[Slowhand] the "Beano" sound (gearhead question)

[bluesman13]

I read recently that there is a rumor that Clapton used a Dallas Rangemaster (treble/tone booster) in addition to his Les Paul and Marshall to achieve his legendary sound on the Beano album. I hadn't heard this before - but in a way it makes sense because of the active circuitry on his sig strat - they seem to be similar.  I found a couple of websites that talk about his use of the Rangemaster,  and since the Rangemaster isn't a stomp box, it would have to have been sitting on top of Claptons amp. I haven't seen any pictures from the Beano sessions that show it, so I'm a bit skeptical.  Anyone have any thoughts on this?