Which Would You Choose?

You speakers are in an entirely different class to the rest of your equipment and you probably need to think of upgrading almost everything not just a power amp.  Actually IMHO your power amp is the last thing you need to replace.

Your room

@mazian

+1

I must admit, @mazian is correct. Your Olympica are capable of way better sound. But they need to be feed with electronics a couple levels up.

I used to own Olympica 3s for many years. I supplied them with a $18K DAC / CD player, Audio Research 5SE preamp, and Pass 350 amp. While a great combo, if I had switched to a ARC Ref 75, they would have sounded better.

Ideally a preamp like a used Audio Research 5ish, Amp like Audio Research Ref 75, or Pass 250 would kick your system up a level or two.

Rotel and MoFi is midfield stuff… your speakers are way better than that.

I would start by getting an audiophile preamp. Look to Audio Research, Presto, Conrad Johnson, or VAC. I would look to spend around $8K.

Given your speakers an appropriate allocation would be Streamer, DAC, preamp, amp each cost (carefullly chosen and synergistic) = ~$8K. This will get you the very best sound out of the Olympica.

Hegel New H 600 is far better then both.

Tube amps too weak on the bass drivers the Hegel has a class leading

4000 damping factor which is far better then. The competition by a large margin,

giving far better control and slam to all drivers.  And the Hegel H600 

has a excellent preamp section to complement the Dual mono amplifier section 

and a very good dac section even better streamer that has tidal but will have Roon to add very soon with QObuz and other software upgrades. Substantially better then any previous product far closer to their best separates. I am considering this for myself.