[Captainhemo]

Hi Guys
I'm  not famaliar with the early Mullards at all. I had this Mullard 12AX7 given to me and was wondering if it is what they call a box plate  ?
There is not  many markings left on it,  a bit of the Mullard logo is visible and the odd digit/letter but not much.



Too bad  I only  have  the one , would have  liked to hav given a pair a try

-jay

[Ericus Rex]

Don't fret Jay.  Many tube sellers will accept your single, test it and see if they have a suitable match in their stocks.  Do expect them to charge a fee for this in addition to the cost of the matching tube.

[Adriano]

I think this is a Mullard 17mm long plate round getter ecc83, not a box plate, all box plate have a shorter plate even with square getter.


Left: Mullard 1959 long plate single support round getter ecc83
Right: Mullard 1958-1959 january long plate double support round getter ecc83

[Adriano]

Mullard box plate square getter ecc83/CV4004 mid 1950s

[Captainhemo]

Thanks for the replies you  guys and  also for the reference pics ,   handy.

I loooked at the tubes again that I was given  and  there is also this one which  appears to be almost identical but it has absolutely  no labeling left on it.  Both the tubes  have the same plates and both have a halo/ring getter with a single support.  Both tubes also have the  "X" seam on top.   The 2nd one seems to have a slightly different bevel on the top  where the  top of the tube meets the  tip, but they are very close
All I have for a tester is an  old EMC 213-215.... Both these tubes have no shots and  on the quality test,  both sections in  both tubes come out between  35-36.   Not great  but both well  into the  "good range"  on the tester.



Both appear to be the Mullard ECC83  long plate so maybe I already  have  a match ?

Tube ID'ing is so touogh once the labels dissappear  and you  are just learning the basics

-jay