ECC81 MULLARD 10M SERIES. 10M IEC TOOK THESE VALVES FROM MULLARD, TESTED THEM AND GOLD PLATED THE PINS AND ENSURED RELIABILITY FOR 10,000 HOURS. MULLARD CONSTRUCTION MAY VARY FROM TUBE TO TUBE. THE TUBE WE OPENED TESTED 110% AND WAS A SQUARE GETTER MULLARD FROM THE 60’S.
