NOS Dario Miniwatt 12AX7S Tube | Ultra Rare French RT Chartres FRS 1960s | Kalib
NOS Dario Miniwatt 12AX7S 진공관 | 초희귀 프랑스 RT Chartres FRS 1960년대 | Kalib
| 상품번호 | 198433469210 |
| 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 an ultra-premium, highly prized vintage Dario Miniwatt 12AX7S dual triode tube (Internal Reference: TGGJGP) in New Old Stock condition. This unit features the iconic green brand logo beautifully preserved on the glass.
The Elite French RT Chartres Heritage (Ruggedized 'S' Spec)
The 12AX7S designation represents the absolute pinnacle of premium European tube engineering by La Radiotechnique (RT), a premium subsidiary of the Philips group. The "S" denotes a specialized, high-security structural design featuring premium grid alignment and heavy-duty internal construction. It is globally famous for delivering an ultra-silent background, high anti-microphonic properties, and an exceptionally sweet, transparent musical character.
- Authentic Physical Etched Code: The lower portion of the glass features the permanent factory contract and batch identification etched code:
12AX7S.FRS.62272(confirming production at the elite RT factory in Chartres, France). - Premium Audio Grade Selection: This specimen showcases an incredible structural vitality and very tight triode tracking, making it an absolute reference upgrade for elite preamplifiers or legendary guitar tube circuits.
This unit comes preserved in its original vintage Dario Miniwatt cardboard box in good vintage condition showing authentic age wear and has been thoroughly bench-tested and audited on our professional, calibrated laboratory-grade Kalibr L3-3 tube tester.
Key Features
- Brand / Label: Dario Miniwatt (Classic Green Imprint)
- Designation: 12AX7S (Premium Low-Noise / Low-Hum version of 12AX7 / ECC83)
- Provenance: Genuine French Production (Etched FRS Chartres Code)
- Design: Short Dark Gray Plates / Sturdy Double Mica Support / Halo Getter
- Condition: Genuine Vintage NOS / Test Strong (Solid, balanced electrical output)
- Packaging: Complete with its original vintage Dario Miniwatt cardboard box (Authentic age/shelf wear)
- Safety: Strictly lab-tested, NO shorts, perfect internal insulation.
Detailed Test Results (Kalibr L3-3)
Tested under reference laboratory conditions: Heater Voltage (Uh) 12.60 V | Grid 1 Voltage (Uc1) -2 V | Anode Voltage (Ua) 250 V
(Factory specification for a 100% brand new reference tube: Ia = 1.20 mA / S = 1.60 mA/V)
• Anode Current (Ia): 0.85 mA (71.2% of factory spec)
• Transconductance (S): 1.34 mA/V (84.0% of factory spec)
• Anode Current (Ia): 0.95 mA (79.0% of factory spec)
• Transconductance (S): 1.45 mA/V (90.9% of factory spec)
🌟 Seller Note on Performance: This vintage 12AX7S behaves beautifully under stress. While the static current shows a gentle vintage character, the most crucial dynamic measurement—the mutual transconductance (S) gain—tracks at an excellent and strong level of 1.34 mA/V and 1.45 mA/V (up to 90.9% of factory new spec). This ensures great dynamic punch, pristine linearity, and superb signal uniformity. It is a marvelous drop-in upgrade to transfigure the high-gain input stage (V1) of boutique guitar amplifiers or the phono/line stage of high-end Hi-Fi gear with that distinct, silky French vintage soundstage.
Structural & Insulation Tests Passed
- Grid 1 / Cathode 1 Insulation: PASSED (No leakage / No shorts)
- Anode 1 / Cathode 1 Insulation: PASSED (No leakage / No shorts)
- Cathode 1 / Heater Insulation: PASSED (No leakage / Perfect internal insulation)
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 67.2 on a standard scale of 150 with a multiplier of 3:
(67.2 x 3) / 150 = 1.34 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 an ECC83):
(1.34 / 1.60) x 100 = 84.0% of factory specification.
Worldwide shipping with bulletproof packaging. Tracking number provided immediately.