Build your own tube preamp pedal built around a 12AX7 tube. Go from clean, warm tone to smooth, real tube overdrive. This kit includes pre-drilled die-cast aluminum enclosure and all parts with easy to follow instructions. All you need to provide is solder and soldering iron. Operates on a 9V battery or AC adapter, which is not included. When completed, this pedal draws considerable current and battery life will be short. The godlyke 9-volt adapter (our part number M-PAS-S) may be purchased separately to power your new pedal.

http://www.amplifiedparts.com/products/accessories/K-930