BRIMAR CV4003 / 12AU7WA / 6189 — Matched Pair 2 Pcs
Made in England
Grey Plate
Early 1960’s Production
New in Original GVT Box
Amplitrex Tested
Available for Sale is a premium, matched pair (2 pieces) of highly ruggedized Brimar CV4003 / 12AU7WA / 6189 dual triodes. These are authentic British military-grade valves manufactured in the early 1960s, bearing the coveted KB/AD government specification mark. They feature robust Grey Plates and a stable Top Ring Getter structure.
These valves are New in Original GVT (Government) Boxes and have been fully evaluated on our laboratory-grade Amplitrex AT1000 tester to ensure perfect performance percentages against standard factory parameters.
| Serial No. | Test Triode | Parameter Ip mAdc | Result Ip mAdc | % Ip | Parameter Gm uMhos | Result Gm uMhos | % Gm |
|---|---|---|---|---|---|---|---|
| 802437 | T1 | 10.5 | 10.6 | 101.00% | 2200 | 2200 | 100.00% |
| T2 | 10.5 | 10.2 | 97.10% | 2200 | 2200 | 100.00% | |
| 802725 | T1 | 10.5 | 10.4 | 99.04% | 2200 | 2200 | 100.00% |
| T2 | 10.5 | 10.2 | 97.10% | 2200 | 2200 | 100.00% |
Platinum Grade Matching & Genuine Tolerance Analysis
- Internal Section Balance (T1 vs. T2): There is a 3.9% difference in Plate Current (Ip) between the two triodes.
- Transconductance (Gm) Accuracy: Both triodes are at exactly 100% of the target 2200 uMhos parameter.
- Overall Health: This tube is perfectly balanced and operating at full original factory specifications.
- Internal Section Balance (T1 vs. T2): This tube shows a 1.94% difference in Plate Current (Ip), which is nearly perfect matching.
- Transconductance (Gm) Accuracy: Both triodes are at exactly 100% of the target 2200 uMhos parameter.
- Overall Health: This tube is slightly more balanced internally than the first, but still sits at 100% life.
🤝 Platinum Match Verdict: Both tubes stay strictly within a ultra-tight <5% tolerance threshold for both internal section balance and tube-to-tube matching.
About NOS Audio Tubes
We are professional specialists in high-quality vacuum tubes with industry roots dating back to the 1970s. With an inventory of approximately 300,000 valves, we utilize industrial-grade Amplitrex AT1000 equipment to provide accurate, transparent test data for audiophiles worldwide.
Note: Custom duties and Taxes are the Responsibility of the Buyer in their Country.
NOTE : WE HAVE MORE THAN 1000 PCS
Support: [email protected]
NOS Audio Tubes — Mumbai, India
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