Ive owned the vr-4's with a Number of tubed amps, Rogue has the drive do do the lowend justice, The rogues on the other had do Not have the mid range lushness.
A set of Golden Dragon kt88's Might just do it.
Another nice that grabbed the vr-4 by the balls was VTL Deluxe 300's.
Worst sounding amps Krell Mda300 mono blocks,