Matched Pair New Old Stock Mullard Master 10M Series 12AU7A Vacuum Tubes (Item: RDW-510)

Closely matched pair of the highly sought after and rare Mullard "Master 10M Series" 12AU7A twin triode vacuum tubes with gold pins in original boxes. Made in Great Britain and sold by IEC. Both have the same date and production codes. One tube tests 2584/2736 uMhos (baseline 1900 uMhos) and the other tests 2662/2736 uMhos. Tested on Hickok AN/USM-118B tube tester. Note: Tube labeling is a bit faded-see pictures.