Thanks for your replies guys. @Jonesy The example from the start of this video is the kind of thing I was aiming for. He plays a bit before engaging the pedal and it seems to me that the tone is already most of the way there before he does. That's what convinced me that it's more to do with the bass itself. Right now I'm getting something closer to what's on display in this other video (I know he plays with the settings a lot, but the general tonality is the same). I notice that in the first video he's using the 1/4" out (presumably into an amp), whereas in the second he's using the XLR direct out, don't know, is it important to have it running into an amp to achieve certain tones? I have to confess, my strings are quite old but I used the old 'boil them in hot water for 15 minutes' trick and they sound quite new and twangy! Can't remember which ones they are now, they're either D'Addarios or Ernie Ball Slinkies. I'll check out those Rotosound ones you've mentioned though; I was considering a set with a lighter gauge, the low E sounds particularly boomy to me, not really sure though... As for my BDDI settings, I've tried pretty much every permutation I could think of, as well as other people's recommendations.
@Lozz196 Thanks for your tips, I'll give them a try. Might try miking my Laney practice amp with a 57 to see if I can get a better sound. I have the V2 pedal FYI. I've spent a considerable amount of time playing with the dials but it never seems to produce the tone I'm looking for...
Must be a dark art or something!