In my amp the rectifier, it can take either a 5AR4 or 5U4G, makes a huge difference in sound quality. I rotate different ones in from time to time they seem to last pretty long at least 2 years for me and I listen constantly. I will also say a 5U4G sounds much better than a 5AR4 to me.
Reminder - It might be time to replace the rectifier tube if you have one.
Having owned tube components for many years, I’m used to replacing tired valves. Usually, weakening dynamics are the first indication. Three years ago, I purchased a DAC that has tube output stages and a tube rectifier. The dealer didn’t how long the rectifier life was. He just said ’a long time’. Last week, I replaced it with the same NOS brand/model - different year of manufacture.
The old one was quiet, nice tone, excellent dynamics - along with a fairly forward & lush presentation. The fresh replacement was very similar but with a much deeper/wider sound-stage. Instead of forward & lush, the image was cleaner with more instrument separation. The dynamics were pretty much the same. I’m pleased that the rectifier had a 3 year life-span.
The old one was quiet, nice tone, excellent dynamics - along with a fairly forward & lush presentation. The fresh replacement was very similar but with a much deeper/wider sound-stage. Instead of forward & lush, the image was cleaner with more instrument separation. The dynamics were pretty much the same. I’m pleased that the rectifier had a 3 year life-span.