter independent of the computer, using either the line inputs or the mic preamp inputs. The relative positions of these DIP switches will determine the sample rate at the S/PDIF output when used in standalone mode. You will see the rather tiny numbers 1 and 2 at the bottom of the set of two DIP switches. Using a miniature s
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The Duo can be used with the Sound Manager on the Macintosh, or with the Windows Sound System in Windows, and therefore can operate as your system sound card. If your software is ASIO or EASI compliant, such as Steinberg’s Cubase or Emagic’s Logic, we suggest using the ASIO or EASI drivers. These drivers will allow you to monitor audio through your music program with greatly reduced latency. The WDM drivers that are used in Windows ME, 2000, and XP will give you similar monitoring capability whe
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6. You will then see Windows 2000 detect and automatically install the driver for the USB Composite Device. 7. Windows will detect and automatically install a number of drivers. As it does this, it will show the "Digital Signature Not Found" Dialog a few times. Press "Yes" for each dialog. 8. Restart the computer after the installation is finished. Windows ME Installation 1. Boot Windows ME with your M-Audio USB Duo powered OFF. After Windows ME has been booted, power up the Duo. 2. Windows w
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driver. Note: If the "USB Composite Device" has already been installed then Windows will skip this step. This will occur if a USB audio device had previously been installed in your system. 3. Windows will report that “USB Duo New Hardware” was found. When the Add New Hardware Wizard reports that it wants to search for a driver for a USB Composite Device, click "Next". 4. On the next screen select the "Search for the best driver for your device." item, and then click "Next". 5. On the next screen
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Double click on the Installer program. The Installer program installs all Duo extensions, and installs the ASIO driver in a folder named “Duo ASIO”on your desktop. 2. locate the program’s ASIO folder (it will be found within the program’s folder on your Macintosh HD). Drag the ASIO driver (located in the “DUO ASIO” folder created by the Installer) to that folder. 3. Properly shut down the computer. 4. Plug the Duo wall-wart into your wall receptacle and to the Duo 9vAC power jack. 5. Connect
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speakers, or a headphone amplifier, or to the inputs of a mixing console. Again, check your device’s documentation for information on its operating line level, and see the section, “Using the Input and Output Level Switches.” The Duo’s S/PDIF Out can be connected to any S/PDIF capable device, such as a DAT or MiniDisc with coaxial S/PDIF inputs. The diagrams below illustrate two scenarios, intended as examples of how the Duo might be used. Typical Setup #1 shows the Duo with a microphone plugged
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jacks. Check your source or target device’s documentation for more information on its operating line level. Using the Mic Inputs The Duo gives you two completely independent channels of high gain, ultra low noise pre-amps. Each channel provides low impedance microphone inputs on XLR connectors with optional phantom power. Dynamic, condenser, or any type of low impedance microphone will interface easily with the Duo’s Mic Inputs. You may also attach a direct box or passive transformer to the Duo
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Phantom Power Unlike dynamic microphones, many "condenser microphones" need to receive a DC voltage (generally 48v) from an external source before they can generate an output signal. If the condenser mic doesn’t come with its own power supply, then phantom power must be applied from the pre-amp. Pressing the "Phantom Power" button and engaging phantom power on the Duo will send the necessary voltage to BOTH of the XLR Mic Inputs. Phantom power will not affect a dynamic mic adversely, so its oka
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at either the Mic Inputs or the Line Inputs of the Duo. You will, however, not be able to hear the software outputs from your computer in this case, so this option may only be useful to you when laying down your first recorded tracks, i.e., when there is no other audio playing back from your computer. In cases #1 and #2, the sampling rate for the Duo’s A/D converter will be determined by the DIP switch settings on the bottom of the unit. See the section, “Bottom of the Unit” earlier in this manu
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The USB Audio Configuration Manager, when it is first installed, defaults to the “ASIO/EASI” setting. If you are using an ASIO compliant program such as Steinberg’s Cubase or Nuendo, or a program that uses “EASI” drivers such as Emagic’s Logic, then you should leave the configuration manager set to “ASIO/EASI.” The Duo provides its own ASIO and EASI drivers, and the music program you use should be set up to utilize the Duo’s ASIO driver (see the section, “ASIO/EASI Operation”). If, on the other
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3. Power down the Duo, then power it back up. This will reinitialize the Duo. 4. Go to Start | Settings | Control Panel | Multimedia, and set the playback (and record) device to “USB Audio Device.” Click Apply, then click “OK” to close. There’s no need to change the setting for your Windows Sound System M-Audio device, should you choose to use the ASIO or EASI drivers in a music application, even though you will be using the USB Audio Configuration Manager in the “ASIO/EASI” setting. However, yo
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automatically during the normal installation procedure. The USB Audio Configuration Manager defaults to ASIO/EASI operation, so there’s no need to change any settings there. NOTE: You may have the Windows sound system set to “USB Audio Device” while the USB Audio Configuration Manager is set to “ASIO/EASI” for ASIO or EASI operation. However, the Windows MME drivers are inactive in this instance, so no Windows sounds will be heard. Once the drivers are installed, you may open your music program
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To launch the ASIO or EASI control panel from the USB Configuration Manager: 1. Double click the M-Audio logo in your Windows System Tray, located on the right side of your Windows Taskbar. (You can also right-click the icon, then choose “Open M-Audio USB ASIO/EASI Control Panel.”) 2. Click the button, “Open ASIO/EASI Control Panel.” 2. In the column labeled “Interface,” choose which driver panel you wish to launch--either ASIO or EASI. 3. In the column labeled “Device,” choose which M-Audio US
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a selection. At the 24-Bit/Sample setting, both stereo input and output pairs are also available. The maximum sample rate will still be 48000 Hz. With both stereo pairs enabled at a Bitwidth setting of 24-bits, the Duo will also operate as a 2x2 audio device. In this mode, the Duo is capable of 48kHz or 44.1kHz at either 24- or 16-bits, as set by the music program. In the “Available Channel Sets” dropdown list, you may also select either”Channels 1&2 In” or “Channels 1&2 Out.” The Duo will perf
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In the M-Audio USB ASIO Driver control panel, to the right of the Bitwidth section, you will see a “Latency” drop-down list that will set the Duo’s buffer size. A lower latency setting represents a smaller buffer size, with the lower setting being desirable when using the ASIO drivers. How low you can set the latency will depend on several factors, such as your system’s performance and the performance of the music program itself. Try the “High” setting first (which is the default, as shown in t
