What amp/preamp are you using with your Vandersteen Treo CTs?

@referee1  A family member uses this combo set for streaming and CD Playback:

Preamp - Benchmark LA4

Power Amp - Two of this McIntosh MC830 Monoblock

I used Belles Aria pre and monoblocs, as well as Pass XA30.8.  

I just upgraded my preamp to a Backert Labs Rhumba Extreme line stage, a Luxman E-250 phono stage into an SMc Audio power amp.