To my personal taste - admittedly biased towards warm-than-neutral tunings - the Immanis still needs an amp that tames down their treble energy and reinforces the upper bass / lower midrange, not so much differently to when I had the SR1a and did a long list of auditions to find a good matching amp and/or EQ. With the AIC-10 and the Mullard tube I am close, but not yet there, so as I am not willing to replace the Riviera anytime soon I may need to resort to EQ. Anyway, I will wait for my new DAC and several more hours of experience before moving ahead with this.
The CA-1a with coffee-been pads on the VM-1a (triode mode) with some aptly selected vintage tubes had both fuller body and smoother top end, and was actually overall more aligned to my tonal balance personal tastes than the Immanis. However, it could not match the Immanis bigger and deeper soundstage, resolution, speed, clarity and overall out-of-the-head experience.
The deep reach of the bass combined with the shockingly fast transients are a blast, with some recordings.
It's been a while since my last listening of this album, but yesterday I stumbled into it with the Immanis and it made me laugh out loud.