Yesterday I picked up a Cary 303/300 CD player. The seller handed me a small bag of "surplus" tubes for it. The stock tubes are Electro Harmonix. In the bag was:
A pair of RCA 12AU7
A Pair of Philips ECC82
a Pair of Groove Tubes 12AU7
Are any of these what one would call standout? My amp uses 3 12AU7s in the driver stage so I might have an opportunity to do a bit of rolling
Here's the photos of them. Only one of each is shown and the EH are currently installed in the player.