I just got my Sonic Port today and have come here because of the very same problem. Connecting the line out to my bass amp, the sound level is very low, even if I take everything out of the signal chain. The output to the headphone jack is non-existent. I'm using Positive Grid's JamUp program. Sounds fine if I plug headphones directly into my iPad or iPhone (tried both), but little or no analog output from the Sonic Port itself. I suspect a defective unit, but any advice or insight is appreciated.