i cant really say they were amps used by much of anyone but the few folks i knew out in western pennsylvania in the late 80s and early 90s. :lol: but i bought mine full of telefunkens in 1992 for $400. you saw a lot more of the earlier protubes than aors, and i dont think i ever met anyone else with one like mine! still never had an amp that went into singing feedback anywhere near as well.