TOSHIBA 12BH7A – MATCHED PAIR (2 PCS)
Black Plate
Top Ring Getter
Made in Japan
Medium-Mu Power Dual Triode 12BH7A / 12BH7
New in Original Box
Amplitrex AT1000 Tested
Up for sale is a matched pair (2 pcs) of genuine vintage NOS Toshiba 12BH7A medium-mu dual power triode vacuum tubes, manufactured in Japan (Tokyo Shibaura Electric Co., Ltd.) and complete with their original Toshiba boxes. Renowned for their ultra-clean signal reproduction, wide dynamic headroom, and smooth high-end resolution, these Japanese vintage classics feature long black plates and top ring getter structures. An outstanding choice for high-end audio preamps, driver stages, OTL headphone amplifiers, and guitar amplifiers requiring 12BH7 / 12BH7A series tubes.
Both tubes have been fully tested on a precision Amplitrex AT1000 tube tester. Measured Plate Current (Ip in mA) and Mutual Conductance (uMhos) alongside percentage performance ratings relative to nominal factory reference specs (Reference: 11.5 mA / 3,100 uMhos) are detailed in the table below.
| Serial No. | Triode Section | Plate Current (Ip) | Mutual Conductance (uMhos) | ||||
|---|---|---|---|---|---|---|---|
| Ref Spec | Result | % Ip | Ref Spec | Result | % uMhos | ||
| SR.NO.3051008 | Triode 1 (T1) | 11.5 mA | 10.0 mA | 87% | 3100 | 3000 | 97% |
| Triode 2 (T2) | 11.5 mA | 6.8 mA | 59% | 3100 | 2500 | 81% | |
| SR.NO.3051003 | Triode 1 (T1) | 11.5 mA | 8.0 mA | 70% | 3100 | 2380 | 77% |
| Triode 2 (T2) | 11.5 mA | 11.2 mA | 97% | 3100 | 3230 | 104% | |
Technical Note: Custom duties and taxes are the responsibility of the buyer in their country.
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