I have seen that table as well.
I am not sure what to do with the plate voltage KT 66 and 88 which are listed as up or down. Is it try and see how it sounds?
Leben CS 600 tube rolling
I am thinking of trying a new set of power tubes in my Leben cs600. As the NOS EL 34 and 6L6 are drying up ( or getting too expensive ) I thought I would try new production KT 66 ot KT 88. In part just for fun and to check out a different sound.
I have the output tube compatibility settings chart for Leben.
For the KT 66 and 88, under the plate voltage column, they have a delta sign. I am not sure what that means?
Has anyone tried these alternate tubes?
Thanks
MP