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
The Stereo 50 I had sounded great,  VTL's response to second hand owners of their legacy products..... not so great.
There should be holes, two for each tube.   One is and insulated test point.  If you look inside the other hole , you will see a potentiometer pot... i think it was blue with a white adj. slot.
What is the actual model number/name of your amp? If we have that we can do a quick google search for images of it.