I've had no problems with Gold Lion 5AR4s, but I would use what the manufacturer recommends. A friend of mine continually rolls tubes and has managed to trash a number of expensive amps. The manufacturer of one amp specifically advised against using a certain brand of 300B. He did anyway and blew the amp--twice!!
5ar4 rectifier tube
I’m buying some backup 5ar4’s for my primaluna evo 100 preamp. Upscale audio’s website says the Gold Lion isn’t suitable for this preamp. I like Gold Lion but there’s no explanation why. There’s only one other choice on their site. I also like Upscale audio. Advise is appreciated..