My pleasure. I'd absolutely demo the bursons with your own headphones if you have a shop that stocks them. I went for the X, balanced version, because My Cambridge Audio 840C CD player and Rotel RB1080 200wpc Power Amp all have balanced connectors, and for connecting components balanced is an advantage in rejecting noise. But as a headphone amp Andrew Sparko says this in the review linked below:Thanks for your input
Q2: It is clear that Aries targets the ones that are looking only for the best headphone amps out there. Is there a reason you didn’t feel making it a true balanced amplifier with a 4-pin XLR jack on the face plate?
SparkoS Labs: Yes. The design is single ended, so we didn’t want to mislead anyone by putting an XLR output jack which may give the impression that it was balanced when it isn’t. Balanced designs are good when the power supply voltage is limited (such as in car audio) but this was not the case in the Aries since its powered from the AC line. Balanced designs also have 3dB more noise and require 4 amplifiers (two per channel) which would increase costs.
He has 2 versions, a single ended headphone amp US$2500 and a single ended headamp and balanced preampUS$3000