I recently took the ts-808 circuit schematic, and made a number of changes that should hopefully make it work great with bass.
I replaced the input buffer with a jfet design that's part of a clean blend circuit. The volume control of the tube screamer circuit is now a trimpot, so that it can be adjusted for unity gain with the clean signal when the blend is halfway. After that, I replaced the output buffer with a lpb-1 circuit to provide plenty of volume for an output boost. There are also several changes that do things such as increase the bass going into the clipping amplifier (as well as a bass cut later on in the circuit if you want to dial back a bit), and increase the transparency of the tone control, as suggested by the amz website.
I'm also starting to design vero layouts for my own designs. I plan to verify this myself as soon as I have a chance to order in parts for it, but if anyone is willing to give it a try, please let me know how it works out.
Also note that since this is just a design til it actually gets built, some of the components may be better suited with different values. If anyone finds this to be the case, please comment and let me know. Cheers!