Im not clear what each of the Mic types used in the Factory IRs gives tonally, so just tend to scroll through them all until I find something I like. Im sure Id get to a sound quicker if I had an overview of the various mics used and what they bring to the sound. Does this already exist? If not I'll start pulling a list together. So far Ive found 57, 67, A51, 121, 160, 170, 350, 414, 421, 906 which Im sure sound different. Are there any good web resources that cover this info? Cheers.