Yeah the JJ one is fairly weak, if he weren`t playing a Stranglers bassline possible not many would think it was meant to be JJ. For me as well as the blown speaker it`s valves, I`ve always found it much easier to get near the JJ sound through a valve amp, there seems to be a chunky but smooth aspect in mids in valve amps. Many years ago I had a Dave Hall DH1 and it did that nicely. Of course a lot of it will be down to how he was playing at the time, angry young man playing angry new music.