I have connected my pro via RCA to the FOSI ZA3 no external dac.I find the sound volume low and lacking bass and detail .You turn need to turn the volume past 12 o'clock to get any real volume. When I connect my phono preamp to the same input it's night and day difference compared to the WIIm .I have the pros volume all the way up as well.Is there anything I can do to fix the issue?