Novice tube rolling question - Line Magnetic LM-218ia
Question from an almost-novice for all you tube rolling experts out there!
I recently acquired a Line Magnetic LM-218ia and am happily rolling the tubes. The manual states that the stock driver tubes can also be replaced by EL34, KT88, 6550, or 6V6. (When I got the amp, it actually had 6L6GC tubes installed as drivers - and it sounds great!) I had assumed thus far that these different tube types are all drop-in replacements that can be safely used in this amp - drop ’em in, bias them up using the ampere meter built into the amp, and go - but now I'm wondering if that's actually correct.
I have talked to some other owners of this amp who have expressed reservations using some of these tubes interchangeably due to the higher heater current and lower max dissipation in some of them. I do want to make sure I am treating both the amp and the tubes right, and of course always want to be operating the amp safely. Is there any issue dropping these different tube types in as drivers? Does bias need to be calculated and/or set differently for any of them?
For example, I was about to roll in a pair of the Svetlana winged "C" 6L6GC... any issues there?
Thanks for any and all advice!