NATIONAL UNION 50 — Matched Pair Vintage Power Triodes
Grade: Gold Series
Laboratory Verified
Laboratory Verified
Matched Pair (2 Pcs)
Black Plate & Black Base
Made in USAAmplitrex AT1000 Verified
Black Plate & Black Base
Made in USAAmplitrex AT1000 Verified
Up for sale is a rare, laboratory-matched pair of 2 pieces premium National Union 50 power triodes. These iconic American-made tubes feature the classic Black Plate construction and sturdy Black Bases, housed in clean white replacement boxes.
This pair has been precision-tested and matched on the Amplitrex AT1000 professional analyzer. Finding a pair of Type 50 tubes with identical test results (Plate Current and Transconductance) is exceptionally difficult. These units test well above original factory specifications, making them a “Holy Grail” choice for high-end single-ended triode (SET) audio amplifiers where perfect channel balance is critical.
| Serial No. | Test Triode | Parameter Ip mAdc | Result Ip mAdc | % Ip | Parameter Gm uMhos | Result Gm uMhos | % Gm |
|---|---|---|---|---|---|---|---|
| 917003 | Triode 1 | 55.0 | 67.0 | 121.8% | 2100 | 2820 | 134.3% |
| 917004 | Triode 2 | 55.0 | 67.0 | 121.8% | 2100 | 2820 | 134.3% |
Note: Custom duties and taxes are the responsibility of the buyer in their country.
Reviews
There are no reviews yet