Any particular tube is going to sound slightly different depending on the amp in which it’s installed. Some of the best advice I’ve been given in this hobby is to buy NOS tubes from Andy at Vintage Tube Services. Spend a little more $ now to get tubes that can possibly outlast you and perform better than any of these new production Chinese/Russian tubes.
Preamp tube
Any suggestions, I’m considering changing the V1 preamp tubes (12AX7/ECC83) on my Jolida 1000 integrated amp. Right now I am using Genalex Gold Lion’s. Any thoughts and what the benefit will be from the suggestion?