to equalize the vinyl and digital source volumes, you might try moving the dac8 dsd analog out slide switch to "VRLB" from "FIXED" and then use the volume controls as a means of lowering the output level to be more in line with that of your vinyl.
i have not noticed any SQ impact of using the VRBL setting on the few occasions i have tried it.
i have not noticed any SQ impact of using the VRBL setting on the few occasions i have tried it.