I use these voltage regulator tubes in my Croft preamp, and I've been wanting this one for a while, as it's a special (and rare) military spec version, from the 1950s, of the 85A2:





I've rolled these VR tubes before, and the best ones always make a nice difference, so will be interesting hearing what this one does!

For the Croft's line stage, I've also just bought a rather nice matched Pair of 1940s Raytheon 6SL7GTs in gray glass:



Looking forward to hearing those, too!

Marco.