I must confess that I’ve had 3 Cary SLP-05 and I’ve tried many tubes and the ultimate upgrade version and I always felt it was lacking something. Tube list that I tried listed below.
Melz 1578
Sylvania VT-231 & 6SN7W
Sophia Blue Glass 6SNGT
PSvane CV-181II
CBS/Hytron 5692
LianLa Elite 6SN7
KenRad VT-231
Pope 6SN7GT
EH -6SN7
Ok maybe a few more but they never hit the nerve!