Just after some anecdotes and thoughts on tube rolling effects in a phono stage please guys.
After great results putting classic valves like Telefunkens and Mullards in my Quintet valve amp my own thoughts have turned to what possible gains can be had by "upgrading" the valves in my phono stage, an Art Audio Vinyl One Reference. As standard these are fitted with Sovtek 12AX7s and a Silvania 6FQ7 rectifier, and while I had no complains whatsoever with them I didn't know how long they had been in there when I purchased it so I thought it wouldn't hurt to change them.
Now I don't have a lot of experience with valves in particular & hi fi equipment in general, and when reading up and trying to learn I couldn't see how changing a rectifier valve could alter the sound, but change it I did, for a NOS General Electric 6FQ7, and expectation bias aside the sound was different right from the off.
I had spent an hour listening to tracks I knew well, but now they sounded cleaner, even louder, bass seemed more defined, wind instruments seemed more "reedy", the old cliche of "blacker blacks & higher highs" came to my mind. May be the old valve was way past it's best and this accounted for what I could hear, but I hadn't heard any signs of this previously.
Now I am not talking night and day differences you understand, just a bit more of everything, and it already sounded great to me. I understand a valve with higher gain could be responsible for it sounding louder, but it was a like for like swap, just a different manufacturer.
Does anyone have any similar experiences, even those which would contradict my own?