I am a very long term and dyed in the wool Marshall JMP 2203 user. I have also used loads of other amps (Twin, Princeton, Deluxe, Marshall 1986, Marshall 1987, Marshall 1959, JTM45, BBRI, AC30, AC30TB, Hiwatt DR103) both on their own, and in A/B/A+B setups with the 2203. However whenever I tried to get a channel switching amp that would replace the 2203, and do so with the flexibility of having a clean channel, they worked in the shop, they worked at home, they worked in the rehearsal studio, but I'd get to the first gig and it would be, "Nope, need my 2203 here". Closest contenders were Matamp [very] Custom 100, Orange RV50, and 65 Amps Whiskey (which I really did love, but it was a lot of money to have tied up in something that
nearly worked for me). When I got my Axe FX II I could get the MV Marshall sound with a LOT of deep tweaking, and by the final firmware AFX II version it was really pretty good. Finally something flexible I could gig with, and I have not taken a 2203 out since. Have been using that Brit 800 model a lot with the AFX III over the last couple of years as well.
For me, from the first of the public beta versions, Cygnus is extraordinary in that it pretty instantly nails the response of the original 2-prong Marshall Master Volume amps, warts and all. Right down to unresponsive bass control, especially when the mids are turned up, weird presence response, total character change between 3 and 4 on the master volume if using "just into crunch" preamp settings, but most importantly the way it responds to digging into the guitar dynamics. That was before it got fine-tuned, and it was the one I was waiting for, and like you say, the Brit 800 is maybe indistinguishable. It must be a quirky amp to model, because it's not a terribly well-designed circuit in conventional terms, it must have sounded pretty poor in the shop or bedroom when it first came out in 1976. But for whatever reason in a loud rehearsal or gig, when you really let the thing rip, that has been almost an addiction for me for over 25 years. It just works brilliantly in the mix of a noisy band.
Are the Marshall 2203 or 2204 a good sounding amp? Not really. Hiwatt DR103, Marshall 1959, Blackface Twin all have more conventional beauty in their tone. But like the Fender SF Deluxe Reverb, there's something very musical and usable about their inadequacy for me. It was the way that this shines through in Cygnus that made me realise something rather different is going on in the modelling now. It feels like my amp. I wish I still had my old '78 SF Deluxe Reverb to compare with Cygnus, because that was another amp that wasn't terribly beautiful sounding in conventional terms, but stick it next to a drum kit for 2 sets of Chicago influenced blues and I knew I was in for a great evening. Probably no coincidence that there is another model that for many
may seem "worse" in Cygnus. For me, this is definitely my definition of better.
I'm cheerfully soft resetting every amp block before I try it, and then having a good play with "authentic" amp knobs on anything I try now. Haven't got as far as "old, old" Marshalls or Vox AC30 yet, but for all the Marshall and Fender models I have tried so far, Cygnus just works better and more authentically than anything so far. I have questioned how much better Fractal modelling could ever get for years now. I really have to wonder if there is very much further they can take this. Could it really be time to model the Klon Centaur? I think that might be the final hurdle.
Liam