At low to medium volumes, any of the amps will do fine as for power. The only caveat to tube amplification is you want to check and make sure the Vandersteen's low end sounds suitable using the amp you select. Sometimes, the low end can sound bloated with the wrong amp. The ARC amps are wonderful with this speaker.
Also, make sure you get these speakers set up correctly. It takes some time experimenting but it is well worth the effort. Follow the instruction manual and all will be fine.
If, depending on room size, you want to go over about 85db, you might want to look at more power. A good test is track one of the original Jurassic Park CD. It will let you know pretty quick about your bottom end requirements.
Also, make sure you get these speakers set up correctly. It takes some time experimenting but it is well worth the effort. Follow the instruction manual and all will be fine.
If, depending on room size, you want to go over about 85db, you might want to look at more power. A good test is track one of the original Jurassic Park CD. It will let you know pretty quick about your bottom end requirements.