which tubes for which genre ?

Matter of fact: A pair of VTL 300 Monoblocks would be a perfect match for your speakers(if you have the room). Whatever load they are wired for will receive their full rated output. Just be certain they are internally connected for a 4 ohm speaker(easy). WON'T break the bank/WILL rock the house! Very fast slew rate for a tube amp(more detail/accuracy, better imaging, great soundstage) and excellent bottom end.

thanks for the advice guys, let me start from the beginning do the audience 42's match better with ss or tubes ?

For rock, I would recommend KT88's in push pull.

This will give an easy 30+ watts clean.

KT88's give a very linear uncolored sound.

John C.

I agree that a higher powered push pull amp like vtl,manley
audio research,quicksilver and cary would be my choice for this speaker;but if you can $$ a atmasphere ma1 or ma2 I would look at those as well.
If you able to audition amps in your area I would listen to all that you can; how big your room is will be a important factor as well.

What amp do you currently use to drive the Dynaudios? I share the skepticism of some who have posted responses to you -- if you want to rock, I don't see why you're thinking of tubes. I've owned a variety of tube amps and preamps -- Conrad-Johnson, Quicksilver, Primaluna, Audio Research, Eastern Electric, etc. They all had their attractions, but since picking up a Naim Nait 5i integrated a few years ago, I've had no desire to go back to tubes (which can demand a lot of care and feeding, esp the power amps). But I have a small room and mainly listen to jazz and classical, not rock, so your experience may vary. I still think it's worth thinking twice about WHY you want to go tube -- what goal are you trying to achieve? There may be a better means to the end you seek.