A good first preamp build?

[dragonbat13]

OK I have been researching for a week now on how to build my amp. I am almost sure I want to go with a 102 type build. I also want to employ the Jazz/Rock feature into it, although I dont exactly know what this means. I am only going by recommendation on this. Its gonna be 50 watt 2x6L6 to keep things simple for now. Using a Marshall 50W JCM 800 OT.

So anyway a 102 preamp layout is what I am almost sure I want, going off of others descriptions. What I want to know is what is really necessary to get as much out of this D'lite and what isnt. Is the relay setup only for footswitching? I dont use footswitches. Do I need an HRM tonestack in the OD section? I do plan on installing all three switch setups in the front. I am not looking for a blues amp. I have enough of that already in my lineup.

There are two things I am still totally lost about,

what is this FET stuff?
And will I need to install a choke?

From what I understand the dumble amps are supposed to have good touch sensitivity, harmonic texture, good note definition when overdriven and good sustain. I am shooting for that more than anything. Thats why I took the advice and went up to the higher power.

And I have been searching, but I feel that its rather hard to get a good idea on the differences between the different setups through a pair of computer speakers.

I guess what I am saying is I would like to build the amp with the least amount of extras that are not needed (like footswitching or effects loops). I would add them later if I wanted.

I have, however, been learning ALOT about coupling circuits, bias, transformers, and tube specifications among other things. I had to refresh my memory from a few years ago.

Thanks for any help.