I took a couple of plots of the K3’s Line output compared to the Headphone output
For these plots the K3 was connected to a wideband noise generator. measurements were made with my Delta 44 soundcard
The line out is in green. the Blue trace is the headphone output with the volume set to match the level of the line out
The first plot is with the line output level set to 100, the second plot is with the line output level set to 5
