Vintage Mazda 12AX7 / ECC83 Tube | Tested Balanced VII-7 Batch | Kalibr L3-3

빈티지 마쓰다 12AX7 / ECC83 튜브 | 테스트된 밸런스 VII-7 배치 | 칼리브르 L3-3

상품번호	198404931049
상태	Used
거래유형	즉시구매
출고국	미국 (US)

이베이 판매가

$55

약 81,070원

구매대행 예상 비용은 로그인 후 확인하실 수 있습니다.

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.

Why buy from us? Validated Quality (no guesswork, just documented performance) | Safe Shipping (double-boxed with anti-vibration materials) | Expert Service (specializing in high-end vintage electronics).

For sale is a premium, vintage Mazda 12AX7 / ECC83 dual triode tube (Internal Reference: TG3M74). This authentic French production features the classic silver-white brand label and the distinct VII-7 historical batch code stamped directly on the glass. Mazda tubes from this era are highly celebrated by audiophiles and guitar players for their exceptionally low noise floor, crisp high-end detail, and highly dynamic, open soundstage.

Vintage Authenticity & Performance

While this unit has been previously used and comes without its original cardboard packaging, it has been meticulously measured and audited on our professional, lab-grade Kalibr L3-3 tube tester.

The structural integrity is excellent, and the electrical performance shows a beautifully balanced transconductance (S) tracking tight and parallel across both internal triode sections. This balanced performance is crucial for ensuring identical channel gain in high-end audio preamplifiers.

Key Features

Brand / Label: Mazda (Classic Silver Stamp with VII-7 Batch Code)
Type: 12AX7 / ECC83
Design: Short Dark Gray Plates / Halo Getter / Ruggedized Double Mica Support
Condition: Tested Strong / Vintage Used (Beautifully balanced amplification sections)
Packaging: Shipped in a secure, generic white protective box (No original box)
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)

Triode Section 1:
• Anode Current (Ia): 0.96 mA (79.7% of factory spec)
• Transconductance (S): 1.51 mA/V (94.3% of factory spec)

Triode Section 2:
• Anode Current (Ia): 0.95 mA (79.5% of factory spec)
• Transconductance (S): 1.40 mA/V (87.4% of factory spec)

🌟 Seller Note on Performance: With an anode current (Ia) tracking at an almost identical 0.96 mA / 0.95 mA, and a mutual conductance (S) standing strong at 1.51 mA/V / 1.40 mA/V (up to 94.3% of factory baseline), this tube offers outstanding electrical balance. It is fully optimized and ready to bring its distinct vintage French musicality to your premium Hi-Fi phono stages, studio gear, or classic guitar amplifiers.

Structural & Insulation Tests Passed

This specimen has been individually audited and successfully met all 5 laboratory insulation criteria:

Insulation test between Cathode (k) and Heater (H) 1st section: PASSED (No leakage)
Insulation test between Cathode (k) and Grid 1 (g1) 1st section: PASSED (No shorts)
Insulation test between Grid section 1 (g1) and Grid section 2 (g2): PASSED (No inter-section leakage)
Insulation test between Cathode (k) and Heater (H) 2nd section: PASSED (No leakage)
Insulation test between Cathode (k) and Grid 2 (g2) 2nd section: 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 75.4 on a standard scale of 150 with a multiplier of 3:
(75.4 x 3) / 150 = 1.51 mA/V
Percentage vs. Factory Specs:
We then benchmark this result against the factory nominal value for a new tube (e.g., 1.6 mA/V for an ECC83):
(1.51 / 1.6) x 100 = 94.3% of factory specification.

Worldwide shipping with bulletproof packaging. Tracking number provided immediately.

구분	220	225	230	235	240	245	250	255	260	265	270	275	280
한국	220	225	230	235	240	245	250	255	260	265	270	275	280
미국	5	5.5	6	6.5	7	7.5	8	8.5	9	9.5	10	10.5	11
영국	2	2.5	3	3.5	4	4.5	5	5.5	6	6.5	7	7.5	8

구분	240	245	250	255	260	265	270	275	280	285	290	295	300
한국	240	245	250	255	260	265	270	275	280	285	290	295	300
미국	6.5	7	7.5	8	8.5	9	9.5	10	10.5	11	11.5	12	13
영국	5.5	6	6.5	7	7.5	8	8.5	9	9.5	10	10.5	11	12

구분	사이즈
발길이(mm)	70	83	89	92	95	102	105
미국	0	0.5	1	1.5	2	2.5	3

구분	사이즈
발길이(mm)	108	114	117	121	127	130	133	140	143	146	152	156	159
미국	10.5	11	11.5	12	12.5	13	13.5	1	1.5	2	2.5	3

구분	사이즈
발길이(mm)	168	171	178	181	184	191	194	197	203	206	210	216
미국	6.5	7	7.5	8	8.5	9	9.5	10	10.5	11	11.5	12

구분	XS	S	M	L	XXL
한국/일본 1	90이하	90	95	100	100이상
한국 2	44	55	66	77	88
미국 (문자)	XS	S	M	L	XXL
미국 (숫자)	2	4-6	8-10	12-14	14-16
이태리	36	38~40	42~44	46~48	50~52

부위	XS	S	M	L	XXL
가슴둘레 (cm)	81~84	86~89	91~97	99~104	109~114
가슴둘레 (inch)	32~33	34~35	36~37	38~39	40+
팔길이 (cm)	75~76	77~79	80~81	83~84	85~86
허리둘레 (cm)	61~64	66~69	71~76	79~84	89~94
허리둘레 (inch)	24~25	26~27	28~30	31~33	35~37
힙둘레 (cm)	88~90	93~95	98~102	105~109	114~119
힙둘레 (inch)	34	35~36	37~38	39~41	42~45

구분	0-1	3-5	7-9	10-13
미국 (숫자)	0-1	3-5	7-9	10-13
한국 2	44	55	66	77
가슴둘레 (inch)	31~32	33~34	35~36	37~38
허리둘레 (inch)	23~24	25~26	27~28	29~30
힙둘레 (inch)	34~35	36~37	38~39	40~41

밑가슴	가슴둘레	한국	미국	허용범위
65	70~73	65A	30AA	63~68cm
	74~76	65B	30A
	77~79	65C	30B
	79~81	65D	30C
	81~83	65DD	30D
70	79~81	70A	32AA	68~73cm
	82~84	70B	32A
	84~86	70C	32B
	86~88	70D	32C
	89~91	70DD	32D
75	83~86	75A	34AA	73~78cm
	87~89	75B	34A
	89~91	75C	34B
	91~93	75D	34C
	93~95	75DD	34D
80	89~91	80A	36AA	78~83cm
	92~94	80B	36A
	94~96	80C	36B
	96~98	80D	36C
	98~100	80DD	36D
85	94~96	85A	38AA	83~88cm
	97~99	85B	38A
	99~101	85C	38B
	101~103	85D	38C
	103~105	85DD	38D
90	99~101	90A	40AA	88~93cm
	102~104	90B	40A
	104~106	90C	40B
	106~108	90D	40C
	108~110	90DD	40D

사이즈	한국	미국	Bust	Waist	Hip
XXS	85	0	31.5	23	33.5
XS	90	2	32.5	24	34.5
XS	90	4	33.5	25	35.5
S	95	6	34.5	26	36.5
S	95	8	35.5	27	37.5
M	95	10	36.5	28	38.5
M	100	12	38	29.5	40
L	105	14	39.5	31	41.5
L	105	16	41	32.5	43
XL	110	18	43	34.5	45
XL	110	20	45	46.5	47

구분	5	6	7	8	9	10	11	12	13	14	15
한국	5	6	7	8	9	10	11	12	13	14	15
미국	3	3.5	4	4.5	5	5.5	6	6.5	6.5	7	7
독일	45	46	47	48	49	50	51	52	53	54	55
mm			46.5	46.5	46.5	50.3	51.5	52.8	52.8	54	54

구분	XS	S	M	L	XL	XXL
미국	XS	S	M	L	XL	XXL
여성 허리 (inch)	24	25~26	27~28	29~31	32~34	36~38

구분	16	17	18	19	20	21	22	23	24	25	26
한국	16	17	18	19	20	21	22	23	24	25	26
미국	7.5	8	8.5	9	9.5	10	10.5	10.5	11	11.5	12
독일	56	57	58	59	60	61	62	63	64	65	66
mm	55.3	56.6	57.8	59.1	60.3	61.6	62.8	62.8	64.1	65.3	66.6