Pass Labs XA60.8

[Elk]

BHK Signature 250 or 300 Tube Rolling

I understand PS Audio’s tube selection is limited to new tubes. I, however, just purchased three different sets of quads: (1) Siemens ECC88 (6DJ8); (2) Amperex 6922 (Holland) and (3) Amperex ECC88 Bugle Boys with the Halo Getter. Does anyone have experience with these tubes? How long do you have to burn in a tube before listening to them to determine which ones sound better? Any other thoughts on tube rolling? Mark