Using a MOTU Audio Interface as a Standalone A/D or D/A Converter
- Article #1712935
- Updated on Mar 20, 2012 at 10:07 PM
In this example, an 828mk3 will be configured as a standalone A/D converter using its ADAT optical output by patching its analog inputs to its ADAT outputs:
- Connect the 828mk3 to the computer by FireWire, and turn on the interface.
- Open CueMix FX. Choose the Inputs tab, and then enable the Stereo button on the channel strips for analog inputs 1, 3, 5, and 7. (They will now appear as Analog 1-2, Analog 3-4, Analog 5-6, and Analog 7-8.)
- Choose the Mixes tab, and select Bus 1 in the mix bus menu.
- Set the mix bus output to ADAT A 1-2 by selecting the output pair in the bus output menu above the mix bus master fader. Set the master fader level to 0 dB.
- Mute all input channels except Analog 1-2. Set the Analog 1-2 fader to 0 dB. Set the balance control to 0.
- Select Bus 2 in the mix bus menu.
- Repeat the process with Bus 2 to route analog inputs 3-4 to ADAT A outputs 3-4. Then continue with Bus 3 (Analog 5-6 to ADAT A 5-6) and Bus 4 (Analog 7-8 to ADAT A 7-8).
- Open MOTU Audio Setup. Set the 828mk3’s sample rate and clock source appropriately.The 828mk3’s sample rate should match the sample rate of any connected digital audio devices. Generally, the 828mk3’s clock source should be set to Internal when it is being used as an A/D converter. However, these settings may be changed under some circumstances.
- Wait about one minute for the new settings to be saved to the 828mk3’s internal memory, and then disconnect the FireWire cable from the back panel of the interface.
- Connect the 828mk3’s ADAT A output to the ADAT optical input of another device. If the 828mk3 is the master clock device, then set the second device’s clock source to its ADAT optical input, and set its sample rate to match the 828mk3’s sample rate.
This configuration will be similar for all MOTU audio interfaces with features similar to the 828mk3 (such as the 896mk3, UltraLite mk3, and Traveler mk3). If you would like to configure your MOTU interface as a digital-to-analog converter (instead of an A/D converter), follow the steps above but choose digital inputs and analog outputs rather than analog inputs and digital outputs. It is important that the clock source and sample rate are set properly for both transmitting and receiving devices.
The MOTU 2408mk3 audio interface automatically switches into a standalone converter mode when it is disconnected from the PCI-424 card or when the computer is turned off. (This also applies to the earlier models, the original 2408 and the 2408mkII.)
In this example, a 2408mk3 will be configured as a standalone D/A converter using one of its ADAT optical inputs:
- Disconnect the AudioWire cable from the back panel of the 2408mk3, or turn off the computer. The interface will switch to the standalone converter mode.
- Use the Select and Set buttons on the front panel of the interface to choose these settings:
- Source: ADAT Bank A
- Bounce: 1-2 (Swap L&R disabled)
- Clock: 44 Dig (sample rate is 44.1 kHz, clock source is digital input)The 2408mk3’s sample rate should match the sample rate of any connected digital audio devices. Generally, the 2408mk3’s clock source should be set to Dig (“digital audio input”) when it is being used as a D/A converter. However, these settings may be changed under some circumstances. In this example, the 2408mk3 is set to receive digital audio at 44.1 kHz, and the transmitting device is the master clock source.
- Connect the ADAT optical output of another device to the 2408mk3’s Bank A optical input.