Just built one on january

look at the general guitar gadgets http://www.generalguitargadgets.com/effects-projects/amps/tda2030-amp/

You can use a TDA2050 for more volume as i did.

the thing about it is that it need a dual powersupply but that should not be too hard to make.

just my opinion

Why not build the power amp and use the tubescreamer as preamp first. hehehe 

Also ive guild my amp using a 12au7 for preamp into and equinox reverb then into a General guitar Gadgets TDA20x0 power amp.

I have pictures here https://www.ssguitar.com/index.php?topic=4180.0

i also added an effects loop and a Turn on continuity delay circuit (for speaker) to eliminate the turn on pop

Just Sharing

this is a 12au7 preamped GGG tda2050 amplifier.   i included a reverb circuit in there



I built in in sections/modules



Gut Shots



Its louder than the other amps ive built.  Initally it had a turn on thump/pop.  I did not that pop.  mostly it was considered normal everywhere i tried to research but i found a way to completely eliminate the pop/thump.  I use a DPDT relay controlled by a 555 it delays the continuity to speaker approx 3-4 secs. and during that time diverts continuity to a dummy resistor load.    Now its completely flawless on startup.