Re: preamp for AKG C411
Joe Meek ThreeQ would be an elegant solution (I picked one up for around your pricerange).
Nice sounding preamp and EQ. It has an insert point so you can put a muting tuner in line... Very handy.
The output is balanced TRS, use a TRS to XLR adaptor and mic cable to get into the mixing console.
Hereby & forthwith, any instrument with an odd number of strings shall be considered broken. With regard to mix levels, usually the best approach is treating the mandolin the same as a cowbell.