Good review slim.a. Thorough as always.
I just want to add that since getting rid of my Oyaide DR-510 and getting a new coax cable, the transient response, low-level detail, and soundstage all improved noticeably. The Oyaide's smooth/rounded and relatively slow sound doesn't mate so well with the already slightly soft-sounding jkeny HiFace IMO.
Regarding the digital cable, I didn't explicitely mention it on the review but I listened to all the converters with at least 2 digital cables:
- The 1.3m Oyaide DB-510: my reference cable, which you are already familiar with,
- And the 1m Hi-fi Cables & Cie Sobek: my former reference cable, which is a high performance BNC cable that uses silver plated copper (with Teflon PTFE insulation) and multiple level of shielding (Silver plated copper screen, µ-Metal Permalloy, Polyimide Kapton R)
My comments about how the units compare to each other are the same regardless of the digital cable being used.
I admit that the Sobek has more treble sparkle than the Oyaide. However, whenever I play some high quality recordings containaing unamplified instruments that are difficult to render (such as violins, pianos, glass harmonica), the Oyaide seem to get the upper hand. It is the only one to offer me distortion free treble and the necessary refinement and information in the upper harmonics.
Or in other words, when the high frequency information is simple, the Sobek seems to have more treble energy and when the high frequency information is complex, the Oyaide seems to have both more treble energy and less distortion. This is at least how I hear it in my system.
BTW, Pacha has had the opportunity to listen a little while ago to my system which was using the modified Hiface + Oyaide and I don't believe he found the system slow. But I would rather let him comment on that.
At the meantime, you are right, pairing the smooth Oyaide with the slightly soft sounding Jkeny's Hiface is not and ideal recommendation in most cases (while the stock Hiface + Oyaide was a very good match).
That is why I am currently preferring the Digital Interface (w/ upsampling to 96K) + Oyaide.
Downsize's digital cable you are using seems intriguing (and promising) and I might try it in the future.