I now have the 4215/E2 in a very nice setup with the Eversolo A6 master edition with linear PSU fitted with USB in to RME ADI2 DAC also with linear PSU and finally connected to my triangle BR08 speakers. this sounds awesome and the 4215 sounds wonderful via Qobuz
For the people who believe you can just use cheap connecting cables i have listened to the difference and can hear it. this goes for XLR and usb cables. I use the BoXem XLR cables from RME AD12 DAC to amp and a high grade USB cable from eversolo AD6 to DAC. the quality of the cables can make a difference you can hear.
have a look here
This 4215 amp sounds great so don't skimp on the cables, they are worth it.