which gain setting for Bryston 4b cubed power amp using my RME ADI-2 DAC FS?

the amp has two gain settings, 23db and 29 db.....the manual suggests 23db for balanced sources....not sure if my RME is balanced despite its xlr outputs

does 23db mean lower noise but also less power output?  can I just try both settings or could the wrong one be harmful?

please and thanks

I've pasted below the manual info around this piece

"Gain Select Switch:the optimum gain setting will depend upon the
source pre-amp operating level, and or personal
preference.

The 29dB setting is used when the source is

single-ended or from a transformer coupled
balanced source. This is the typical for single
ended or un-balanced operation. The 29dB
setting provides the most amplifier gain and
equates to 100w @ 8 ohms output for a 1V input.
The 23dB setting is used when the source
output is actively balanced. This is the typical
setting for balanced operation. Or use this
setting whenever less gain is required. The 23dB
setting equates to an output of 100w @ 8 ohms
for 2V input.
The noise is referenced in dB below rated
output. Different input configurations result
in slightly different noise readings. The above
noise ratings represent minimum readings.
Actual readings may be better.