With those speakers I would not go with tube gear. They already have a beutiful smooth sound. Special 25's are very different. For contours I would go with solid state. You will definately get significantly better sound with a better amp. The NAD is a good budget amp, but you are missing out on what those speaker can do, for sure. I would consider a Plinius 9100 or 9200 if you can swing it. Also consider Bryston B100. Another good choice would be NAD M2 or M3. If you have a tight budget look at the NAD C375bee. No better amp for that money and it will make your Dyns sing.
Looking for Integrated Amp for Dynaudio 1.3 MkII's
Have read some comments that these speakers need power to deliver their best. Currently I have them hooked up to a NAD C320BEE Integrated Amplifier. Not sure if the NAD has the power to get the most out of the speakers. Any suggestions on an integrated amp that would go well with the 1.3 Mkii's? Is the NAD C320BEE underpowered? Thanks in advance.