I have used the Placette RVC, Active, K&K SB102, and the Bent TAP with autoformer. The Placette Active was noticeably (it too very little time to notice) better than the RVC in my system, much better bass drive and control and I don't think it had much to do with impedance matching or sensitivity - my system is very passive friendly. The K&K for some reason simply did not have the dynamic drive of the Placette Active. The Bent Tap with autoformer (I suspect the K&K would be very similar to the Bent Tap with the SB 102 transformer)was the best of the lot in my system with the Placette Active a close second. Ultimatley, while I loved what all of these passives did not do (they all sounded very good, and certainly good values compared with comparable actives), at the end of the experimentation I always came back to an active tube linestage - they simply sound more like live music to me, and of the many I've tried the Dodd Battery preamp is the one that works best in my system (I also tried CAT, Joule, Lamm and ARC) - like passives, it is also off the grid making for exceptionally quiet S/N performance with a livelier performance that always seemed out of reach with passives. I do think that passives are a great alternative to much more expensive actives, but I think the end of the road will take you to a quality tube preamp.