tube amp will drive von schweikert VR4-jr?

I would suggest 100W minimum. I have a 50 watt ASL amp and it drives them ok, but not in triode mode. I am going to give the bass 200W each channel with solid state and use my ASL tube amp for the mid-high at 30W. The bass driver uses most of the power.

I am using 75W VAC Avatar Super with great results. Not quite as good as SS in the bass department, but overall very good.

I had my Berning ZH-270 (70 wpc) on a pair one day. Not a big room but PLENTY of drive. FWIW.

I happened to be at a party where a fellow was using my amp (McIntosh 2102) rated at 100 wpc and the VR4-jr speakers. Very impressive.

I am currently running mine with a BAT VK-60 but will probably purchase another VK-60 & run in mono providing 120 per side. I love what the VK-60 does with these speakers, it is the best sound I have had in my house yet. I have looked at alot of other amps & think running a pair of 60's in mono will give me the best bang for the buck with the most impact.