NOTE: USB power has inherent ground noise, so when connecting the UNO Synth directly to your computer via USB, you may hear more noise and interference than when the synth is connected to a USB wall charger or running via batteries. With the direct computer connection, you can reduce the USB ground noise and other interference by either using a USB isolator or a custom TRS cable into a balanced input on your preamp or audio interface where the ground is not connected at the balanced input side.