They are tested NOS, balanced tightly matched on my TV-7/U and sound wonderful on my hifi system. These tubes can be used in plcae of 12AU7 or 6072 which upgrades your system to the next level. They are deadly quiet with very harmonic sounding quality.
SOLD FOR PARTS or Repair. Not sure of the date of the unit maybe 1970's????.
READINGS CAN BE SEEN IN THE PHOTOS. WHAT'S INCLUDED IN THE SALE: You will only receive what is shown in the photographs. If you do not see it in the photos, it is likely not included in the sale.
Beautiful pair of Brimar 12AT7/ECC81 black plate tubes, with original boxes. Strong testing and Gm matched to about 14% difference. Tested quiet on the Amplitrex AT1000. Both have Brimar's characteristic etched codes, but they are difficult to make out.