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Mystery 12ax7s!!! What could they be???

Posted: Tue Nov 22, 2011 11:30 am
by TommyShameless
I have these...I don't know what they are, since they aren't labeled. Anyone care to take a guess?

They say 163, and B7L1.

What do we have here?

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Tommy

Re: Mystery 12ax7s!!! What could they be???

Posted: Tue Nov 22, 2011 11:42 am
by stef
I had 3 of those too, used and almost dead. No idea what they are. Sounded pretty good before they started to make cranking and popping sounds.

Re: Mystery 12ax7s!!! What could they be???

Posted: Wed Nov 23, 2011 7:05 am
by demonufo
That's I63 and they're Blackburn Mullards.

Re: Mystery 12ax7s!!! What could they be???

Posted: Wed Nov 23, 2011 8:36 am
by TommyShameless
So, wow! So these are pretty sweet, then!