As a current owner of the 2stepdance amp, I've noticed from day that the amp emits a hiss that gradually increases whenever the volume level is turned up. While the hiss only starts to become noticeable when past 12 o'clock on the volume control (zero hiss under this volume) using moderately sensitive iem, it becomes extremely loud at max volume and is a concern when I've read from current 2stepdance owners that they doen't hear any noise, is dead silent at any given volume. In additional, I'm getting frequent radio frequency interference when using it as a portable amp, whether I'm outdoors and commuting on public transport. It seems the RF signal is only present through the right side of my headphones. It can be heard though my music at a moderate level. Do you think I have received a faulty model?