Passive Preamp for Atmaspheres?

Disclaimer, I work with Superphon preamps...that said, Superphon preamps by Stan Warren are available with or without gain, active super clean sounding preamp... might want to look in to these here on Audiogon Rev III model is the current and best version now being handmade made after extensive research and testing by Stan Warren. I would check the parameters the amp manufacturer sayd his amps want to see from the preamp to make sure ahead of time you have the correct match. Superphon.com
Best with the music...

The closest I can come to shedding light on your inquiry is to note that a friend of mine used to run M60s via the built-in volume control of his Wadia 861 into Merlins with good results IMHO. Almost all of his repertoire consisted of jazz and small ensemble music. I don't know how electronica or bass heavy music would fare but my impression is that it survive mostly intact. I personally run M60s partnered with an MP-1 and find it transparent enough that I don't have the urge to unplug it. Of course, an MP-1 is a major financial commitment relative to just about any passive. I myself am curious as to what others will share here.

I use the Scott Endler attenuators with my M60s, when I'm using a fixed output CD player.

If your run isn't too long, and your only source is the Arcam, you may well want to try these as well. Even if you decide to use additional sources, such as a tuner, I still think a passive preamp can be a good way to go. When I use the variable output tube section of my CDP, I don't use the attenuators at all.

You do gain a little by going into the Atmas via a balanced cable in terms of a lower noise floor. So, regardless of whether you go with an active or passive preamp, or direct, having XLR connectors on one end of the cable allows you to take advantage of that.

In my experience, I have not tried the AtmaSphere preamps (maybe I should?), but none of the other highly regarded units I tried ever came close to not having a preamp in the system. Worst of all is when a preamp imposes its signature so strongly that much of the OTL magic in the Atmas was hidden to a great degree.

maybe buy a Quad or similar CD player with volume control and save on cables and pre amp etc...

I hadn't heard about those Scott Endler attenuators. I was considering the more expensive, nude ultimate attenuators, but The Endler's seem to get great reviews and at $160/pr. I just about have to try them out.

All responses greatly appreciated. After I receive the new gear, I'll report back with some results.