Was it Kevin, that mentioned having all four of your LS-16’s tubes matched? If so- did he elaborate? Just curious(he does know his stuff).
No, he never said anything about the LS16. That's just my opinion, just like your opinion on mixing and matching. I think, that on this preamp, it's not a good idea, but again, it's just my opinion. I was only an ARC dealer for many years and have owned almost all the preamps that they have made, but, again, this is my experience only.
Some of the older tube preamps benefited greatly from mixing and matching, so it really depends on the circuit.
@n80...Nothing wrong with trying, just don't drive yourself crazy. Yes, it can and will happen :-)