Preamplifier K8020 issue

Hi, I bought and mounted the high-end kit Valve Control Amplifier K8020. After mounted it, I found a malfunction. The volume of the left channel is about 3 dB higher than the right channel. I swapped the valves, swapped the capacitors C21 and C22, swapped the C18 and C19 capacitors and redid all the welds but without solving the problem. While checking the correct position of the different components, I found in the assembly manual (on page 26) that the value of the resistor R8 is 330R (left-in / out section). In the list of the resistances on page 9, I don’t find the resistor R8, but there is the R08 of 10K value. Maybe 330R value for R8 is incorrect on page 26? Because in the kit there isn’t the resistance value of 330R.
What can be the problem? What could be the solution?
Thank you for help.