I Was browsing on internet and I read that the minifooger DRive and the moogerfooger 107 do a good job if you want to make your tb-303 scream… Especially the 107 can really help you to do a lot of stuff…
I’m also using an MXR Distortion+. Lovely distortion but I find it tricky to use live as it turns the input down a few dB’s when you turn it on. Definitely sounds sweet on my Freebass 303 clone though.
I have a Rat to use with my x0xb0x and TT-303. Made a quick video when I bought it a year or so ago…
I’ve found that the Rat sounds great with my x0xb0x but not as good with the TT-303. Not sure why that is exactly, must be something to do with the different harmonics of the two machines.
Also I don’t know if you have an A4 but have you tried running the 303 through the filter overdrive. That sounds pretty good!
Previously I’ve used a Boss md2, MXR distortion+, rat and tube screamer with my x0xb0x. However I recently picked up a line 6 m5 for a song and it sounds bloody amazing with the x0xb0x. I’ve tried Line 6 effects before and hated them and admittedly the m5 sounded like ass on everything else. Maybe the hot signal from my x0xb0x works well with the m5? No idea but now I’m considering a second.