ART USB Mix

Overview

The ART USB Mix Three Channel Microphone, Instrument, and Line Mixer / Computer Interface is a compact, versatile audio interface designed for computers. It converts analog signals from various audio sources into a digital signal that your computer can process. The USB Mix can also function as a standalone mixer via its main mix outputs. It serves as an excellent starting point for personal home studio recording or mobile location recording, enabling users to record podcasts, songs, voiceovers, or jam sessions.

Features

• USB powered, requiring no external power supply when connected to a computer.
• Microphone (balanced XLR) input or instrument (unbalanced 1/4" TS) input with switchable impedance.
• Switchable low-noise +48V phantom power for microphones.
• Balanced 1/4" TRS inputs for stereo or mono line-level sources.
• 1/4" TRS output jacks compatible with balanced or unbalanced lines.
• Stereo 1/4" TRS headphone jack with independent level control for monitoring.
• Independent controls for input sets, main output, and headphone monitor.
• Green/Red LED signal/clip indicator.
• Switchable assignment of USB playback to channels 2 and 3.
• USB 2.0 compliant.
• No special drivers required for most modern versions of Windows, Mac OS, and Linux.
• Includes USB cable, AC adapter, and Audacity recording software.
• Rugged steel case construction.

Important Safety Instructions

[!] Warning: This symbol indicates the presence of uninsulated dangerous voltages inside the enclosure that may be sufficient to constitute a risk of electric shock. Do not open.

[i] Information: This symbol indicates important operating and maintenance instructions in the accompanying literature. Please read the manual.

Read Instructions

Retain these safety and operating instructions for future reference. Heed all warnings printed here and on the equipment. Follow the operating instructions printed in this user guide.

Do Not Open

There are no user-serviceable parts inside. Refer any service work to qualified technical personnel only.

Power Sources

Only connect the unit to mains power of the type described in this user guide or marked on the rear panel. The power source must provide a good ground connection.

Power Cord

Use the power cord with a sealed mains plug appropriate for your local main supply, as provided with the equipment. If the provided plug does not fit your outlet, consult your service agent. Route the power cord so that it is not likely to be walked on, stretched, or pinched by items placed upon or against it.

Grounding

Do not defeat the grounding and polarization means of the power cord plug. Do not remove or tamper with the ground connection on the power cord.

Moisture

To reduce the risk of fire or electrical shock, do not expose the unit to rain, moisture, or use in damp or wet conditions. Do not place containers of liquid on the unit, as spills may enter openings.

Heat

Do not locate the unit in a place close to excessive heat or direct sunlight, as this could be a fire hazard. Locate the unit away from equipment that produces heat, such as power supplies, power amplifiers, and heaters.

Environment

Protect the unit from excessive dirt, dust, heat, and vibration during operation and storage. Avoid tobacco ash, drink spillage, and smoke, especially that associated with smoke machines.

Handling

Protect the controls from damage during transit. Use adequate padding if you need to ship the unit. To avoid injury or equipment damage, take care when lifting, moving, or carrying the unit.

Servicing

Switch off the equipment and unplug the power cord immediately if it is exposed to moisture, spilled liquid, or if the power cord or plug becomes damaged during a lightning storm, or if smoke odor or noise is noted. Refer servicing to qualified technical personnel only.

Installation

Install the unit in accordance with the instructions printed in the user guide.

Installation

1. Connect your audio device cables to the XLR or 1/4" TS CH1 INPUT or 1/4" TRS CH2-CH3 INPUT connectors. If using the CH1 INPUT with a 1/4" TS plug, select the INST-Hi-Z or LINE setting.
2. Connect the USB Mix's USB TO COMPUTER connection on the back panel to an appropriate USB input on your computer using the supplied USB cable. You can also connect cables between the MAIN MIX OUTPUT 1/4" TRS jacks and an analog audio input, such as an amplifier.
3. Connect a pair of headphones to the MONITOR OUTPUT 1/4" TRS jacks if you wish to monitor the signal locally.
4. USB BUS POWER: No external power connection is needed. Power is supplied over the USB connection. The front panel POWER LED indicates that USB power is present when the USB cable is connected to a live USB jack or the included AC power adapter. If connecting to a computer USB input, it is best to connect directly to the computer or, if using a USB hub, ensure it is a powered hub to provide ample power for the USB Mix.

Monitoring What You Record

The USB PLAYBACK TO CH2-CH3 pushbutton switch, when engaged, mixes the preamp signal with the computer's playback signal. Typically, either a local audio source or the computer is playing back, but not both simultaneously. You can listen to either the preamp or the computer without changing settings. You can also hear computer alert signals while listening to recordings if these alerts are routed to the USB CODEC in your computer's sound control panel.

Some recording programs and computer systems offer a "Play-Through" function, which can be enabled via software or hardware. When play-through is active, the computer outputs the audio being recorded at the same time it is being recorded. This introduces a short delay (latency). There is also a potential for the computer's audio inputs and outputs to be inadvertently connected, creating a feedback loop that can produce very loud and disturbing sounds. Therefore, play-through is usually disabled by default in both software and hardware.

If software/hardware play-through is enabled and the USB PLAYBACK TO CH2-CH3 pushbutton switch is engaged, you will likely hear the original signal along with the delayed computer audio, creating an echo effect. This is normal behavior. To avoid this, it is preferable to leave play-through disabled when using the USB PLAYBACK TO CH2-CH3 function.

Connections and Controls

Front Panel Diagram Description: The front panel features input connectors on the top left: CH1 INPUT (combination XLR and 1/4" TS jack) and CH2-CH3 INPUT (two 1/4" TRS jacks). To the right are output connectors: MAIN MIX OUTPUT (1/4" TRS jacks) and MONITOR OUTPUT (1/4" TRS jack with headphone symbol). Below the inputs are controls for CH1, CH2-CH3, and MAIN MIX. These include PHANTOM POWER (+48V) switch, USB PLAYBACK TO CH2-CH3 switch, GAIN control for CH1, LEVEL control for CH2-CH3, and LEVEL control for MAIN MIX. Indicator LEDs are present for CLIP/SIGNAL status.

CH1 INPUT

The channel one input is a combination XLR or 1/4" TS jack. The XLR input is balanced and supports switchable phantom power, suitable for microphones and other balanced output audio sources. The 1/4" TS jack is unbalanced and features switchable impedance characteristics, designed for line-level signals or musical instruments like electric guitars.

CH2-CH3 INPUTS

The channel two and three inputs are 1/4" TRS jacks, designed for balanced line-level signals, though unbalanced signals can also be used. Plugging a source into the top (L) jack without anything in the bottom (R) jack routes the signal to both output channels. Otherwise, these inputs function as two separate mono signals or one stereo signal.

MAIN MIX OUTPUTS

The main mix outputs are 1/4" TRS jacks. While not true balanced outputs, they can be connected to balanced inputs while retaining many benefits of balanced lines. These outputs are typically used to connect directly to a power amplifier, powered monitors, or a recording system.

MONITOR OUTPUT

The monitor output is a 1/4" TRS jack designed to drive stereo headphones. It has its own independent level control.

USB TO COMPUTER

The USB connector is a standard Type B jack. A standard Type A to Type B USB cable (included) connects the USB Mix to your computer. The USB Mix can also be used without a computer by connecting the cable to the included AC to USB adapter.

Controls and Indicators

1/4" INPUT IMPEDANCE (CH1 INPUT)

This pushbutton switch adjusts the impedance for signals connected to the CH1 INPUT 1/4" TS jack. The LINE (out) position offers lower impedance, suitable for line-level signals from keyboards, acoustic guitars with preamps, or active bass pickups. The INST - HI-Z (in) position provides higher impedance, suitable for instruments like electric guitars.

PHANTOM POWER and +48V LED (CH1 INPUT)

This pushbutton switch controls the application of 48V DC to the CH1 INPUT XLR connector for microphones requiring phantom voltage. In the OFF (out) position, no phantom power is applied, and the +48V red LED is off. Pressing the button (ON position) applies phantom power and illuminates the +48V LED.

GAIN and CLIP CH1 LED (CH1 INPUT)

This control adjusts the gain of the CH1 preamp section. It should typically be adjusted so that the CLIP CH1 LED illuminates only during the loudest audio passages on CH1.

USB PLAYBACK TO CH2-CH3 (CH2-CH3 INPUT)

This pushbutton switch allows mixing of USB audio from your computer with signals from CH1, CH2, and CH3. In the OFF (out) position, no USB audio is mixed. Pressing the button (ASSIGN position) mixes in the USB playback signal. Refer to the "Monitoring What You Record" section for more details. Note that the relative levels of CH2-CH3 signals are fixed with respect to the USB signal level.

LEVEL (CH2-CH3 INPUT)

This control adjusts the level of the CH2-CH3 signal (which may include USB playback audio) relative to the CH1 signal.

POWER LED

Indicates when the USB Mix is receiving power from the USB connector and is ready for operation.

LEVEL and CLIP = RED / SIGNAL = GREEN LED (MAIN MIX)

This control adjusts the overall level of the mixed signal output to the MAIN MIX OUTPUT jacks and to the computer via the USB connection. It should typically be adjusted so the LED remains mostly green, turning red only during the loudest audio passages.

MONITOR PHONES

This control adjusts the audio level sent to the MONITOR OUTPUT jack. The monitor output level is independent of the main mix level setting.

USB Computer Settings

Once the USB connection is established and the computer is powered on, the computer will supply power to the USB interface circuitry via the USB bus. The unit will attempt to automatically set your computer's "Default Audio Device" to "USB Audio CODEC". While this often happens automatically upon first connection, manual selection may be necessary. Similar settings might be required within your specific audio application (consult its instructions). These settings should be made while the USB Mix and computer are connected and powered on.

Windows 7

Navigate: Start => Settings => Control Panel => Sound => Playback Tab and Recording Tab. Select: "USB Audio CODEC". Then, in the Recording Tab, go to Properties => Advanced and set the Default Format to: "2ch, 16bit, 44.1kHz". Also, in Recording Tab => Properties => Levels, set the level to "4".

Windows Vista

Navigate: Start => Settings => Control Panel => Sound => Playback Tab and Recording Tab. Select: "USB Audio CODEC". Then, in the Recording Tab, go to Properties => Advanced and set the Default Format to: "2ch, 16bit, 44.1kHz". Also, in Recording Tab => Properties => Levels, set the level to "25".

Windows XP

Navigate: Start => Settings => Control Panel => Sounds and Audio Devices => Audio. Select "USB Audio CODEC" as the Sound playback and recording Default device. Alternatively, go to Programs => Accessories => Entertainment => Volume Control => Options => Properties and select "USB Audio CODEC" as the mixer device.

Windows 98SE

Navigate: Settings => Control Panel => Multimedia. Choose "USB Audio Device" as the preferred device.

Mac OS X+

Navigate: System Preferences => Sound. Choose: "USB Audio CODEC".

Mac OS 9.1+

Navigate: Control Panels => Sound. Choose: "USB Audio CODEC".

After these settings are made, your computer's audio output ("Speaker") will be set to the "USB Audio CODEC", routing playback audio to the USB Mix. This must be done with the USB Mix connected and powered on. If you prefer, computer output can be routed to your computer speakers by selecting them for "OUTPUT" instead of "USB Audio CODEC" in the setup procedures. Your computer will automatically reconfigure itself to these settings each time the USB Mix is reconnected. Your recording software may also select specific inputs or outputs.

Note 1: For Windows 7 or Vista, it is crucial to set the Default Format and Microphone Level as described, as Windows' default settings may not be correct for proper USB Mix operation. Once changed, these settings are remembered.

Note 2: The USB Mix interface uses the standard "USB Audio CODEC". This driver is integrated into most modern operating systems, including Linux. Setup details for Linux may vary by version and are beyond the scope of this document. The key is to locate "USB Audio CODEC" as the recording source or playback monitor output when the USB Mix is connected.

Warranty Information

Limited Warranty

Applied Research and Technology (ART) provides warranty and service for this unit according to the following terms. ART warrants to the original purchaser that this product and its components will be free from defects in workmanship and materials for a period of three years from the date of purchase. ART will, at its discretion and without charge, repair or replace defective products or component parts upon prepaid delivery to the factory service department or an authorized service center, accompanied by proof of purchase (valid sales receipt).

Exclusions

This warranty does not cover misuse, abuse, unauthorized alterations, or repairs. The warranty is void if the serial number is altered, defaced, or removed. ART reserves the right to make design changes or improvements without obligation to apply them to previously manufactured products. ART is not liable for consequential damages, including loss of use. Some states do not permit limitations on incidental or consequential damages, so these limitations may not apply to you. This warranty grants specific rights, and you may have additional rights that vary by state.

For units purchased outside the United States, an authorized distributor of Applied Research and Technology will provide service.

Service

The following information is provided for instances where your unit may require service:

1. Verify the unit is the cause of the problem. Ensure it has power, all cables are correctly connected and functional. Consult your dealer for troubleshooting assistance.
2. If the ART unit is suspected to be faulty, visit www.artproaudio.com. Contact Customer Service for assistance or request a Return Authorization in the "resources" area of the website.
3. If returning the unit for service, pack it in its original carton or a suitable substitute. The original packaging may not be ideal for shipping; consider placing it in another box. Clearly print the RA number on the outside of the shipping box and your return shipping address.
4. Include with your unit: a note with the RA number, your contact information (including return shipping address – P.O. boxes are not accepted – and a daytime phone number), and a description of the problem, preferably attached to the unit. Also include a copy of your purchase receipt.

Please fill in the following information for your reference:

Date of purchase: ___________________________________________

Purchased from: ___________________________________________

Serial Number: ___________________________________________

Specifications

Note: 0 dBu = 0.775Vrms

ART maintains a policy of constant product improvement. Therefore, specifications are subject to change without notice. Visit www.artproaudio.com for the latest information and support.