Better tubes make a mediocre amp better but would go so far as transcending it. On the other hand, the are great amps made with so so tubes and still sound great. I would say great amp transcends modest tubes
Can excellent tubes transcend modest amps?
I am wondering how far a good but not amazing amp design with decent parts such as Antique Sound Lab AQ1003 DT or a Jolida 302B can be improved by putting top notch NOS tubes? In other words, is it worth buying a used $500 integrated and give it an extreme tube make over for $200-400 rather than buying say a PrimaLuna or Cayin in the $800-900 range with its stock tubes?