I had my DAC on mute when I wasn’t listening. I don’t have a separate preamp, my TT2 feeds my amp directly. All that‘s needed to burn in a server is to have it sending music to a DAC continuously.I've also got a K40 coming as a replacement for my CX which will feed my Devialet 1000Pro. Haven't read ANY reviews on the K40 (only K30 and K50) so wondering what it will sound like compared to the CX.
When you say playing music continuously did you just have the K30 playing music, but didn't actually have your amp on to play music through your speakers, or do you need all on for the burn in process to fully work?
Note also that if you use Roon, it might be busy analyzing music after you first configure it. That can degrade sound quality.
I would strongly suggest reading the AMSv3 manual in advance. Antipodes does something different with storage that’s actually very smart. They create a single Logical Volume that’s shared amongst all server application. This is described starting on page 10. I added a 4TB Samsung 860 EVO to my K30. This is only partially full with the rest of my music stored on my NAS. Their approach brings it all together nicely to appear at /storage/music. Their software implementation was very much a pleasant surprise. I switch between Roon/HQPlayer and just HQPlayer (with Roon stopped).