Congrats Glory! I have the Zu Definitions and use M60's. You are going to love the S-30!
In the past I've tried older (1950's) NOS Sylvania and RCA, preferring RCA's in the top and bottom half of the cascode voltage amp positions (V2,V1 respectively). These are the two most sensitive positions to affect sound.
Don't even bother spending good money on the constant current source tube (V3); I've never noticed a difference in this tube.
The 3rd most sensitive position is the output section driver tube (V4). This must be a GTB or GTA tube due to higher voltage. I have noticed an improvement with old (1950's) Sylvania GTB's here, but it would be the last place I'd upgrade. Talk with Andy and Vintage Tube Services...he's very helpful.
Good luck and enjoy!!
Jordan
In the past I've tried older (1950's) NOS Sylvania and RCA, preferring RCA's in the top and bottom half of the cascode voltage amp positions (V2,V1 respectively). These are the two most sensitive positions to affect sound.
Don't even bother spending good money on the constant current source tube (V3); I've never noticed a difference in this tube.
The 3rd most sensitive position is the output section driver tube (V4). This must be a GTB or GTA tube due to higher voltage. I have noticed an improvement with old (1950's) Sylvania GTB's here, but it would be the last place I'd upgrade. Talk with Andy and Vintage Tube Services...he's very helpful.
Good luck and enjoy!!
Jordan