Blackstar Artist 30 biasing and noise issue

[С-H-A-R-G-E-R]

I have a new Blackstar Artist 30 amp here that have some issues from the very beginning.

It works and sounds pretty decent but I asume it was damaged a bit during shipping as it has some noise and hiss while workng.
The noise and hiss become louder mainly with master volume opened up past halfway and not react on gain and volume on the second channel that much.
Also the noise became signficantely louder when any pedal is used into fx loop. Also there are no any noise in standby mode and it is definitelly not the speakers as I use it as 2x12 cab with my other amps without any noise.
And it sometimes have additional cracking sounds when I play it louder (still at bedroom volumes) or with some drive pedals that dissaper without anything done. So a bad situation.

Anyway I'm going to find a good service but it is not that easy. So any help and advices will be very helpfull. If someone can let me know where the issue can be hidden and what parts and componets to check up first I will be very appreciated.

Also I'd like to swap power tubes as I have a nice pair of Svetlana 6l6GC and one stock RUBY power tube glows brigher then the other. So a good point to start. Can someone please help me with biasing power tubes as this is my first fixed bias amp? I know that are lethal voltages there and understand all the risks. I swaped tubes before just need a help to set it up right. There are two trimpots for bias and balance. But where is test point?
What voltages should I measure and where? If someone help with a complete biasing procedure for this exact amp - this will help to start fixing my amp.

[Haibara23]

I have the same problem with my blackstar lego 2k drive

[Misa9x]

I'm sorry to hear that you're experiencing issues with your Blackstar Artist 30 amp. The fact that the noise and hiss become louder with the master volume opened up past halfway suggests that there may be an issue with the power amp section. It's possible that there is a problem with the tubes, tube sockets, or the power supply. Checking and possibly replacing the tubes could be a good starting point.