Why not consider the Holo Serene preamp which obviously should be good with the May. The Serene only adds a touch of warmth. It is a tiny amount, and you get a super silent unit. I have the Serene and love it. The Benchmark LA4 preamp is similar in all aspects as the Serene except it does not have that tiny bit of warmth. I also have the LA4.
Both of these can be used with ANY gear if you like the sound of your other gear and do not want the preamp to add to it, especially the LA4.
Recently, I started listening to my slightly bright RAAL CA-1a headphones with the Serene and Benchmark AHB2 amp. This combo with the LA4 is a bit sterile. With the Serene is it not really warm but not fatiguing and a very clean sound. That combo was so good I cancelled my plans of selling the AHB2 amp.
I use the Serene with both the AHB2 and a CODA #16 amp with a Schitt Yggi+ LIM DAC. I used to have a Musetec 005, which is favorably compared to the Holo May KTE DAC (see the thread on A'gon). I never had the Serene and Musetec together, but I know that they would work great. Just like the Holo May KTE and Holo Serene KTE.