Interesting. I had an HRT Microstreamer that had issues on one computer where it just wouldn't work. On the other computer it worked perfectly fine, but on the other, it'd cut out after a few seconds. HRT was pretty good about working with me to troubleshoot, but at the end of the day, I decided to just sell it and get something that works.
Have you tried it on different comps? I assume you're using Windows; you might try finding a friend with a Mac to let you test it. Supposedly the problems I had are not a thing on iOS (I made sure the guy I sold mine to was a Mac user and he reported no problems with it). This might show if the unit is actually defective or just not working with your setup.
Anyways, this thread had turned into a real gear-porn thread! lol Currently I'm using the LC with my Theta Basic II DAC in balanced mode and the HE-560 headphones with a balanced cable that I made myself.
I plan on doing some testing on the LC with the same DAC in SE vs Balanced mode to hear the difference. I'll do the same test with my Audio-GD NFB-28 and see if the LC handles the SE->Balanced conversion any better than the other balanced amp I have here. Why, you ask? Why not, I ask you in return!