Volume level of ARC Ref 5 seems very high

Thanks Doggie . . . please remind me. Did you do the SE upgrade on your "old" Ref 5, or just buy the Ref 5 SE new? If the former, then I appreciate the heads up re expectations. If the later, I wonder out loud whether I will get any break-in "benefit" because the rest of my Ref 5's innards are well broken-in by now.

I live outside the US so my dealer got me a new unit and handled the upgrade on his own.

doggie, thanks a lot for the feedback on the Rothwells. I'll surely get myself a pair to see what they do to my system on this side of the globe.
are you using balanced or SE cables between your CDP and Ref5 SE?
can you tell me what is the sound pressure in db and at what distance from the speakers that you experience at the 35-40 level?
regards from a white Paris.

I noticed that while the SPL with the Rothwells in and the ARC at 35 was about 70-78dB for one of the pieces I was listening to, and w/o the Rothwells, the SPL was ard the same level when the ARC was at 25, there was a tactile feedback I was getting with the Rothwells in place. I think that's the transient/dynamics part of it at play.

My speakers are about 8 feet apart and I sit about 8 feet away.

I use XLR (ASI Liveline) from XDS1 to pre and XLR (Silversmith Silver) from pre to power.

I see you have a similar situation as me, high efficiency loudspeaker matched with a: 2 volt output preamp, and a 500mv input sensitivity amplifier. If you find the attenuator route degrades the sonic qualities (I can't imagine it not) the other answer is the find a better match with the input / output relationship. Right now your preamp at 1/4 power is driving your amp to full power.