Tube match problems


Hi Everybody

I’m new here and would like to ask for your help. 

I got VTL power amp with 6l6 tubes. They were perfectly match. Unfortunatelly when I was recently moving, took out tubes and forgot to mark tubes against sockets. Now I’ve connected back whole my set up, most luckily tubes in wrong sockets, it doesn’t play as it was. I don’t have tools to check bias and it really difficult to find any place dealing with tube amps in my city. Any ideas to solve this issue, which makes me crazy :(((
mn
I had a VTL Stereo 50 and it has external bias points.  The voltmeter's positive probe goes in the test point and the negative probe goes in the negative speaker binding post of the channel you are biasing.

https://vtl.com/support/tube-biasing/
Thanks for reply, oddiofyl. 
I have already red this article in VTL’s site - good one. 

Could you check the link that I posted above, photo of the amp similar to mine and could you advise the test point. To be honestly, I’m struggling to recognize it. 
The Stereo 50 I had sounded great,  VTL's response to second hand owners of their legacy products..... not so great.