Same amplifier !  Different tube !   Different voice !
Trying different voice by tube with adapter. Needn't change amplifier anything.
Just connect tube and the adapter.
Top is 5687
Bottom is 6N6 6N2 ECC88 6922 6DJ8 ECC85 6N11
Top ceramic socket with gold pin for long life
Bottom strong thick gold-plated tube pin
Amplifier design use 6N6 6N2 ECC88 6922 6DJ8 ECC85 6N11
If want to try 5687,Only plug it into the adapter
Then plug into amplifier,begin to enjoy music
Needn't change amplifier anything