There are many variants of this at large on the Internet but I haven’t found one that worked particularly well for 1980s era and later Queen nor one that actually works well with a Brian May type guitar.
Many of the tones use the Helix’s Essex 30 model which is actually a simulator of the Top Boost Circuit when Brian uses amps reduced to the Normal Channel.
Similarly, there is no dedicated treble booster in the Helix though the KWB Distortion which came in a recent update does a very passable impression.
Finally, Brian May’s stage sound is the result of three amps with two panned handling the effects (chorus and delay) and another unaffected.
This tone follows that scheme virtually.
Check out my video below to hear it in action or click to button to download it from customtone.com
I put in some extra features, a harmonizer (set to A Major) with two voices, a 4th and 6th below pitch and two delays (set to 800ms and 1600ms) like Brian’s.
There’s still room for improvement so if you’ve any thoughts on how to improve it please let me know.
I’ll keep updating it here and on customtone.com.