ima veze koje se dje stavljaju ... ima prednji I zadnji par
Back pair = closer to rear panel. Front pair = closer to front panel.
I kao bolje lampe idu na zadnji par kaze lik iz upscaleaudio - Kevin Deal:
the Pre-2L and Pre-2LSE both pairs of tubes are voltage gain. One may be more pleasing to upgrade than the other for you. There are no rules to that. Try it for yourself.
In the Line 1 and Line 2 we seemed to get the best results by changing just the rear pair. This in an effort to get the most bang for the buck and not do all six tubes. The good news is that both preamps are such that you can mix and match. Just make sure that each pair are the same. So you can put Russian 6922 in one position and 7308, 6922, 6DJ8, CCa, etc in another.
https://forum.audiogon.com/discussions/anthem-pre-2l-tube-rolling-question