Definitely agree with everyone that suggested the Joyo American Sound pedal. I own all of the Joyo preamps in the range and use them very regulalrly. You can use them directly into a PA system or straight into your DAW. I like 'em for those two reasons in particular. But I know a few guitarists that use it as a regular stompbox or as a "second channel" for your amp. For the price you pay, it's incredibly hard to justify even buying the Tech 21 version. With the American sound you can get anything from Tweed sounds to Blackface.

I actually compiled a full Joyo clone list if you want to read about these pedals further: http://guitarpickzone.com/joyo-clone-list/