McIntosh tube upgrade - worthwhile?


I'm wondering if anyone has ever experienced Sonic improvement when switching from the mediocre JJ stock tubes used by McIntosh?

They tell owners that their tube amps are designed to perform equally well regardless of tubes used.  On the surface this seems incredibly unbelievable.

Anyone notice any changes when they upgrade the tubes? And which tubes do you like to upgrade with. Mostly focused on smaller tubes versus the power tubes which I hear overall don't make much of a difference anyway. But could be wrong.

emergingsoul

swapped out stock tubes for NOS from the 30's and 40's.  no discernible change to my ears, but did experience a discernible decrease in wallet thickness.  Now other tube amp?  striking difference when using quality NOS tubes.....why?  no clue.

I own a MA 12000 integrated. It has 4 tubes in the preamp section. I too wonder if swapping these tubes would make a difference! Where does go besides Uncle Kevin for quality tubes and the right ones???

I swapped stock tubes to Telefunken and the sound improved significantly. Once I swapped, I didn't want to go back to stock tubes. I sold all my McIntosh preamplifier and amplifier and I still have a pretty good inventory of Telefunken over the years.

I swapped out the original mac tubes for Golden Lions and only saw a minimal improvement in sound. It was better but not by much.