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RAYTHEON

12AU7 / ECC82 RAYTHEON Matched Pair Long Black Plate Square Getter Tested Tubes USA '57

12AU7 / ECC82 RAYTHEON Matched Pair Long Black Plate Square Getter Tested Tubes USA '57

875,00 NOK
875,00 NOK
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12AU7 / ECC82 RAYTHEON Matched Pair Long Black Plate Square Getter Tested Tubes USA '57

Low Noise & Microphonics – STRONG - Vintage American Raytheon Production

Test Results:

Tube tested on an AMPLITREX AT-1000 Tube Tester:

  • Test Conditions: Va = 250V ; Vg = -8.5V
  • 100% Average: Gm = 2200 ; Ia = 10.5 mA
  • Test Result: STRONG

Tube #2:

  • Section 1: Gm = 1700 ; Ia = 7.8 mA
  • Section 2: Gm = 1800 ; Ia = 9.0 mA

Tube #3:

  • Section 1: Gm = 1800 ; Ia = 8.6 mA
  • Section 2: Gm = 1800 ; Ia = 9.2 mA
Additional Tests Performed:
  • Burn-in / Stability Test: 48h – OK
  • Microphonics: Very Low. Tested and compliant for use in hi-fi equipment and guitar amplifiers, even in the most sensitive audio stages.
  • Noise: Low and well-controlled. Quiet operation in hi-fi environments and in musical amplifiers in the intended positions.
  • Balance: Good. The sections show a consistent balance, fully compatible with use in hi-fi and musical amplifiers, in all applications where absolute symmetry between sections is not required.
  • Emission Quality: Strong – Strong and steady emission, suitable for any application.
  • Short Circuits and GAS: Absent.

Description:

A prized pair of American-made 12AU7 / ECC82 Raytheon tubes, manufactured in the 23rd week of 1957 and featuring the sought-after Long Black Plates and Square Getter construction. The code 280 57-23 identifies the Raytheon Manufacturing Company and precisely documents both the manufacturer and the production period of the two units.

The tubes form a particularly consistent Amplitrex Matched pair. Tube #2 shows an average transconductance of 1750 µmhos, while Tube #3 reaches 1800 µmhos, with a difference of less than 3%. The average plate currents are also well-matched, at 8.4 and 8.9 mA respectively, confirming good operational consistency between the two units.

The internal balance is overall very convincing. Tube #2 measures 1700/1800 µmhos and 7.8/9.0 mA, while Tube #3 reaches 1800/1800 µmhos and 8.6/9.2 mA. The latter shows perfectly matching transconductance between the two sections; the former maintains a good balance, despite showing a more evident difference in plate current. The pair is therefore suitable for standard hi-fi and instrumental applications, while for circuits requiring absolute symmetry, a more rigorous selection is preferable.

The 48-hour burn-in confirmed stable and steady operation, with no fluctuations, short circuits, or gas presence. The very low microphonics and well-controlled noise represent a significant strength, making these tubes suitable for preamplifiers, buffers, line stages, drivers, and particularly sensitive audio positions.

In terms of sound, Raytheon Long Black Plates are prized for a dynamic, natural, and full-bodied reproduction, with a rich and well-articulated midrange, solid low frequencies, and a defined high end that is never harsh. In hi-fi systems, they promote musicality, depth, and a stable soundstage; in musical instrument amplifiers, they ensure a responsive, controlled, and authoritative character.

A proposal of considerable interest for those looking for a matching Raytheon American pair from the same lot, with Long Black Plates, Square Getter, accurately matched transconductance, very low microphonics, and excellent aesthetic condition: two authentic 1957 12AU7/ECC82s, individually tested and ready for use.

Conditions:

  • Condition: Vintage Tubes - Tested and perfectly functional. Supplied in our custom box for optimal protection.
  • Aesthetic condition: Excellent – Lettering well-preserved, minimal signs of age. See photos for details.
  • Manufacturing Code: 280 57-23 → 280 indicates the manufacturer, Raytheon Mfg. Company, Newton 58, Mass. - 57-23 → RMA/EIA Open Date Code → manufactured in the 23rd week of 1957

Discover why our tubes are different →

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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  • ATTENTION PLEASE

    Please understand that the writing on the glass of vintage valves has become very delicate over the years and comes off easily. You must handle them with extreme care to avoid this. Wear and damage to the writing on the valves reduces their market value and causes damage. Please exercise extreme caution.

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