I have a Nuforce Ref 9 V3 Se mono amps w/ TDSS level 3 upgrades. They are class D. The standard Nuforce Ref 9 V3 SE amps already sounded very good. It is why I Iooked into the many Nuforce and Nuprime owners that were having their amps upgraded by Bob Smith at TDSS and were very excited by the results. For well under $4000 including the cost of the Nuforce amps originally, I ended up having them done and the result was now like having a pair of super amps for sound. It also made them more reliable than stock. I've used them in friend's houses with very different systems and speakers. In every case, the TDSS Nuforce amps made the best sounds compared to expensive and well reviewed amps they were using prior. The 2 mono amps are so small and light I can carry both under one arm easily. I happen to have a very good TRL DUDE preamp that is 75 lbs. of great sound. I was using VMPS RM40 BCSE ribbon speakers and they sounded great. Now, I have an awesome pair of Vapor Joule Black speakers and the sound is just off the charts fantastic in every way. I also upgraded my cables after hearing the potential of the Vapors. This was the last touch the made a very nice difference. At this point, following a 5-6 year plan I had, there is nothing to want in any way from my system. I will just kick back and enjoy the music. I had Edge and Bryston amps prior. They were both good amps but these with the TDSS upgrades are many rungs higher on the ladder of sound.
Bob
Bob