Hey Joe,
Good question. I have a single rec head also but mine is an old V1 and doesn't sport the Raw mode. I don't know the answer, but if you're taking bets, put me down for two bucks on "2 gain stages". Something else I wonder about is whether chan 2 uses four stages in vintage AND modern, or three in vintage and four in modern.
Not to be nosy, but why do you want to know? Planning some mods? Have you ever thrown Yellowjackets in it and tried it with EL84s? Ever throw a Bottle Rocket or other OD in front of it? Did you like it? What time is it? Is there any pie left? What time does Zorro come on? :shock:
I like the single rec head. I use it through a Road King 4x12 cab when I do heavy rock and metal rhythm parts. It'll pop light bulbs.
M