My current units
Any of my treble boosters work for any Queen song but to be historically accurate:
Galileo uses a silicon transistor (BC108) and covers Queen I.
Figaro and the Orange Label Replica use silicon transistors (BC549/BC149) and covers from Queen II to Innuendo.
Magnifico uses a silicon transistor (BC182) and covers Brian May solo career.
Rangemaster Mod uses a germanium transistor (Mullard OC44) with positive voltage and covers Queen I.
Which treble booster was used for each Queen album
Queen (1973)
Brian used an original 1960s Dallas Rangemaster. It was lost after a concert gig. The Rangemaster uses an OC44 germanium transistor and distorts more easily and aggressively than later silicon boosters because germanium transistors have lower headroom.
Queen II (1974), Sheer Heart Attack (1974), and A Night at the Opera (1975)
John "Deacy" Deacon and Brian's father, Harold May, stepped in to build a custom replacement. Compared to the Dallas Rangemaster, this unit offered more mids and defined tracks like "Bohemian Rhapsody". This DIY replacement used a BC149 silicon transistor that went through different modifications and was an early version of the "Orange Label" treble booster.
A Day at the Races (1976) through to Innuendo (1991)
Pete Cornish built different iterations of an improved treble booster based on the Deacon-May DIY. One of the iterations of this stage resulted in the "Orange Label" treble booster, which is commercialized as the Cornish TB83 treble booster. It is smoother, less noisy, and with a fatter tone than previous gear. Later units of this stage used a BC549 silicon transistor and it defined the sound of News of the World and Jazz.
Brian May solo career
Though not used on original Queen albums, luthier Greg Fryer built several strap mounted treble boosters that resulted in the Fryer Touring treble booster. Brian has used these for recent Queen + Adam Lambert tours and solo projects.
References
Brian May Guitars Treble Booster Classic
History of the Brian May/Fryer treble boosters and other Greg Fryer pedals made from 1997 to 2022