Actual Rega Osiris owners

There is no "readout " as COURANT as already succinctly highlighted above.
Indeed its just a simple continuous rotary dial with no markings, with the implied analogue "clock" volume position as your reference point. The ultra- heavyweight machined remote is delightful,

I generally play mine at a usual setting of "9 o’clock - 10 o’clock" for normal critical listening when I am alone,  that still generates all the necessary dynamics and slam comfortably preserved. The efficiency of your speakers will be a determining factor. 

The volume level gets easily and linearly scaled back to a lower volume position when conversation is involved. .

At a 12 o’clock volume position, it’s actually uncomfortably loud in my system requiring a significant immediate scale-back . I’ve never had a reason to have it cranked up there, much less past there.

I’ve had my OSIRIS for 4+ years now and it’s a fine performing unit that is built like a tank (it is about 55 lbs in weight.....) with gobs of surplus power .

The volume control is a continuous radial pot. You set the volume by turning the pot to the desired "clock position" volume level, like on a NAIM SN2. There are no readouts other than the "clock" position of the pot. When I owned an Osiris (more like a test-drive) I would typically set the volume to what I thought was a moderate level: 10 to 11 O'Clock. 12 O'Clock was LOUD; 3 O'Clock was INSANITY.

FWIW, I ended up not keeping the Osiris when I read-up that it was prone to servicing. The owner of the shop I got it from also owned an Osiris for a while, and sold it after sending to Rega to service for the 3rd time. I really liked the sound, but wanted something more dependable. Hope that helps.

I'm confused by your reply as it doesn't really address my questions.
Since you own the Osiris.
1) what type of volume control is it? Continuous or stepped ? 
    If stepped what are the steps  ( 1, .5 db etc.)

2) what does the readout show when volume is changed? Does it indicate %, db or what?

Please elaborate.

Without prejudice to the following blurb,

(1) I have the REGA OSIRIS integrated amp sourced by the REGA ISIS VALVE cdp, so I know its saga very well. It’s specs highlight the following: "’...with a passive volume control (an Alps Blue Velvet potentiometer is used)..."

(2) What is the concern about "stepped " versus "continually variable " ? Anecdotally, its "ultra smooth" and analogous to a simple continuous"straight line " operation.

 I will defer to the techno geeks to explain this approach in detail. (Techno babble to me)....)