Hmm, I'm going to try to be serious here. We're talking about a 2 channel head, a 3 channel head, or the 3 channel reborn?
1) What guitars are you using?
2) What pickups / electronics are you running in your guitars?
3) Once you have steps one and two figured out, you may want to consider some actions on this.
Things I have found improve clean tone on a Dual. (Unfortunately, they take away from the dirt tone in most instances)
-Running 6L6 tubes instead of EL-34s. The bell-like Mesa STR454 tubes are great for this!
-Running Yellow Jackets with EL-84s. (at the expense of a heavy and modern dirt tone) If you are into more vintage tones, running Yellow Jackets with a Marshall 1960ax cab is absolutely mind blowingly awesome. Just be forewarned, this will turn your Dual Rectifier into a totally different amp.
-Running greenbacks or a cabinet otherwise geared to cleans. Again, this interferes with crushing modern gain tones.
4) If no tweaking or part swapping is remotely appealing, you might have to get your head modded. Voodoo amps has a mod that breathes life into the clean tone. The other option is to buy a Fender Blackface and an AB box. Then you can lug two amps everywhere you go!
I think in many cases, having a great clean sound and a great gain tone is hard because the conditions necessary to create both of these scenarios are in direct opposition with one another. I think this is why the Road king allows for two cabs to be hooked up, one for clean and one for gain. Of course, the Electra Dyne / Mark V are notable exception to this phenomenon.