Listen to UFO's "Obsession" album again. IMO, thats about the best Marshall type lead tone of all time. Alot of people think Schenker filtered a wha on every solo back then. He didnt do that until his second solo album (filter damn near every solo). There are only maybe three spots on that album with a wha. 'Pack It Up and Go", no wha, "one More For the Rodeo", no wha.
Schenker used an older (68-72 ?) 50 watter on that album. It obviously had the .68uf cap over the 820 in v2, excellent upper mid/highs

That album was recorded in Los Angeles in the spring of '78.
Seems 'ol Ron Nevison may have heard VH1 by then (as well as Schenker)

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