you've got me thinking about this And also, I recalled that with headphones everything was fine. Small edit: I listened to the headphones when amp was on the table, and the DAC was sitting next to it, not on the top. Spent more time listening on medium gain today. It's clean as it should be! And driving Kefs quite good! Shit, I'm really sorry for posting misleading thoughts. The amp is cool! Am I an idiot? I regret to admit that it's true to some extent. I didn't notice it as I switched to higher gain, listened for a minute, and switched back promptly as I believed that it was bad. However, when I posted my first post about the rag, I clearly heard some harshness on the top of the spectrum. And some of my friends preferred the lowest gain. It's considering I didn't tell them what I changed and what to expect. Tried switching back and forth multiple times back then. I honestly don't know what was causing the issue, but I think part of the problem was that the equipment was sitting on the floor stacked on top of one another with nothing in between. Also, I changed crappy SMPS to sbooster on the source as well since then. And some other things. I guess, the distortion was just more audible on higher gains at that time.