I have had the following CODA gear:
#8 amp, #16 amp, CSiB integrated (from 2019 build), 07x preamp
I also owned the KRELL Duo 175XD that I paired with the 07x preamp for a while.
I also had a Benchmark LA4 preamp ($2500) and I eventually came to the conclusion that the LA4 was preferable to the 3x more expensive 07x preamp. The LA4 is so silent and does not add to the sound, unlike the 07x.
All I got left is the CODA #16 and the LA4. I also have a Holo Serene preamp that sounds great with the #16. I am sure it would sound great with the KRELL Duo 300XD. The Serene is very similar to the LA4 preamp.