Roland M-1000 Owner's Manual page 29

Caution: About Digital Audio Input/Output
The Digital IN connectors of M-1000 are compatible
with 2ch PCM audio only. In case M-1000 receives
audio signal in other formats (DTS, Dolby Surround
etc.), it outputs such signal as noise.
M-1000 does not have any multi-channel digital audio
encoding function such as the DTS format. And do
not input DTS signals or any other this kind of signals
to the digital input on M-1000. If you input DTS
signals to the digital input on M-1000, they cannot be
decoded into multi-channel signals. Please use an
external encode/decode device.