Hi. I've been searching for a while, but can't find an answer, so I'll throw this out there. I've been using my HD500 with DT50 and L2T through L6 link for a couple of years. No problems at all... until recently. No longer any sound through amp or speaker. If I run the HD500 to the DT50 through the standard line out, it works, but there's a pulse every 5 seconds or so and the sound cuts out for a 1/10th of a second. Firmware/flash up to date. Any ideas or suggestions?