Several variables contribute to the quality of audio digitization. Ideally, the preamps, A/D converters, and clock can each be tested independently. Below are histograms and measurements illustrating differences in clock jitter distribution between a MOTU Traveler, RME FireFace 800, and Apogee AD-16x. Clocks were measured on Agilent test equipment using the word clock out BNC connectors. Each device was set to 96 khz sample rate. These measurements only tell part of the story about the differences in the units' resultant audio, but are provided for others who are evaluating their signal chains.

MOTU Traveler



Mean: 96.006734 kHz
Min: 95.972800 kHz
Max: 96.028972 kHz
Range: 56.1716492 Hz
Std Deviation: 4.95723840 Hz
Num Measurements: 45.682 k



RME FireFace 800



Mean: 96.000117 kHz
Min: 95.973239 kHz
Max: 96.008292 kHz
Range: 35.0523463 Hz
Std Deviation: 2.44256624 Hz
Num Measurements: 190.76 k



Apogee AD-16x



Mean: 95.999820 kHz
Min: 95.973095 kHz
Max: 96.005625 kHz
Range: 32.5304321 Hz
Std Deviation: 1.71723868 Hz
Num Measurements: 64.758 k