Musicians Roadhouse

Spent some time swapping around tubes in my 6100LM. I really like the tone and feel with the current setup. Is there any issues with what tubes I have in any of the positions? I'm mainly concerned about the LPS Sovteks. I read all sorts about cathode follower circuits killing some tubes.
v1: Tung-Sol 12ax7
v2: Sovtek 12ax7wb
v3: Sovtek 12ax7wb
v4: Sovtek 12ax7wb
v5: Sovtek 12ax7lps
v6: Sovtek 12ax7lps
v7: Marshall ECC83

Time will tell. They will either hold up or die a quick death, but unlike a power tube dead pre-amp tubes don't usually damage anything else in the circuit. If you like the way it sounds with that configuration play it and see what happens.

One of the LPS I've had for probably 10 years. It was in v2 for a few years. The other is brand new.

Which positions are cathode followers?

The cathode followers are V3, V4, V5, and V6.