How to determine Mullard GZ34 date of manufacture

Tubes Asylum

Questions about tubes and gear that glows. FAQ

12.78.46.62

MarkLang

Hello,
Is there a way to determine the manufacture date of Mullard 5AR4's (GZ34's)? The code on them is f31 B9L.
Thanks

This post is made possible by the generous support of people like you and our sponsors:

Michael Percy Audio

Topic - How to determine Mullard GZ34 date of manufacture - MarkLang 21:22:14 04/07/07 (3)

Link to code decipher - Ron Oehlert 12:51:26 04/09/07 (1)

Duh..... - Sherlock 18:25:31 04/09/07 (0)

Re: How to determine Mullard GZ34 date of manufacture - tvad 22:18:59 04/07/07 (0)

You can not post to an archived thread.