The AM Forum

Came across this Mullard 12ax7 ECC83 in my NC-303, Q Multiplier tube, and was curious about it. It appears to be an original, non-reissue, due to the mold marks in the glass at the top (can kind of see them in the photos), but I cant fins any images online that look exactly like this tube. Were there many variants? Were there fakes? I know that some of these can be worth some money and can be pretty rare, which is why I took it out of the 303 and replaced it with a NOS RCA Black Plate 12ax7. And also, what is the significance of the numbers "1.11.6." on the one side? Batch number?

Thanks!

Perry
W3MMR

Marshall guitar amp owners LOVE that type of  tube .... most likely OEM

n.b.   put it on Epay with some evidence of goodness and be surprised just how high the bidding can go  :o :o

Better late than never I suppose from a hollow state man in a solid state world. I get a bit of a giggle out of that reply, musicians and audiophools love the mystique of British valves that in reality are simply equivalent to American tubes, there is NO difference. If you want tubes with a difference, use broadcast and industrial types such as the 7025 low hum and noise twin triode, a 12AX7/ECC83 in disguise. Then there is the 6146W "ruggedized" 6146 and the 6146B that the Yeasu FT-101 series hates, mind your interelectrode capacitances, but I digress.

Now finally to the point, back in the day American meant all American, the original tube(s) was were American, in this case a plain old 12AX7. Somebody stuck that ECC83 in there because it looked cool until the lid was closed. (;->) I leave you tube affectionados such as I with this to watch: https://www.youtube.com/watch?v=-GgWIlvyEL8 an interesting video on how receiving valves were made by (not as tiny as Asian) dainty British women's fingers.