In my opinion, the K9 Pro (ESS version) does not do the DCA Stealth justice. I was very excited about it as a new benchmark in value/performance, but it sounds congested for lack of a better word. No space between the instruments, narrow stage, hard to separate layers. I went back to my RME Babyface Pro FS into the Singxer SA-1 and there's better synergy here for some reason, even with the lesser capable DAC. The RME interface does put out +19dbu, much hotter than most consumer level outputs - maybe that's helping the Singxer SA-1 drive the Stealth better. I have it on low gain and there's plenty of headroom. Volume is set to max on the amp and I'm controlling input level from the RME for volume.
I would take this with a grain of salt though because I've been having a stressful week and that does effect listening impressions in my experience. I would love to hear anyone else who might have tried the K9 Pro (ESS).
For anyone wondering, I recently sold my TT2 to get funds for an LCD 5. I'll probably end up selling one of the three headphones I'll have to purchase a better DAC/Amp in the near future. The Stealth was constantly impressive from the TT2 for me.
@Nomax you really recommend the CMA 15 as best pairing for Stealth? I'm considering it. How does it do with LCD 5 and Abyss, have you tried those by any chance from it?