The key to the TB-303 sound is really the glide function as well as other aspects of the sequencer, and how these make most any typical single-VCO patch behave. The problem with the actual stock 303, IMHO, is that you have a very limited range of possible useable sounds, hence the various modded versions (such as the Devilfish) that popped up in the 1990s to alleviate some of this.
Frankly, I find that when I want a 303 "acid" sound, I turn to software. There are several software sequencers that more than adequately model the 303's sequencer behavior, and once that hurdle's been passed...well, I've found that a software knockoff of the Juno-60 works FAR better at sounding like a 303 than the oodles of "worshipful" 303 synth clones out there. Trying to make a modular synth emulate the TB-303 seems to me to be akin to buying a Lamborghini Countach simply to run errands around town.