I use the ADI2 DAC FS with a power amplifier by adjusting the volume on the ADI2 DAC FS.I don't know which fixed level +1 dBu, +7 dBu, +13 dBu, +19 dBu to choose for the best qualities!!!
1st, There is no +19dBu, highest is +13dBu, that 6dBu difference is at the XLR output, XLR output always deliver 6dBu more than the RCA output.
2nd, decide which input of your Amp you want, RCA or XLR? check the manual of your Amp about the input level, if not available, assume RCA input is 2 volts, that equals to 8.23dBu, set it at 8dBu is safe and offer some headroom for Bass and Treble as well as Loudness. it is the same as in XLR input.
This link is a very good reference for you. https://forum.rme-audio.de/viewtopic.ph … 21#p161721
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