Matching preamp tubes is NOT essential, only when it comes to power tubes. but guess what?? ALL tubes drift so its "never" really matched (except at the beginning) but its always a good starting point.
Replaced stock McIntosh 12ax7a with gold lion ecc8
I replaced the stock tubes in my c500t which are about 2 years old with new Gold lion ECC83's and I noticed that the tubes are not lighting up hardly at all compared with the stock tube. could this be a Bias issue? The sound is different as I would expect. Bass is more round, maybee a little heavier (good for my system) Imaging is more diffuse not as spot on as I have had. They are new so some break-in is needed. Any thoughts or experiences?