Elekit 8600S tube rolling question

[JadedPhishFan]

Without modification would it be possible for me to roll in some of my vintage 6CG7/6FQ7 tubes instead of 12AU7s?

 

[rayma]

The heater voltages are different, so no it won't work at all.
6FQ7 = 6V heater (pins 4-5)
12AU& = 12V heater (pins 4-5)

The 12AU7 can be configured to work on 6V, but the heater pinout would be different.
Short pins 4-5 for one terminal of the filament supply. Connect the other supply lead
to pin 9, which is the filament center tap. Now the two halves are in parallel, for 6V.

 

[JadedPhishFan]

Thanks for feedback ... would've loved to use my Mazda 6FQ7s but guess it'll be for another project

 

[paczeltf]

Without modification would it be possible for me to roll in some of my vintage 6CG7/6FQ7 tubes instead of 12AU7s?

You can buy a pair of cheap socket converters, but the real issue is that the 6CG7 draws twice the heater current, which in not something the amp will tolerate well without modifications.