I've got the Acoustic brand AC60, that's a Guitar Center house brand. What I liked about it is that it has two channels, and each channel will accept two inputs. Each of the four inputs can be XLR or 1/4. It's a funky looking jack, but it works very well.
With this set-up, you can have a second player/singer with you and you can either each have a channel, or you can both be run through the first channel and put both your instruments through the other channel. Each channel can be mixed - so if you are playing by yourself and you decide to put both your guitar and your voice through the same channel so that they each have the same amount of whatever built in effect you are using, you can still "mix" the voice and guitar to a level you like.
I've been very pleased with this amp. I just use it at home for jamming and for practice to hear myself through a mic, but I think it would be suitable for small gigs. It's worth checking out at the store if you have a Guitar Center nearby.
Other than that, there are some real good ones available with fewer inputs. I just wanted the additional inputs so that I wouldn't have to use a mixer if a friend came over.
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