Best amp for VonSchweikert VR5?

I had my system optimized for the VR4's before I had Albert upgrade them with new VR5 components (including new drivers, crossovers, wire). Now with the new parts including soft dome tweeters I seem to have lost some immediacy,definition and detail. I think my Plinius SA 100 is part of the problem, it seems to be a little soft in comparison to my old Sumo "The Nine". My system includes VSA VR5, Plinius SA-100, Melos MA-333, Sony SCD 777ES, Audiotruth Argent biwired, Purist Elementa, JPS Superconductor+. I listen to anything from Mozart to Metallica, with a HUGE interest in the BLUES. Albert has had good luck with the digital Bel Canto amps. Spectron,Rowland,Krell,GamuT,McCormack, may also be a consideration. Thanks for any input.
Aloha from Hawaii:

I have the original VR4, and they are singing. I am running Unison Research Mystery Two preamp (Italian tube amp manufacturer, and their Smart 845 mono blocks. Amps are gorgeous, huge, and fantastic sounding. 25 watts per channel, single-ended. I consulted with Albert and with Prof. Sacchetti, the designer/founder of Unison Research, to make sure the amps would drive the speakers. They do, beautifully.

Sources: Nottingham Analogue Interspace turntable w/Benz Glider cartridge; also N.E.W. Ventura tube output CD player. CD player sounds better than any other I have heard, but nowhere close to analog turntable. Vinyl rules.

As for your lack of immediacy,definition and detail, I wonder: how long have you had the upgraded speakers operating? Perhaps they need to break in?

Let me know if you have any other questions about my system. You can email me at

i dont think its the amp at all you've goot a good one. poster above has good idea let your speakers break in more...
I do not think break-in is the problem, I have had the VR4 to VR5 mod since early this spring and have played them many hours at loud volumes.
Since I am familiar with you equipment and talking to you,Break in is not the probelm.Though Plinius is a very good amp it also has matching problems (as do many other components) in your system with the VR5s.Both cabling or the amp could be the culprit.Albert has had very good success with Bel Canto,and so have others,He will be using Spectron (as well as Bel Canto)in this upcomming CES.I have 3 clients that have had extreme success using both of these amps and VSA speakers.
interestingly enough, i have the same electronics as terry.
Unison Mystery One and the fabulous Smart 845"s.nothing produces mids and high like an 845. i would not go so far as to say that the bottom is up to that of a really fine solid state amp. but overall i would certainly not trade the virtues of the single ended triodes for a little more bottom end at any cost. the combination of Unison and VR is wonderful. i also use a tubed CD player, BAT.
I recently replaced the Discovery +4 XLR interconnct between the Plinius amp and Melos preamp with JPS Superconductor+ RCA's. I have regained some much needed sparkle and dynamics. With the balanced Discovery I could not turn the volume past 8:00 because it was too loud. Now the JPS IC with RCA's doesn't get too loud until about 9:00. The balanced circuitry must have more gain. I also run the JPS superconductor+ IC between the Melos and Sony SCD777ES with good results.If I change amps now it may be for the Plinius SA250 for more balls.Can anyone recommend any aftermarket power cords for my electronics?Plinius SA 100Melos MA333Sony SCD777ESEAD DSP 7000 DACThank you for your time.
Try cords from TG Audio, from your post, seems like the new TGA SLVR pc might be just the ticket. Wire guru Bob Crump makes some great cords, plus they're reasonable. You might post a query for him by name over at the Cable Forum of AudioAsylum. Bob usually responds personally to questions re:TGA pcs and is happy to help tune to your particular system.

BTW, I heard the Spectron Musician II with VR4s last spring and the sound was excellent.