Lightly used, like new Rare 1960s BRIMAR 13D9 Industrial grade with Black Plate and Copper Grid Posts  with BVA logo. 13D9 is a Special Grade Variant of CV4024/ECC81/12AT7 valves. STC Rochester Plant Date Codes are faint and painted on instead of etching in 13D9, and may not be visible on all tubes. Packed in generic white boxes.

Labels are fragile and not perfect as chalky printing from 1960s comes of easily with contact. In our opinion, 13D9 Brimars are better than 6060/CV4024 that look similar and sonically at par with Brimar CV4033.

Tested and matched on Hickok 752, just recently calibrated and modified by Hickok expert to all Solid State to eliminate drift. However, on average 12AT7 measures lower on this 752 than it should.

For comparison, 12AT7 measuring 4400-4400 on calibrated Hickok 600 measures 3300-3300 mmhos on this 752. Average new 12AT7 on Hickok 600 is 4000 mmhos. In other words, actual test scores are higher than what we have noted on the tube boxes.

Single Tube = $35. Select 2 for a Matched Pair or 4 for a Matched Quad. Even odd number of tubes will be matched.