There are two possible causes.
- Have you connected an analog player with a built-in phono equalizer? Use a LINE route for the analog player with a built-in phono equalizer. If the analog player with a built-in phono equalizer has a PHONO/LINE selector switch, switch to PHONO and use a PHONO route.
- Is a USB sound card (audio interface) for computers connected between the analog player and this unit? If the output of the audio interface for computers is line level, use a LINE route.