rpgroman wrote:

KaiS wrote:

As the listening level is probably lower, the speakers (and your ears!) work more linear, more precise.

Usually there is an SPL loudness “sweet spot” giving maximum perceived transparency.
Unfortunately this level is above what’s healthy for continuous listening.

And watch out, the switching between reference levels works with mechanical relays that produce a momentary click, that may be misinterpreted as sound change.
I fell into this trap once, thinking the reference levels produce different sound.

KaiS.....Would there be any actual technical advantage to, with auto ref level ON, having the gain setting on my amplifier such that the ADI-2 DAC operates at normal listening levels (depends on the recordings) in, say, a range of 0 to -8 db vs. an amp gain setting where the range of  normal listening volumes on the ADI-2 DAC is from -12 to -20 db?

I have some variable attenuators (-10, -20, -30) so I can play with various combinations of amp gain, attenuator settings, and ADI-2 dac volume settings.

With Auto Reference Level “On” ADI-2 DAC’s volume range between -21 to +2,5 dbr has the same technical quality / dynamic range, within 3 dB.

This is what Auto Reference Level is made for, get the maximum out of the DAC chip even when using “Digital Volume Control” - which in fact is a clever combination of digital control and analog switching.

Let me just point to my setup guide again:
https://forum.rme-audio.de/viewtopic.ph … 21#p161721
Perfect if you already have the passive attenuators to fit your poweramp’s sensitivity!