Ok, this is good. I'm seeing good stuff on these and the dsl40, and I'm leaning heavily toward the dsl40cr (it has master volume control). I also see some jcm200 dsl50. This is a lot of letters and numbers. How's the dsl20 or 40 compare to the jcm2000 dsl50 or jcm2000 dsl401, beside the obvious wattage difference?