Of course people can learn! My point is that a tuner is not a good candidate for conversion to a guitar preamp. I you really want to DIY, then dig up some schematics, spend some quality time with some reference material on tube specs and circuit design, and either build from scratch or pick something more suitable to modify.

rockonn91 obviously has some clear ideas of what he wants to achieve, and I told him not to waste his time on a tuner.

Radio Shack (now called "The Source"?) proto boards represent a step or two up from what I got my start on. I would recommend the audio output of an old tube table-top radio as a much better place to start. If you have the interest, go with it. Just do some research first, and be very careful playing with those lethal voltages!