Re: What's the best way to get early-mid 70's classic crunch.
Find a 1987X reissue and grab a 1x12/2x12 cab. It's based on a 1972 circuit and it will SCREAM. Or purr, or do a heck of a cool Marshall clean. When I had my Heritage w/ 59's I never had been closer to those great 70's LP/Marshall sounds...page, gibbons, kossoff, etc. And goosed with a Tubescreamer it was 80's metal meltdown (LOL..sounds like one of those cheesy compilation CDs).
Word of warning though..they NEED to be cranked, and they are LOUD. Buy a hotplate/power brake.
IMO, as much as Marshall would like you to think the newer amps can get that sound, they really cannot..at least without being modded. Non MV amps have a character all their own.
And I'm not saying this because mine is for sale, LOL. It's the truth. The TSL/DSLs cannot do it. The 900's couldn't. The JTM/JCM 600s could not, nor could the 800s or JMP MV amps. Sure they can do a good classic type crunch, but it's not "right".I've played through older (late 60s/early 70s) non MV 50's and 100s and they all have THAT sound (to a certain extent, they all varied a little sound-wise).
For other brands I'd look into maybe a Peavey Classic 30/50 with some mods (new tubes, speakers), or a Traynor.