Tube rolling a Demeter VTBP-M-800D

[Coolhandjjl]

Like the title reads, any one opened 'er up yet and tried some out?

Stock, mine has an EH 12AX7 in the left, a JJ ECC81 (12AT7) in the right slot. I do know that ECC81s are 60mU.

I have some NOS tubes, a GE black-plate 5751, those are 80mU; and some Mullard Blackburn long-plates ECC83s, 100mU.

I wonder if I will fry anything putting a higher gain tube in the right slot?

 

[B-string]

You won't "fry" anything. Keep in mind the 12AT7 is a higher current device than the 12AX7xxx. If the 12AT7 is in a buffer (output) circuit a sub for the higher current lower gain 12AU7 would be the choice.