I ran the Gungnir/Mj combo with the HD800 (non analmort mod), LCD-2 rev.2 and HD650. The issues I had with the Gungnir were evident through the more forgiving headphones. For me, it went beyond being just a bad match for the HD800.
The Gungnir did impress initially, with its unbridled energy and the apparent improvements on display over the Bifrost. Over time though I found my system too obnoxious. There was too much zest. It was a constant punk-ish assault, shouty and abrasive. There was a lack of finesse, a deft touch when the music called for it. These qualms disappeared with the M51, confirming the Gungnir as the culprit.
My Gungnir was an early unit with the gen.1 usb board. Fwiw, I also employed optical and found the same faults. I'm intrigued about the improvements from the gen.2 board, but on reflection and knowing purrin's preferences - I suspect history would repeat if I were to give the Gungnir another chance.
edit: This post may come across as "bashing" the Gungnir. That's not my intent. It's a component that undeniably presents bang for buck and there will be systems that strike a great balance. There are also people who love to be pummelled in the ears (purrin being the poster boy). For me, the Gungnir/Mj was an OD on energetic presentation. I find there's a misconception about the Mj but a lot of that stems from the Gungnir's attributes imo.
Edited by olor1n - 12/7/13 at 5:07pm