Looking for a 2-channel high end volume control

Interesting to learn about the Muses, I've not come across that manufacturer before. Spec is very similar to the Cirrus and TI although the Muses has a gain stage built in (but not great distortion figures).
In all honesty I'm not even sure whether 99.9% of people would ever notice whether it was a pot, IC or switched attenuator. In terms of noise the ICs score lowest, pots are pretty good when they're brand new. Pots are worst on left/right tracking and longevity. And switched attenuators are either expensive and have limited steps (passive types) or expensive and complicated (log relay types). If 'high end' means best sound quality then none of the ICs really cut it... I'm only saying that because 'high end' is in the title of the thread.

Optical resistor

https://tortugaaudio.com/products/diy-preamp-components/electronic-stepped-attenuator-epot-v3-max/

I never heard of Cirrus, but there is DACT, Goldpoint, Elma, Shallco, Noble, Penny and Giles, and etc, all of which make excellent two-channel balanced attenuators in your choice of impedance. (I am sure I left out a few other quality brand names.)  Depends upon how much you want to spend.  In addition to conventional resistor-based attenuators, like those mentioned, you can also think about attenuators based on light intensity and a photo-electric cell.  (I guess that is what danager points out above; I personally would stick with resistors.) No reason to mess with an 8-channel device when you only need 2.  If you don't already know much about attenuators, you might want to spend some time familiarizing yourself with the pluses and minuses of the various types, e.g., series, shunt, or ladder type, and e.g., stepped attenuators vs continuous types, etc.

And Khozmo, which is excellent.

Optical resistor
https://tortugaaudio.com/products/diy-preamp-components/electronic-stepped-attenuator-epot-v3-max/

Haven't come across talk of LDR attenuators for a while... I could never work out what the attraction was. This one tracks about the same as a half decent pot (0.5dB ∆ L/R) but has 0.5%THD. I'd be interested to know what it is that makes them an attractive option... maybe people like the sound of the distortion?