Couple weeks back  I ordered a K & K mini and a Pure preamp. Went to pick it up today and found they had inadvertently sent a Pure XLR preamp...whats the difference between the two preamps (ie what will the XLR do that the Pure won't) ?.

The Pure XLR is a more full-featured version of the regular Pure. If you can afford it, I'd cetainly keep it.

The differences are (someone correct me if wrong or miss something):
The XLR version has ...
- Full size knobs for bass/mid/treble eq (Regular Pure EQ knobs are all the small ones except for volume)
- Gain control on the outside instead of inside the box
- XLR out
- Phase reversal - very useful for killing the infrequent low-register feedback (I haven't had any for long time)

Think that's it.
David

Thanks for your comments, I will keep it. They only billed me for the Pure. Didnt open the box till I got home and noticed the error. Nor do I know if K&K or the store made the error but its an hours drive and I aint goin back.