@soix Thanks for the recommendation of trying the shorter I2S/HDMI cable length - there was a subtle difference in favour of the shorter 1ft length vs the 2ft incumbent, though I guess if there’s such a thing as burn in for HDMI cables it might improve further. Incidentally the logic of shorter is better for I2S makes intuitive sense to me and may also help explain why the internal streamer of the R26 (and other high quality DAC/streamers) can sound very good indeed - the internal i2S connection will be extremely short - just the distance between the streamer and main DAC circuitboards essentially.
@peareye The HT DC III is an excellent cable - clearly the best one I’ve tried. HT >> LMR400 /> C2 >> Minicircuits 50ohm >> Pro audio 50 ohm > Hifi coax digital 75ohm.
Best performance/ price ratio is the LMR400 - which after a week’s burn in - and it really does take that long to sound good - it surpassed the C2 in terms of resolving power and dynamics, though the C2 was warmer and smoother so more forgiving. Downside of the LMR400 is it is really thick and rigid plastic tubing like a plastic hose so is cumbersome to use and can feel like it is putting a fair bit of lateral stress on BNC sockets.
@pinwa John Swenson certainly knows his stuff (it’s an interesting paper isn’t it) so all the best with that - should be a cost effective route to achieving a good standard for sine wave. Incidentally I’m a sine wave fan - worked best for me with the OCK 1 & 2 with the R26 with all the cables I’ve tried so far.