I advocate playing around and experimenting. I have ended up with a lot of gain coming out of the preamp with the gain/volume reduced on the amp. In my systems thsi brings body and texture to the overall sound and suits my rooms and tastes. A very different presentation can be summoned by reversing that method. And gradations in between the two methods.

Sounds to me like the Torii gain may be set too high for the gain levels you are trying to achieve from your pre?

Right now, I use a Zstage, then a CSP3 and Torii IV, and am definitely an advocate for adjusting the pre-stage voltages going into the amp for optimal sound, and not using the pres as volume controls... more voltage from your Aric pre will very likely feed the amp a more pronounced signal... Like Lon and Dom suggested, that sounding different depending on settings, the signal bigger and more intense, or leaner and less intense.

For me, in the optimal range, the signal the amp gets from my pre has more lucidity, more visceral clarity, greater dynamics (macro and micro), more density and weight.... But not over the top in any of these areas.... where all these can be taken too far with the pre set too high .... the signal becoming too dense, too punchy, too in your face, too dark and weighty. So I go for a balance that is more lucid (compared to just the amp), enhancing density, dynamics and clarity while also enhancing fine detail and space. The pre set too strong, the sound can become impressively dense and dynamic, but also can tend to concentrate the natural harmonic musical characters too much, signal density overwhelming inner detail, micro detail and space, and thus, in effect, masking subtleties of air, textures, and decays.

I think it is better to imagine it as "riding the gain s," where we find a balance between the pre and amp for favorite listening volumes, that balance making the system sound best whether the volume is achieved with more on the amp gain setting or by more on the pre setting. One thing for me that got me into gain riding, was that my amp tends to maintain similar qualities within a good listening volume range, whereas, my pre stages change the signal sound and volume. So I tend to use the amp as the primary volume control. But when listening in my optimal volume range, changing recordings, I use both for minor volume changes depending on what recordings I am playing... fine tuning the sound to denser and more powerful with the pre up a little for lean or less dynamic recordings, and the pre down a little and the amp up a little for recordings that are too dark and full.

I have had problems with distortion using the ZRock2 and ZStage, especially with more than one pre stage in sequence and while using higher power input tubes in one of them. Not clear on just why. I can enjoy sound qualities of some 12AT7s (in the right company), but to avoid distortions with the gains balanced in ways I prefer for more obvious sound qualities and nuances, I need the more relaxed 12AU7s in these small boxes, or perhaps a tube in between 12AU7s and 12AT7s, like E180CC in one of them. In my setting 12AU7s are more reliable for avoiding early distortions in the Torii.

I wonder which Aric pre you have? On a quick perusal, I noticed some have an additional gain adjuster... another potential way to optimize tube/pre sound while toning that adjusted signal down or up with what looks like an output gain adjuster.