I use NOS Sylvania "Chrome Domes" in my Freya and they sound great and seem utterly neutral...like little glowing Switzerlands. The impact of any tube tone in a Freya can easily be noted by switching to the passive mode and comparing the two...adjusting for gain of course. Also, based on close to a year of use with various tubes, I'll say again that the Freya is a steal in today's audio world and would be worth it at twice its price.