Zach at TITAN amps did his SLO100 lead channel mod on my JCA100 a while back. That combined with 4 JJ's KT66 power tubes really helped wake this (already great) amp up a bit more on the lead channel.
I'll continuously post updates and clips of profiles I make of this amp. Lots of cool tones in it. This is just a quick profile of the lead channel with the gain at about 10 o'clock.
http://www.tonefinder.com/files/62-Kemper_JCA100_1.mp3
Profile is uploaded to the rig exchange. Cleans up really really well using the gain knob on the amp. Surprising considering the real amp can't even do that!