https://pulsetubestore.com/(NOT MADE IN CHINA)
IF Out of Stock on this site, you can order these factory direct at pulsetubestore.com. Click on the above banner.
NOTE: After spending $$$$ on tooling and various prototypes, we have fitted Special Grade Flying Leads tubes with Custom Bakelite Bases developed in-house. It is a multi-step, labor intensive process. Each lead is straightened and cleaned to ensure perfect fusion with the base pins in the soldering bath. Process is painstakingly slow, so we will be adding a few tubes at a time to the inventory.
Tubes are Plug & Play, Ready to Use, fitted with our Custom made Bakelite Bases (INTL Patent Application in Process).
Brand New MINT NOS Rare 1960-62 BRIMAR CV4033 Black Plate with Copper Grid Post Military tubes. Factory tested and serialized*. CV4033 Flying Lead is a Premium Grade, High Reliability Long Life version of CV4024/ECC81/12AT7 valves
). CV4033 premium grade version of the 1960s Black Plate CV4024/6060 is one of the best from Brimar in the ECC81 types.
STC Rochester Plant Date Codes. Made in England. Packed in generic white boxes from bulk.*From 100 pc bulk boxes, each tube came with two factory stickers (click Larger Photo). A hand written individual serial number on top, and a printed sticker with numbers R811451 PM25525-1 on the side. Tubes were factory tested and serialized for some qualification (R811451 PM25525-1), except we don't have specific details of the qualification.
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 = $45. Select 2 for a Matched Pair or 4 for a Matched Quad. Even odd number of tubes will be matched.