I originally powered my NX-Tremes with an Elekit TU-8600S 300B SET tube amp. I loved the sound of that amp but got distortion when I tried to play rock music too loud. A friend with NX-Tremes suggested I try D-Sonic amps. Since they had a 30-day return policy, I ordered the M3a-600M 800W mono blocks. Immediately out of the box, I could hear no difference between the 300B and the D-Sonics. But when I turned up the volume, no distortion and much more dynamics. I could hear the impact of drumsticks on drum heads, the snap of a bass drum, and plucking of strings in a way that I hadn't heard before.
I took the D-Sonics to my brother's house. He has a TU-8600S that I built for him and NX-Oticas. His room is smaller than mine. When we swapped out the amps, we could hear no difference except at volumes that he would hardly ever listen at. His 300B amp is adequate for his room size so he doesn't feel the need to replace it.
I envy all you guys who build these really nice amps. After I retire, I may try that. However, I was afraid that I would spend all that time and money and not like the sound as much as my 300B. I ordered the D-Sonics because the 30-day refund policy removed that risk for me. In the end, I am thrilled that I got that sweet 300B sound with 800W per channel.