M-Audio USB Audio Duo User Manual

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

What’s in the Box? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Quick Start Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Duo Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Minimum System Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Front Panel: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Back Panel: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Bottom of Unit: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Basic Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Hardware & Software Installation on the PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Windows XP Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Windows 2000 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Windows ME Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Hardware & Software Installation on the Mac . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Hooking up your USB Audio Duo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Using the Input and Output Level Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Using the Mic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Setting the Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Phantom Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Using the Pad Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Standalone Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Duo Operation on the PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

The USB Audio Configuration Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

The Duo and the Windows Sound System . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

The Duo, MME, and Your Music Program . . . . . . . . . . . . . . . . . . . . . . . . . . .16

ASIO/EASI Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

ASIO/EASI Control Panel and Operating Modes on the PC . . . . . . . . . . . . . .17

Advanced Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Duo Operation on the Macintosh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

The Macintosh Sound Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

ASIO Operation on the Macintosh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

ASIO Control Panel and Operating Modes on the Mac . . . . . . . . . . . . . . . . . .21

Optimizing Your System for USB Audio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Troubleshooting: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Before You Call Midiman/M-Audio Technical Support . . . . . . . . . . . . . . . . . .25

Limited Lifetime Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

DUO

Users Manuual

AUDIO

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 output, plus a headphone output for personal monitoring. Additionally, the Duo has a “Standalone” mode that lets you operate it as a mic preamp or A/D converter independent of your computer.

Please take the time to read this manual. It contains important information that will help you get the most out of your Duo.

What’s in the Box?

Your Duo box contains:

• This Manual.

• The Duo.

• One (1) Standard USB cable.

•

9V AC 1 Amp “Wall Wart” power supply.

Quick Start Guide

The USB Audio Duo is a powerful little device that you will find easy to use once you familiarize yourself with its many features. The many aspects of the Duo are detailed in this manual, and for that reason we suggest giving it a good read through.

Here is a basic outline of the steps you will need to take to get your Duo up and running:

1. Install the drivers, following the instructions for your particular platform and

operating system (see “Hardware and Software Installation” sections).

2. Hook up your microphone and/or other audio gear to the Duo inputs, and

connect the output(s) to your sound system, mix deck, or headphones (see section, “Hooking Up Your USB Audio Duo”).

3. Configure your music software to utilize the Duo as its audio interface.

4. Make music.

Whether your music program uses ASIO drivers, EASI drivers, Windows MME or Macintosh Sound Manager, will determine how you configure the Duo in your music program. There are entire sections devoted to using your Duo either on the PC or on the Mac.

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 indicator

LEDs per channel.

• S/PDIF digital output on gold-plated RCA jack.

• Headphone output with level control.

• 48V global phantom power with switch and indicator LED.

• 20dB pad available for each microphone input.

• Multitrack recording and mixing using the convenience of your USB port.

• PC drivers include Windows XP, 2000, ME and 98SE, ASIO, EASI

and WDM.

• Mac drivers include OS 9.1 and higher, Sound Manager, and ASIO.

Performance Specs:

• Dynamic Range (Direct Line In to Line Out): 105dB

• THD+N (Direct Line In to Line Out): <0.002%

• Dynamic Range (Mic In to Line Out): 107dB

• THD+N (Mic In to Line Out): <0.002%

Minimum System Requirements

Macintosh

• USB (native) equipped Mac G3.

• Mac OS 9.1 minimum.

• 64M available RAM for 44.1 or 48k operation, 128 recommended.

128M available RAM for 96k operation, 256M recommended.

Windows

• USB equipped Pentium.

• Windows 98SE or higher.

• 64M available RAM for 44.1k or 48k operation, 128 recommended.

Pentium 266 MHz MMX.

• 128M available RAM for 96k operation, 256M recommended.

Pentium II, 333 MHz.

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 potentiometer controls the amount of gain applied to the

microphone preamp. One Gain pot is provided for each mic input.

4. Clip LED: This LED responds to the signal present at the Duo’s respective Mic

input, and will begin to light when the signal reaches clipping.

5. Sig. (Signal) LED: This LED responds to the signal present at the Duo’s

respective Mic input, and will begin to light when a nominal signal is present at the input.

6. Standalone: Pressing in and engaging the Standalone switch will connect the

Mic and Line inputs directly to the analog Line Outs, S/PDIF output, and the Headphone output. Standalone mode allows for use of the Duo as a mic preamp and/or analog to digital converter independent of the computer. This feature of the Duo also allows you to directly monitor the inputs when connected to a computer.

7. Headphone Out Jack: This output jack is designed to connect to a 1/4” TRS

plug, typically for use with a set of stereo headphones. The source for the signal at the Headphone Out is identical to the Line Outs.

8. Headphone Level: This knob controls the amount of monitoring level sent to

the Duo’s Headphone Out jack.

9. Phantom Power Switch & corresponding LED: Pressing in and engaging the

Phantom Power switch will send 48V of phantom power to the Duo’s Mic inputs. When phantom power is switched on, the corresponding Phantom Power LED will light and remain lit.

10. Power Switch & corresponding LED: Pressing in and engaging the Power

switch will power up the Duo, provided that the proper power supply is connected to the 9V AC Power jack. When power is switched on, the corresponding Power LED will light and remain lit.

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” switch in the In position, S/PDIF Out receives audio from the Mic or Line inputs of the Duo.

4. Line Outputs: These 1/4” TRS jacks, labeled “Outputs,” are the main outputs

for the Duo. Using a TRS (tip-ring-sleeve) 1/4” plug, the Duo will provide a balanced line-level output. Using a TS (tip-sleeve) 1/4” plug, the outputs will be unbalanced. The Line Outs receive audio from one of two sources. With the “Standalone” switch in the Out position, the Line Outs receive audio from the computer’s software outputs. With the “Standalone” switch in the In position, the Line Outs receive audio from the Mic or Line inputs of the Duo.

5. Line Level Output Switch: This switch sets the operating line level for the Duo

Line Outs. In the ‘out’ position, the Duo Outputs 1 & 2 are set to +4dBu line level operation. Pressing and locking this switch to the in position sets these outputs to a -10dBV line level.

6. Line Inputs: These 1/4” jacks accept TS 1/4” plugs. These are line level

inputs, and generally will be connected to the outputs of a line level instrument or preamp.

7. Mic Inputs: These are the balanced, low impedance microphone inputs to the

pre-amp channels. NOTE: When phantom power is engaged, power is sent to BOTH of these channels. An XLR jack is disabled when an instrument is plugged into the corresponding 1/4” jack.

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 screwdriver or similar instrument, you can change the position of each switch. The default setting is both switches “down,” which is the position closest to the numbers 1 and 2, representing a sample rate of

44.1kHz. The full list of settings is as follows:

1. 44.1kHz: Both switches in the down position (down being in the direction of

the numbers).

2. 48kHz: Switch #1 down, switch #2 up.

3. 88kHz: Switch #1 up, switch #2 down.

4. 96kHz: Both switches in the up position.

Basic Theory of Operation

The Duo attaches easily to your computer’s USB port--no tools or computer disassembly is necessary. Following the installation of the included driver software, the Duo can be attached or unattached to your computer according to your needs.

The Duo is a 2x2 audio interface, providing two channels of audio TO the computer and two channels of audio

FROM the computer. The Duo gives you two high quality, low impedance Mic Inputs on XLR connectors, plus two unbalanced Line Inputs on 1/4” TS jacks that can be used alternately. When a Line Input is in use, the corresponding Mic Input is disabled.

The Duo can be configured for +4 or -10 line level operation simply by pressing the “Line Level” buttons on the front and/or back panels. This allows for seamless integration into the studio, giving you compatibility with professional balanced (balanced TRS, +4dBu) or semi-pro (unbalanced TS, -10dBV) audio devices (see section, “Using the Input and Output Level Switches”).

Audio from your computer is sent simultaneously to the Duo’s two balanced/unbalanced Line Outputs on 1/4” TRS jacks, the coaxial S/PDIF Output, and the Headphone Out. The Duo can also be used in a Standalone mode, which connects the Mic/Line inputs directly to the Line Out, S/PDIF Out, and Headphone Out. Pressing the “Standalone” switch turns the Duo into a mic preamp and A/D converter that can be used independent of the computer. Standalone mode can also give you a direct monitoring option when using the Duo as an audio interface with your computer.

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 when using a music program that takes advantage of them, such as Cakewalks’s

Sonar.

Hardware & Software Installation on the PC

Here is a simple, step-by-step procedure for attaching and powering up the Duo. See the section, “ASIO/EASI Operation” for information on configuring ASIO or EASI drivers.

1. Plug the Duo wall-wart into your wall receptacle and to the Duo 9vAC power

jack. Use only the included power supply, or a similar power supply with the exact same specifications.

2. Connect the USB cable to your computer and the Duo (one end of the cable is

for the computer, and the other is the device end). Find an appropriate spot on your desktop or work area for the Duo.

Windows XP Installation

1. Boot Windows XP with your M-Audio USB Duo powered OFF. After

Windows XP has been booted, power up the Duo.

2. Windows XPwill then detect and automatically install the drivers for the USB

Composite Device and USB Audio Devices.

3. Insert the included Driver CD into your computer’s CD drive. Assuming that

your CD drive is the “D” drive, locate the Duo driver at D:\USB_AUDIO\DUO\WINXP.

4. Run the program “Duo XP PostInstaller” program by double clicking on it.

This will install the Duo’s Windows MME drivers, plus the ASIO and EASI drivers. Windows will show the "Digital Signature Not Found" Dialog. Press "Continue Anyway."

5. Restart the computer after the installation is finished.

Windows 2000 Installation

1. Boot Windows 2000 with your M-Audio USB Duo powered OFF.

2. Insert the included Driver CD into your computer’s CD drive. Assuming that

your CD drive is the “D” drive, locate the Duo driver at D:\USB_AUDIO\DUO\WIN2000.

3. Run the "Duo W2k Installer" program by double clicking on it.

4. Windows will show the "Digital Signature Not Found" Dialog. Press "Yes."

5. Connect and power ON your M Audio USB Duo.

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 will proceed with the installation of the "USB Composite Device"

driver. Note: If the "USB Composite Device" has already been installed then Windows will skip this step. This will occur if another USB audio device had been installed on your system at any time.

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 "Specify the location of the driver" item, and

then click "Next".

5. Windows will ask you where you want it to search for the drivers. Remove the

check marks from all of the optional search locations except "Specify a location." Insert the included Driver CD, click “Browse,” then, on your computer’s CD drive, locate the folder “USB_AUDIO\DUO\WINME.” Click "Next".

6. On the next screen, Windows will indicate it has found an updated driver for

this device. Keep the updated driver selected and click "Next".

7. Windows will report that is it ready to install the driver. Click "Next" to continue.

8. Windows will process the files and then indicate it has finished installing the

software that your new hardware device requires. Click the "Finish" button. You will need to repeat these steps as many times as Windows finds a new hardware device. By the time everything is finished you will have installed the Duo’s Windows MME drivers, plus the ASIO and EASI drivers.

9. Windows might indicate it cannot find a file it is attempting to copy from the

Windows ME CD. If so, insert your Windows ME CD, then use the Browse button to point to this CD and continue.

10. Windows will process the files and then indicate it has finished installing the

software that your new hardware device requires. Click the "Finish" button.

Note: At this point you might need to wait for several minutes while Windows configures the hardware. Please be patient.

11. Restart the computer after the installation is finished.

Windows 98 Second Edition Installation

1. Boot Windows 98 SE with your M-Audio USB Duo powered OFF. After

Windows 98 SE has been booted, power up the Duo.

2. Windows will proceed with the installation of the "USB Composite Device"

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, remove the check marks from all of the optional search

locations except "Specify a location." Insert the included Driver CD, click “Browse,” then, on your computer’s CD drive, locate the folder “USB_AUDIO\DUO\WIN98SE.” Click "Next".

6. On the next screen, Windows will indicate it has found an updated driver for

this device. Keep the updated driver selected and click "Next".

7. Windows will report that is it ready to install the driver. Click "Next" to

continue.

8. Windows will process the files and then indicate it has finished installing the

software that your new hardware device requires. Click the "Finish" button. You will need to repeat this step as many times as Windows finds a new hardware device. By the time everything is finished you will have installed the Duo’s Windows MME drivers, plus the ASIO and EASI drivers.

9. Windows might indicate it cannot find a file it is attempting to copy from the

Windows 98 CD. If so, insert your Windows 98 Second Edition CD, then use the Browse button to point to this CD and continue.

10. Windows will process the files and then indicate it has finished installing the

software that your new hardware device requires. Click the "Finish" button.

Note: At this point you might need to wait for several minutes while Windows configures the hardware. Please be patient.

11. Restart the computer after the installation is finished.

Hardware & Software Installation on the Mac

Here is a simple, step-by-step procedure for attaching and powering up the Duo on the Macintosh Computer. The Duo comes with an installer program that will place all driver components in their proper folders.

The installer program will give you a list of ASIO compliant programs that it will recognize and subsequently install the appropriate ASIO driver if the program exists on your system (that being said, it is a good idea to first install your music program before installing the Duo drivers, though Duo drivers can be installed again if necessary). Otherwise, the Duo ASIO drivers (and the remaining ASIO drivers that have not been used) will be placed in a folder on your desktop called “Duo ASIO,” and must be inserted into your music program’s ASIO folder manually, provided that your music program uses ASIO.

1. On the Driver Disk that came with your Duo, locate the folder

“USB_Audio_Duo” that contains the USB Duo Installer for the Macintosh.

+ 18 hidden pages