Chinese 12AX7 Cathode Follower?

[paddy]

Hi Guys,

Does anyone know if the chinese 12AX7-C9's have a spiral filament?
I want to use one as a cathode follower, where the voltage on the
cathode is fairly high.

Cheers,
Paddy

[Gaz]

No spiral filament. If it's your own amp, or not super valuable, you should really elevate the heaters with a filter DC voltage, which helps with heater hum in addition to taking care of the heater to cathode issue.

[paddy]

Hi Gaz,

Thanks for the info. Will try elevating the heaters if hum is an issue.

Cheers,
Paddy