Which replacement and upgrade tubes are particularly interesting for PrimaLuna?

With PrimaLuna, tube selection is particularly interesting because the units usually work with EL34 or KT88 from the factory, but the manufacturer also explicitly approves alternatives such as 6550, KT66, 6L6GC, 7581, KT90 or EL37. In the small-signal stages, 12AX7 and 12AU7 also play an important role; PrimaLuna itself points out that noise often comes especially from these tubes. For models of the EVO series, therefore, not only the correct power tube is important, but also a clean selection of the preamp tubes. Many suitable tubes for PrimaLuna are also available from BTB selected, as matched pairs or as premium-matched quartets.