As Erik posts above, I also suggest you look at the Ayre Codex DAC priced at $1,795. "The Codex has many design features not commonly found in a DAC that retails for $1,795. One is a pure analog, linear power supply instead of the more commonly found switching power supply. Another is a custom Ayre developed Minimum Phase Filter that was developed from 4 months of listening tests with a Burr-Brown DAC chip. A fully balanced signal path throughout the analog circuitry with zero feedback is also found in the Codex". Please see these links:https://www.ayre.com/codex.htmhttps://www.ayre.com/codex_specs.htmhttp://www.audiostream.com/content/ayre-acoustics-codex-usb-dac-headphone-amp-digital-preamp#6VhR3Vj...
I am ALSO considering the Ayre Codex DAC and will use its single optical input connection. The Ayre Codex DAC has received great reviews and it is amazing this small DAC can sound so good. I will be using it as a DAC only and will not need its volume controls. Several reviews have stated the Codex DAC is very musical. In addition, its been suggested that the synergy between the Ayre Codex DAC (using balanced cables) and my Ayre AX-7e integrated amplifier is excellent. I have been told the Codex sounds "best" when its balanced output connections are used.
Based on the reviews I have seen, I suggest you should research the Ayre Codex DAC. If your ability to audition equipment is limited, please continue your research and do not rush your decision.