I have a near 25 year old Audio Research pre-amp that came new tubed with Chinese 6DJ8. I liked the sound quite a bit and decided after a few years to experiment with tubes. Holland, Bugle Boys, Amperex and so on came and went. ..many different manufacture countries and brands rolled in and rolled out, until I encountered a Siemens & Halske 6922 grey plate from the late 50's - early 60's. That was the tube of choice for more than decade until I tried a 1959 Valvo Pinched Waist 6922 Cca, which was great for about 2 years of light use when it began to fade musically. Now it's a 1975 silver single wire Reflector 6N23 which is king of the hill.
The point being the right tube(s) can make or break your sound. Do some tube rolling. What doesn't work for you can probably sell easily on eBay.
The point being the right tube(s) can make or break your sound. Do some tube rolling. What doesn't work for you can probably sell easily on eBay.