You only need to replace the pair of 6922 that is closest to the rear end.
These positions generates 100% change in sound.
My Line 3 has been upgraded to SE.
In my system I have found these tubes to generate the best sounding music from my Line 3:
Amperex 6922 PW 1960 production
Siemens CCa 1958 production
Valo E88CC production 7LH 482 Kevin Deal
Ediswan 2492 KB/AD and CV5358 Kevin Deal
Amprex 6922 white label
Hope this helps. Terry
These positions generates 100% change in sound.
My Line 3 has been upgraded to SE.
In my system I have found these tubes to generate the best sounding music from my Line 3:
Amperex 6922 PW 1960 production
Siemens CCa 1958 production
Valo E88CC production 7LH 482 Kevin Deal
Ediswan 2492 KB/AD and CV5358 Kevin Deal
Amprex 6922 white label
Hope this helps. Terry