Dickey himself said in an article that the JBL D120s were the biggest part of his tone. I don't think a JTM45 is far away, any more than a Fender or even a 1987. But it was the JBLs. Not sure how usable those speakers are for most people, who don't play large venues. I've been told they're loud and harsh, so you need to play a bigger place to have the sound develop. But I don't have first hand experience with them. No way as good as JBLs, but I can get a reasonable approximation with my 58RI Les Paul into any of my amps (Kingsley D30, JTM45 and 66 Bandmaster) with a tubescreamer. It honks. Just not as much as the JBLs.