Internal shield on 6922 dual triode

[zigzagflux]

Quick question, I assume the answer to be somewhat obvious:

Using three 6922's in cascode for stereo amp input. One is left/right input tube, near circuit common potential.

Second tube is left upper tube of the cascode and cathodyne splitter.

Third tube is right upper tube of cascode and cathodyne splitter.

I preferred this arrangement, as I am elevating the heater voltage above common for the two tubes.

Anyway, question is, do I ground the internal shields of all the tubes, even those with elevated potentials? It would definitely limit capacitance from triode-to-triode. Don't know if there are any limiting voltage factors to consider, or what the real benefit is when each triode is NOT upper/lower, but both are near the same circuit potential.

My first thought was to tie all shields to frame, as opposed to circuit common. It is likely my circuit common will tie to frame through a 100-1K resistor.

Experiences?

[Eli Duttman]

Dig up a Philips data sheet for the ECC88/6DJ8. You will get info. about which section goes on the top of a cascode. It matters.

Grounding pin 9 of each bottle to the chassis near the sockets should be fine.



Edit: fixed typo