Can a 6SQ7 metal tube be used to replace a 6SQ7 glass tube? I thought 'GT' meant glass tube. My tube supplier only has metal 6SQ7 tubes. Thanks.
-Bill

:Can a 6SQ7 metal tube be used to replace a 6SQ7 glass tube? I thought 'GT' meant glass tube. My tube supplier only has metal 6SQ7 tubes. Thanks.
: -Bill
:
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Yes, provided that pin 1 of the tube's socket is either grounded or has no connection to it. Metal tubes use pin 1 as a ground connection for the metal case; so sets originally designed for metal tubes have this pin grounded. Other sets that were designed for "G" glass-bottle tubes often left this pin ungrounded or, worse yet, used it as a tie point to connect unrelated components.

A metal tube will do the same thing as the glass one. But check the connection to Pin 1 - it is connected to the metal shell, so Pin 1 can be connected to chassis ground, but shouldn't be used as a tie point for anything else.

:A metal tube will do the same thing as the glass one. But check the connection to Pin 1 - it is connected to the metal shell, so Pin 1 can be connected to chassis ground, but shouldn't be used as a tie point for anything else.

Thanks for the feedback !
-Bill