After my recent bad experience with a MOTU 828mk3 interface, I bought a Focusrite Liquid Saffire 56 interface .
The first thing I tested when I got it was its SPDIF digital output against my Yamaha RX-V2500 receiver's digital input . Fortunately, that worked just fine, all the way to 192 kHz using an optical cable.
I then hooked up my ART DPS II digital preamp to the Saffire's digital input via SPDIF .
Everything worked beautifully at 44.1 kHz and 48 kHz . But when I tried at 88.2 and 96 kHz, the audio transferred from the ART to the Focusrite was garbage. I tried both optical and coax SPDIF cables. I tried different clocking configurations - making either the Focusrite a clock slave to the ART via SPDIF, or making the ART a clock slave to the Focusrite via a BNC word clock cable. Neither helped with the transfer of audio at 96 kHz.
I knew the ART unit was not at fault, because I can transfer data from it to my Roland VS-2400CD DAW over SPDIF at 96 kHz just fine.
I contacted Focusrite about this issue. They got back to me promptly, but were not an aware of existing problem. They suggested I exchange my Saffire 56 unit for another one to rule out a defective one. I did not get a chance to do that as my local Guitar Center did not have another one in stock for me to try.
Because of this issue, I ended up returning my Focusrite Saffire Liquid 56 to Guitar Center for a refund.
Even after this return, I have remained in touch with Focusrite . Their UK team said they are in the process of obtaining an ART unit to reproduce the problem. If they are able to do so and fix it, I will purchase it again, provided I haven't found something else that works in the meantime.
Somehow, everything else I have tried has had problems so far, unfortunately.