What DACs support DSD input NOT via USB?

I think the Elgar fits your description.

Any chord Dac...though they convert internally to PCM.
Qute EX, Hugo, 2Qute, etc.

Mytek with Firewire.

I think also the BMC Pure Dac can use Optical and Coax. The real problem here is the Transport. How to get a DSD stream which must come from a PC or streamer/server via Coax. DoP would be the likely only way.

I don't think DSD over PCM is supported on most DSD DACs via the SPDIF inputs. If they are, they are limited to 24/192 which means you can only pack DSD1x max even if the DAC supports DSD2x or higher.

I know for a fact the PS Audio DirectStream does accept DSD over PCM via AES, SPDIF, optical as well as USB.

However, getting DSD over PCM via SPDIF is much harder that you think.

The optical and coax out from your Oppo does not support DOP protocols.

In fact, play SACDs and those digital outputs are disabled. Also, copy protected BluRay PureAudio/movie soundtracks are down sampled to 48kHz when sent via SPDIF.

The only way to get DSD out from the Oppo is via HDMI. You need to set the Oppo to send out DSD natively. This is meant to be used normally with an AV receiver with DSD compatibility - but obviously these aren't usually built with the same care and attention on the analog/DAC modules.

So this means you may want to consider:
a. a Bryston BDA-3
It is a Bryston 2 channel DAC but it has HDMI inputs that can take DSD, along with a more conventional DSD capable USB input

b. modify your Oppo 103 with a Vanity Praise digital output board.
This works by intercepting the HDMI audio output - and converts it to SPDIF and DOP.

Take a look at the upcoming NADAC (Network Attached Digital to Analog Converter) models. Comes in 2-Channel and 8-Channel and does not use USB at all - only Ethernet.

http://nadac.merging.com/

My dCS Debussi does. I think most if not all dCS products supports DSD over AES/EBU & USB and more types will come.

Dartzeel LHC-208...combo 200wpc Class A/B Integrated amp and Ethernet Dac. Plays straight from the NAS.

I think the PS Audio DirectStream DAC does.

Neal