I've seen a lot of threads discussing what mic works best to record an amp. I've been using a SM57 close up and a AKG BLU/S 414 to get a bit of the room. They're both solid performers, well known, predictable and reliable. The biggest difference I've heard is not in mics. I've tried some more expensive mics (borrowed)...a bit better but not a dramatic difference. But when I upgraded preamps...WOW! So much more articulate, larger and more 3-D. Previously I had used the pres on my Mackie 1404 VLZ-Pro and an Aphex 207 and Aphex 107 pres. Lesson learned...low end tube pres are just gimmicks. They were nice cheap pres, but I never heard the tube warmth. The Mackies were good, but nothing special. When I got a Great River and Langavin Dual mono, the guitar sounds just started jumping out. I choose those since I couldn't affored a real tube pre. So I got the best solid state class A (they are class A aren't they) pres I could afford. Better one good pre and one good mic then a bunch of lesser stuff.