With Mrs JPJ off out for the evening, I've had a good play around on the old GarageBand recording my bass. Tracks included: 1) the J-Tone big twin direct into my interface (Behringer UMC202HD); 2) bass recorded with an SM58 again direct into the interface; 3) the J-Tones via my EBS Stanley Clarke DI; 4) the J-Tones via the EBS and the SushiboxFX Finally DI; and er finally 5) and thanks to @Burns-bass, my bass using a Realist Copperhead via the EBS/SushiboxFX combination.
Pre-gig yesterday I'd spent quite a bit of time gain staging my setup (so EBS, Sushibox, Behringer X-Air) and also eq'ing and I had a great sound last night even though I was monitoring via FOH so from behind. Some knowledgable punters commented how full my bass sounded and how it sat in the mix - no doubt down to the time spent gain staging.
As I said at the outset, I wasn't totally unhappy with the sound of the J-Tones but they did lack something and could easily end up sounding like a fretless bass guitar. The Copperhead however is a huge step up. Firstly I needed to back the bass off on the EBS and use the HPF, secondly I was able to open the treble up too and still not get the nasally sound piezo's can exhibit at times. So, all is well that ends well. I'm off to do some more faffing about before Mrs JPJ gets home. Thanks all for your input and help, and for the record, I did like the SM58 recording so a microphone might well be in my future but for now, I think I'm going to be happy with the Copperhead.