SM57 - The standard, but no longer the best. Advantages - if you see a loose screw or nail and don't have a hammer, you can beat it back into place with a 57 and the 57 will work. Disadvantages - you really have to move it around a lot to get the sound you want - which is hard if you're doing it by yourself.
E609 - The NEW 57 for miking guitar amps. Just....better, and less finicky about placement, hangs down for side address. Try it! Disadvantages - none, except if you have a metal grille on your amp and you hang it, you'll be wondering what all those annoying "tick" sounds are as the mike bounces off the grille repeatedly.
I agree with a lot of what you posted Terry.
The Hotplate is more of an attenuator, not a speaker sim. The Red Box isn't the be all, end all of emulators, but certainly beats nothing at all. Haven't tried a Mother Load yet, so no comments on that. The Palmer is actually pretty good - I don't own one, but a client does, and I've used it (although blended with microphones on cabs; IOW, not exclusively) several times. Yes, THD Yellowjackets are (usually) going to knock your wattage down a bit (although not really in a 6V6 amp), but are more about a tonal change IMO - EL84's sound quite a bit different from 6L6's / 6V6's / and even EL34's.
But I do disagree regarding the E609 vs the SM57.
I find the 609 is far more placement sensitive than the SM57. It has a tighter polar pattern, and IMO doesn't sound very good off-axis. Yes, you can hang the cable over the amp and have it sit flat against the grille, and I wouldn't mind that live, but in the studio, I'd rather avoid the direct coupling if I can - I usually don't like to have my microphones and cables in contact with my sound sources. I use mine on a stand... and I might have it only a few whisker's distance from the grille, but I never have it touching it, regardless of what it's made of. I'm just funny that way I guess.
I think the E609 is a nice microphone, but to my ears, it's a bit fuller and darker, and has a more pronounced sounding proximity effect and less presence peak than a 57. If you want extra meat and thump, it works well, and while I do own one, and have been happy with it in some cases and for some sounds, I usually prefer a 421 if I'm going for that sort of a tone.
A 57 also isn't a bad mic, but it's not my go-to on guitar cabs either. A lot of the time, for dynamics, I use Audix D2's and i5's. They have some of the meat of the 609, and some of the presence of the 57 IMO. Lately for me though, it's been more about ribbon microphones - a Groove Tubes Velo-8 on one amp / cab, and a Beyer M160 on another cab in a second room, with maybe a LD condenser further back in the room on the same cab as the Velo-8. Both of those ribbons are VERY cool sounding on guitar cabs, and both are less expensive than the (also very nice ) Royers and Coles ribbon microphones. AEA also makes some killer ribbons. I'm not too up to date on some of the Asian built ribbon mikes...
But hey - I think it ought to be possible to get at least pretty decent / good tracks with any of the microphones we talked about in this thread. I think the key is getting the guitar to sound great coming out of the amp, and then experimenting so you know the way the mic sounds and how it reacts in different positions relative to the speaker(s), and then placing (or moving) the thing until what you hear coming out of the CR speakers is as close as possible to the way it sounded out in the room.
And I agree - it can be hard to get tones without an assistant to help with positioning the mic while you listen in the control room - although a pair of the Extreme Isolation headphones can help a lot with that.
There are a ton of viable ways to mic up guitar cabinets, and I've been thinking about them a lot lately - even more than usual (and not a week goes by where I don't stick a mic in front of a guitar cab - or several guitar cabs
) because I have been getting ready to draw up an outline for a instructional video on the subject that I was asked if I might be interested in doing...
I think that might be a fun / interesting project.
I'd watch it!!
Cheers for the replies guys, really helped. Going to record hopefully next week so I should get a few previews of what I've taken on board and tell me what you think!