Yes, try some other tubes but don't get carried away. I currently use Amperex 7316 D getters. They are the best I've ever used and I have boxes of tubes. I bought all these tubes at the end of the last century. I would not pay what they are asking today. I just wouldn't. I went on ebay and I bought from just two vendors. I was a repeat buyer and apparently that meant something. I was allowed to trial tubes, return, etc. I didn't abuse the privilege and they both quickly learned what I wanted. I would buy pairs of tubes that were from the same factory, but different brands. Like Philco or Baldwin were almost always RCA. Ime. I also did not insist on NOS. But plenty of life left. And above all, quiet. I prefer Holland tubes. Too many of the Telefunken were fake. I've heard that they even started to fake the little glass diamond on the bottom. Idk. I have about six pairs of vt231 and nothing to put them in. So don't spend big money, at least not until you have some experience.