I don't think I've ever heard dark psytrance. Suppose I'll have to add it to the list of things I need to try.
Anyway, you want lots of tight, deep bass, right?
The HD-650 works great for that. Though they're particular about amps. For deep, tight bass you'd want clean solid state with lots of power. The classic example is the Dynalo/Gilmore Lite. A bit over 1W of power and clean and clear as the morning light. You might also want to consider the M^3 which can be built with a variable bass boost control and the new O2. I haven't head the O2, but it sure has clean measurements. So, no, you do not have to spend a fortune on an amp. But you will have to spend a few hundred on the right one.
As for the Denons, they produce a lot of bass that I don't find particularly clean. Clean bass in closed headphones is hard to find. Most people are happy with the huge amount. The Grado RS-1 is quite colored. I enjoyed a pair for several years then burned out on the sound. It was like having ketchup on everything I ate. The HD-650 has a slightly dark coloration overall, but it is evenhanded and not too bad. The HD-600 is a bit more neutral.