If you bought the tubes new then youre good to go. Realistically from its condition, they are not far from the benchmark reading of each other being from new. With primalunas technology, your tubes are suppose to last much longer than most of competing amps. that’s been primalunas proven history since 2001. Besides the adaptive auto bias, the tubes are dialed slightly lower on heater voltage enough to run it with the same performance as the same as the regular .55mv per tube on the KT88 family.