The Symphony Desktop's optical inputs has an automatic and transparent Sample-Rate Conversion feature built in. When a digital audio signal arrives at the Optical Input, it is converted to the Symphony Desktop's internal sample rate. This works for any sample rate between 44.1k and 96k.
- Symphony Desktop is set to 96k Internal clock.
- A CD player is set to 44.1k internal clock.
Simply connect the CD player's optical output to the Symphony Desktop's optical input, and Symphony Desktop will convert the input signal to 96k sample rate with no change in pitch, speed, or tone.
NOTE: Symphony Desktop will not automatically change between ADAT/SMUX and SPDIF protocols. You must manually set Symphony Desktop to match the protocol of the device sending the optical audio signal.
If you need bi-directional signal to your external gear where you will also be using the Symphony Desktop's optical out, then the external gear will need to follow the traditional master/slave clocking relationship and be set to External clock via Optical, as well as match the Symphony Desktop's sample rate.
The Sample Rate Conversion feature is in place because a USB Audio Interface must always be the master clocking device.