How to get a warmer sound?

[DRONE7]

It could be that the DAC's USB chipset is not compatible with Linux USB audio driver. Does the DAC manufacturer officially support Linux?

If it's not a compatibility issue then it's not obvious to me what might be going on.

From their literature they support Mac and Windows....no mention of Linux.

and...perhaps this has some bearing...

Its Burr-Brown converter chips, for instance, are also found in our flagship CD555 CD player. The DAC overcomes the jitter inherent in standard digital connections by reading data independent of its timing signal. Its digital filtering, based on a 40bit floating-point SHARC DSP chip running unique Naim Audio code, sets new standards in its class