Bias Jolida SJ 302a EL34 tubes.

I have a question about biasing the tubes for my Jolida amplifier. (I believe I have a bad tube because when I move it to the opposite channel the distortion moves with it.)

In the manufacturer is documentation it states the proper value to be 400 millivolts, but from other sources it’s stated as 40mV. What is the discrepancy there?

PS, if anyone has a copy of the owner’s manual for this particular amplifier I would love to have one.

Thanks