@williampowell yes, your Parsec and Iridium are going to be a bit laid back/warmer/grainier sounding in comparison to Cygnus. They are different cable designs too. You can send an email to Cardas and Josh or Brian will explain differences with Cardas 1 or 2 copper and the 2-wire vs. 4-wire conductor layouts too. I’ve owned both and they are different, having tested both 2 and 4 wire designs and versions.
Is your Classic 120 amp the standard version with EL34 output tubes or the SE version with KT120 output tubes in it? If you are running the EL34s, missing some of the upper detail now, and had to choose, i’d likely suggest Cygnus over Parsec to pick up some of that upper register you are looking for as one option. If you choose to keep your EL34s, maybe call CJ (first) and ask if there are other coupling caps you can run in your Classic 120 to pick up some more detail, another option. Before any of these, you might ask them about trying other 6922 tubes to get closer, and its a less expensive option to try. This may not give you the Cygnus 3D affect and total upper register detail (and air) you are looking for though. Finding the right match of tubes / interconnects / speaker cables makes a difference to fine tune it a little more to your taste. Best of Luck.