Bias setting help needed

I have an Image 34i integrated amplifier (China) powered with EL-34 tubes, and I decided to install the Ei 6CA7 "fat bottle" tubes today.

According to the user manual, the bias setting should be from +0.35 to +0.5V.

The readings of the multimeter's display (digital multimeter Mastech M890C+) are a bit confusing to me - it shows a dot (".") followed by figures. If I interpret the dot (".") as zero, I should set the bias within the .35V - .5V range according to the display, and if it does not mean zero, then I should set the bias within the .035V - .05V range.

The digital multimeter model is Mastech M890C+.

I checked the sound with both settings and with the former setting, the sound is harsh, shrieky and "overdynamic", and with the second setting (.035V) it is musical and relaxed, with pleasant highs and tuneful bass, and at the same time is not slow.

I am wondering which bias setting is correct.

Thanks in advance for recommendations.
Dot would mean point-35 or pint-50 with supressed leading zero format.
You are reading 0.35...0.50V and within the range use your pleasant setting and enjoy the music
Did they supply you with a circuit diagram???
No, they didn't.

Perhaps, one of the reasons is that a bright amp is mated with bright speakers (Silverline Sonata-III), which results in harsh and bright sound. I explore this problem further, perhaps my multimeter's battery is low.