> If the capacitors were low inductance chips mounted directly
> between the socket and chassis, it would be another story. But
> adding any long thin leads to the grid is generally a bad idea,
> whether in series with a capacitor or not.
>
> The capacitors are just a poor idea that made it into many
> amplifiers because no one checked the effects thoroughly.
> 73, Tom W8JI
> w8ji@contesting.com
>
As I told in my message, all depends by the tube and its socket.
When a tube socket is mechanically unsuitable for short, low inductance
ground connection, or inside the tube itself there's a long lead
(inductance) to reach the grid, there's practically no difference if
the "bridge" from socket pin to the ground is made with a bare wire or
using a proper capacitor with short leads involving the same total
lenght, and probably a larger equivalent diameter, of a wire jumper.
It remains the fact that DC grounding grid with a bare wire or a strap
in SB220 and TL922 without adding a proper circuit for protection is
not the safest procedure and doesn't enhance anything in practice about
gain and stability.
73,
Mauri I4JMY
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