I thought the A2 upgrade was able to drive as low as 600 ohms, but just double checked with Schiit's website. They said 600 ohms about Yggdrasil, but didn't mention it with Gungnir. It should handle 10k ohms just fine, as Ragnarok has 10k ohms. Your 3 amps adds up to 7k ohms, which isn't much lower, but seem low enough to upset Gungnir. I had thoughts about driving some special sauce loads with my Gungnir, guess it might not work so well after seeing this post. Another way to get around is to snug in a preamp right after the DAC. Most of them should handle low impedance just fine, and might even be strong enough to drive headphones. It's a great excuse for getting more gears. BTW, I might have missed it, does your Gungnir still distort now when driving only one amp?