Yeah, the 530 doesn't have the famous studio clean tones ENGL is known for in their other amps. I reviewed the 530 and noted that the cleans were more Marshall-like in character than, say, Mesa/Boogie. So if you were to get a JMP-1, you wouldn't have any better clean tones than you do now. In fact, the JMP-1 has classic "Marshall calls this a clean tone" sound that doesn't compare to the clean tones from a modern Boogie or other ENGL amp.
However, +1 to the poster who almost got this point right -- a JMP-1 modded by Voodoo Amplification will sound great. But note that this is NOT Voodoo Labs like the poster said. Two different companies.
I'd recommend the Mesa/Boogie Triaxis if you're sticking to a single space unit.
Here's my in-depth review of the Triaxis:
http://www.musicplayers.com/reviews/gui ... xis290.php
But also, your Boogie 20/20 is a limiting factor in getting great clean tones. It's got EL-84 tubes and a lower power rating, thus it doesn't have the same kind of headroom you'd get by stepping up to the Boogie 2:Fifty or the Simul 2:Ninety.
Scott