@hiend2
I have mine connected with both I2s and Aes and switch from one to the other with my gustard remote depending on recordings. If opening up the highs is your objective, the I2s connection is the way to go. However I prefer the more solid sound of the Aes for hard/metal recordings which also provides a bit more width in soundstage to my ears. Also I recommend the Qstab CD clamp which will somehow provide an airier sound with more space around each musician. However, for you to talk about the sound being MUTED in the highs makes me think something doesn't compute. Brand new out of the box the Jay's was a huge step up in treble clarity from the Cambridge CXC. But I use a Gustard x26 pro, not the r2r Pontus. I never used the RCA connection but I would venture to say you are not doing yourself a favor if you can use Aes or I2s, both likely much superior to rca.
