For the OP, RCA connections (also called unbalanced audio) are susceptible to interference. Be careful NOT to route them close to any high energy source (amps, speakers, power supplies, etc.) as they can pick up noise or be distorted causing your output issues. One guy (donât remember if it was here or on the Serato forums) was having a similar issue but his was sporadic, he found out it was his iPhone every time it would push email or receive a text! So donât leave your phone near your RCA outs
The ground loop isolator JayRuss was talking about attempts to remove any voltage offset in your audio signal (basically an induced voltage from a particular set-up). Just Google âground loop isolatorâ to see how it works. Before going down this route, try to see what is causing a distortion to your signal. The isolator may be the solution, but look âeasyâ first.