NOS Philips Miniwatt 12AX7 / ECC83 | Mullard Blackburn B Code | Kalibr L3-3
NOS Philips Miniwatt 12AX7 / ECC83 | Mullard Blackburn B 코드 | Kalibr L3-3
| 상품번호 | 198401992650 |
| 상태 | Open box |
| 거래유형 | 즉시구매 |
| 출고국 | 미국 (US) |
상품 설명
Professional Tube Laboratory Test Report
Every tube listed in my shop undergoes a rigorous testing procedure to ensure the highest fidelity and performance for your equipment.
- Testing Equipment: Professional Kalibr L3-3 Tube Tester.
- Precision Measurement: Measurements are verified using a calibrated Metrix MX 51EX digital multimeter.
- Transparency: All results are provided in the product photos, displaying specific Anode Current (Ia) and Transconductance (S) values compared to manufacturer specifications.
For sale is a premium, vintage Philips Miniwatt 12AX7 / ECC83 dual triode tube (Internal Reference: TG2E4L). This specific unit features the highly collectible yellow and blue star shield label (B10 marking) and is in immaculate, pristine NOS condition.
The Ultimate British Pedigree (Mullard Blackburn)
While branded Philips, this tube features the historical etched production codes on the glass showing the B factory code. This confirms beyond doubt that it was manufactured in Great Britain at the legendary Mullard factory in Blackburn. It features the highly sought-after vintage construction known for its warm, lush midrange, deep bass, and legendary musicality.
This tube is in genuine NOS / Test New condition, displaying a virtually perfect balance between both internal triode sections. It has been thoroughly laboratory-tested on our professional, calibrated Kalibr L3-3 tube tester.
Key Features
- Brand / Label: Philips Miniwatt (Rare Yellow & Blue Star Shield Emblem)
- Actual Manufacturer: Mullard Blackburn (Genuine Etched
BCode) - Type: 12AX7 / ECC83 / 12AX7S
- Design: Short Gray Plates / Halo Getter
- Condition: Genuine NOS / Test New (Incredibly close to 100% factory specifications)
- Balance: Exceptionally Matched Triodes (Identical 1.15 mA Anode current matching)
- Safety: Strictly tested, NO shorts, perfect insulation.
Detailed Test Results (Kalibr L3-3)
Tested under reference conditions: Uh 12.6V / Uc1 -2V / Va 250V
(Factory Spec for 100% brand new tube is Ia = 1.2 mA / S = 1.6 mA/V)
• Anode Current (Ia): 1.15 mA (95.7% of factory spec)
• Transconductance (S): 1.57 mA/V (97.9% of factory spec)
• Anode Current (Ia): 1.15 mA (95.5% of factory spec)
• Transconductance (S): 1.64 mA/V (102.8% of factory spec)
🌟 Note on Matching: An anode current (Ia) measurement of 1.15 mA on BOTH sections represents a flawless balance between Triode 1 and Triode 2. Combined with strong transconductance (S) tracking tightly around the 100% mark, this tube delivers optimal symmetry for high-end audio stages and hi-fi preamplifiers.
Structural & Safety Tests Passed
- Insulation test between Cathode (k) and Heater (H): PASSED (No leakage)
- Insulation test between Cathode (k) and Grid 1 (g1): PASSED (No shorts)
- Insulation test between Grid 2 (g2) and Grid 1 (g1): PASSED (No shorts)
About our testing methodology
To provide full transparency, our laboratory testing uses a professional Kalibr L3-3 tube tester. Since this device uses specific internal scales rather than direct mA/V readouts, each value is physically calculated to ensure precision.
- Example of our calculation (Transconductance S):
Using a raw Kalibr reading of 78.3 on a standard scale of 150 with a multiplier of 3.0:
(78.3 x 3.0) / 150 = 1.57 mA/V - Percentage vs. Factory Specs:
We then benchmark this result against the factory nominal value for a new tube (e.g., 1.60 mA/V for a 12AX7):
(1.57 / 1.60) x 100 = 97.9% of factory specification.
Worldwide shipping with bulletproof packaging. Tracking number provided immediately.