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SYLVANIA

12AX7 / ECC83 SYLVANIA Long Gray plates Square Getter Tested Tube Made in USA

12AX7 / ECC83 SYLVANIA Long Gray plates Square Getter Tested Tube Made in USA

₩91,000 KRW
₩91,000 KRW
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12AX7 / ECC83 Baldwin by SYLVANIA Long Gray plates Square Getter Tested Tube
Made in USA

AMPLITREX Tested – STRONG – Vintage American Sylvania Production

Test Results:

Tube tested on AMPLITREX AT-1000 Tube Tester:

  • Test Conditions: Va = 250V ; Vg = -2V
  • 100% Average: Gm = 1600 ; Ia = 1.2 mA
  • Test Result: STRONG

Tube :

  • Section 1: Gm = 1400 ; Ia = 0.9 mA
  • Section 2: Gm = 1500 ; Ia = 0.9 mA
Additional tests performed:
  • Burn-in / Stability Test: 48h – OK
  • Microphonics: Low. Tested and compliant for use in hi-fi equipment and guitar amplifiers, even in the most sensitive audio stages.
  • Balance: Very good. The sections are consistent and well-matched, making the tube suitable even for use as a phase inverter in hi-fi and instrumental applications.
  • Emission Quality: Strong – Strong and steady emission, suitable for any application.
  • Shorts and GAS: None.

Description

A unique and rare 12AX7 / ECC83 Baldwin produced by Sylvania, characterized by its sought-after Long Gray Plates and Square Getter construction. This configuration is typical of early American production and decidedly less common than the later versions with short plates and halo getters; it is interesting both for audio use and for vintage tube collectors.

The code 312 952 identifies Sylvania Electric Products Inc., Emporium, Pennsylvania, and places the manufacture in the 52nd week of 1959. The Baldwin branding indicates the OEM destination for the well-known American manufacturer's equipment, while the internal features clearly point to original Sylvania production.

After a 48-hour burn-in cycle, the tube was tested with an Amplitrex AT-1000, recording Gm 1400 with Ia 0.9 mA for the first section and Gm 1500 with Ia 0.9 mA for the second. The emission is strong, steady, and stable, with transconductance values close to the nominal reference.

The very good balance is one of the specimen's main strengths. The plate currents are perfectly matched and the difference in Gm is minimal, making the tube suitable even as a phase inverter, as well as a driver or in stages where consistency and good symmetry between sections are required.

The low microphonics selection allows for its use even in the most sensitive audio stages of hi-fi equipment and guitar amplifiers. From a sonic perspective, this Sylvania production is appreciated for an open, dynamic, and natural presentation, with good definition, controlled response, and a convincing balance across the entire audio range.

A vintage Made in USA 12AX7 / ECC83 that is particularly interesting for its origin and construction: 1959 Sylvania production, Baldwin branding, Long Gray Plates, Square Getter, and well-matched sections. Tested, fully functional, and free of shorts or gas, it is ready to return to service in compatible equipment.

Condition:

  • Condition: Vintage Tubes - Tested and fully functional. Supplied in our custom box for optimal protection.
  • Functionality: Fully operational.
  • Cosmetic Condition: Good – Markings are clearly legible with slight signs of aging. See photos for details.
  • Manufacturing Code: 312 952 → 312 indicates the manufacturer, Sylvania Electric Products Inc., Emporium, Pa. - 952 → 9 (of three digits) → 1959 - 52 → 52nd week of the year

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Terms of Sale & Safety

Sales Terms & Product Safety

Each vacuum tube is carefully selected, tested, and verified in our laboratory before shipment. Where stated in the listing, test results, matching data, and declared characteristics refer to measurements performed using the specified test equipment and operating conditions.

Sound descriptions are provided for guidance only and reflect the characteristics generally associated with that particular tube type. Personal sound preferences, tube rolling, or perceived differences between audio systems do not constitute a product defect.

Before installation, please verify the tube’s electrical and mechanical compatibility with your equipment and follow the manufacturer’s instructions.

New production and NOS tubes are shipped with a tamper-evident security seal and internal technical documentation to ensure traceability of the product’s condition at the time of shipment.

Product Safety (GPSR)

Vacuum tubes are electronic components intended exclusively for use in compatible equipment and must be installed in accordance with the equipment manufacturer’s instructions.

Due to their historical or vintage nature, certain technical specifications may be based on original datasheets or equivalent technical documentation when documentation from the specific manufacturer is unavailable.

Use only with suitable equipment. Keep out of reach of children.

Shipping & Returns

Shipping & Returns

We ship worldwide using carefully selected express carriers and protective packaging specifically designed for vacuum tubes.

If you change your mind, you may exercise your right of withdrawal within 14 days of delivery, where applicable under the relevant consumer protection laws. The product must be returned complete with its original packaging and accessories, in the same commercial condition in which it was received. Return shipping costs are the responsibility of the customer.

Every returned item undergoes a technical inspection. Installation, use, tube rolling, or any other handling may reduce the product’s commercial value and may affect the refund amount, in accordance with applicable law.

If you believe the product has a lack of conformity, our laboratory will carry out the necessary inspections and apply the remedies provided by the applicable consumer protection legislation.

For further details, Customers are invited to consult the “Terms and Conditions” and “Refund Policy” sections of our website, or to contact us before placing an order.

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