Its a great sound, great enough to obsessively collect different versions, but man does not live by vox alone! Well, sometimes this man does. But verily is it said, he who loveth the muff and the righteous punch of the 800 cannot long prosper with just the finicky top boost channel and ultra compresed Vox power section...
honestly, you would probably LOVE a late 60s AC50 (a mk3 or mk4 is somewhere between your 800 breaking glass sound and an ac30), but they are thin on the ground anywhere but England and Scotland, still relatively affordable vintage amps though... if you can find one they're a good value with just a little more headroom, punch and note definition than the ac30.... the earlier ones are more desirable but stock they have less gain and won't break up until they're LOUD, like a proto-hiwatt.
why don't you just buy an ac15 or ac30 and get a less scooped fuzz/distortion that's still in the big muff camp? Even the big muff with tone wicker might do it into an ac30 topboost channel with the tone wicker, ummm, wicking.... swollen pickle mk2 is a muff variant with adjustable mids.... proco rat and its variants and clones can get fuzzy/muffy at the top end but it has the mids though its light on bass (another thing the ac30 gets picky with), and you can buy into rat for peanuts with the Mooer mini version. Everyone loves that. You might want to just rethink a little. The muff is the be all, end all. Its just the first thing of its kind.
I have spoken, Terry shall buy a used ac30 or ac15 handwired and trade his big muff in for something more versatile unless he can find a recently serviced AC50 mk 3 or 4 for about 1k AUD. He should also find someone with a 50 watt JCM800 2204 who wants a 2203 instead (because that guy is now playing stadiums or contracted to use his guitar sound for enhanced interrogations at Guantanamo) and swap with that guy. So let it be written, so let it be done.
thread hijack over