Low watt system for rock,electronica?

Art Audio Jota monos with 52BX or 52B tubes. ( just don't drive B&W and Wilson at high SPL ) :-D

Seriouly, if you use horns or single driver speakers, low watts, even a single digit amps go a long way. As long as you are realistic and choose a speakers sensibly, these single-ended beauty can pull off electronica convincingly. I listen to a lots of dance/electronica on my 30 watts tube amps.

OR, try a newer Naim amplifier. They are lower watts but more dynamic solid state out of bunch without sounding strident. ( meaning it's excellent for chill/ambient stuff, too )

I bet the system described above sounded pretty good!
Rethm is extremaly fast and dynamic.

I think in order to play convincing electronica/ pop/ rock, you need both a good dynamic and flow and preferably with enough headroom to be able to go loud without a strain.

Personally, I prefer SET or even pushpull amps playing electronica than most solid state based systems.