For sale is an Amperex Orange Globe branded 12au7 / ECC82 tube.  This tube was actually made in Great Britain by Mullard at the Blackburn facility; a GF2 series tube, date code B1K1 .   This tube is in excellent operating condition, measuring nearly NOS and tightly matched on both plates.  This tube has the Mullard tone and color that they are know for, and was not microphonic in my preamp.  The only downside is the lettering is quite fragile and has rubbed off significantly, this doesn't effect its beautiful sound however.  Comes with original box in good condition and will be carefully package and shipped to its next happy owner.