I purchased a E7 with the intention of using it as a headphone amp/dac with my iPod and to use as a dac with my laptop running Audioengine A5+ powered speakers using the optional FIIO L7 line out doc to connect my laptop to the E7. The whole system worked great for about 3 months, but then for some reason the E7 stopped working with my laptop,,,,,still would work with the iPod, but utilizing the DAC with my powered speakers completely stopped working. I went through the process of going to FIIOs online support but they would not help me in a normal...