Thanks for the input guys! I appreciate it. I do have one of the earlier versions. They do not still offer the upgrade. Basically, they are telling me if it isn't broke, don't fix it. Tubes OK to replace for sure. I think I will just try their recommendation first and go from there. It all sounds good to me now so I can maybe only improve in small steps.
ARC LS15 tube replacement suggestions
I recently purchased an ARC LS15 line stage to run with my ARC VT100 mkIII amp. Everything sounds great but I have no idea how old the tubes in the line stage have been in there, so I would like to change them out. Audio Research suggests the EH tubes they stock at the factory. I have friends telling to go NOS and I have reached out to a couple of dealers, and they wouldn't really make a suggestion. I know there are some folks on here that either have or have owned the LS15 that can give me some feedback. Thank you!