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RCA

5963 ( 12AU7 ) RCA Matched Quad Long Black Plates Foil Getter AMPLITREX Tested

5963 ( 12AU7 ) RCA Matched Quad Long Black Plates Foil Getter AMPLITREX Tested

€164,90 EUR
€164,90 EUR
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5963 (12AU7 / ECC82) RCA – Matched Quad – Black Plates – Foil Getter

AMPLITREX Tested – Made in USA – 1956

Description:

This matched quartet of 5963 (12AU7 / ECC82) RCAs, Made in USA 1956 , belongs to one of the most fascinating and musical productions of RCA of the 1950s. The construction with black plates and foil getters is typical of the superior quality series, created for professional applications and today sought after for their warm, authoritative and incredibly refined sonic character.

The valves are AMPLITREX Tested and carefully selected as Matched Quad : the overall behavior is coherent, stable and silent, with a performance that immediately conveys the feeling of a “special”, uncommon component.

  • Bass: Compact, controlled, and well-articulated. The low end is tidy and precise, with a dry feel that promotes clarity and rhythm.
  • Mids: Balanced and natural. Vocals are credible and well-focused, with a harmonic texture that's typical of RCA: solid, musical, and free from excessive coloration.
  • Highs: Clean and well-integrated. The highs are smooth and controlled, without harshness, with consistent detail that never becomes fatiguing.
  • Dynamics: Smooth and fluid. The response is prompt but composed, with predictable and stable behavior, ideal for line stages and drivers.
  • Soundstage: Stable and well-organized soundstage. Good separation of sound planes and correct imaging, with an orderly and realistic presentation.

🎧 Use in Hi-Fi Stereo Amplifiers

Ideal for:

  • preamplifiers and line stages in non-critical positions
  • drivers and buffers
  • Vintage and modern hi-fi amplifiers compatible with 12AU7 / 5963

Particularly suitable for non-critical or moderate gain positions, where operational stability, low overall noise and timbral coherence are required.

🎸 Use in Musical Instrument Amplifiers

Suitable for:

  • Guitar and bass amplifiers in driver, phase inverter or V2/V3 positions
  • applications where operational stability, good control and low background noise are required
  • use in studios or in professional settings where low overall noise is an important requirement

It offers reliable, controlled operation, with low noise and predictable response.
It is recommended to avoid using them in the most sensitive or very high-gain positions; however, they are perfectly suited to less critical stages, where they can offer reliable and consistent operation.

🎯 Note for audiophiles and technicians

A solid and coherent quartet, designed for those seeking reliability, musicality and the classic RCA character of the 50s, without compromising on operational stability.

Test Results:

Valve tested on AMPLITREX AT-1000 Tube Tester:

  • Test Conditions: Va = 250V ; Vg = -8.5V
  • Average 100%: Gm = 2200 ; Ia = 10.5 mA
  • Test Result: VERY STRONG
Valve #23:
  • Section 1: Gm = 2100 ; Ia = 9.6 mA
  • Section 2: Gm = 1900 ; Ia = 8.2 mA
Valve #27:
  • Section 1: Gm = 2100 ; Ia = 9.6 mA
  • Section 2: Gm = 1900 ; Ia = 9.0 mA
Valve #31:
  • Section 1: Gm = 2160 ; Ia = 10.4 mA
  • Section 2: Gm = 1860 ; Ia = 9.0 mA
Valve #34:
  • Section 1: Gm = 2000 ; Ia = 9.4 mA
  • Section 2: Gm = 2050 ; Ia = 10.2 mA
Additional Tests Performed:
  • Microphonics: Standard. Tested and approved for use in hi-fi and guitar amplifiers. Recommended for use in V2, V3, V4, as a driver, or in less critical stages. Not recommended in V1 or in very high-gain positions that are particularly sensitive to microphonics.
  • Balance: The sections present a coherent overall balance, fully compatible with use in hi-fi and musical amplifiers, in all applications where absolute symmetry between the sections is not required.
  • Output Quality: Excellent – Very strong and stable output, no fluctuations.
  • Short circuits and GAS: Absent.

Conditions:

  • Condition: Vintage - Tested and working - Comes in our custom box for optimal protection.
  • Functionality: Fully functional.
  • Cosmetic condition: Good – Lettering partially eroded, but still legible. Valve body in good condition. See photos for details.

Manufacturing Code:

  • 56-30 → RMA/EIA Open Date Code → manufactured week 30 of 1956
    56-52 → RMA/EIA Open Date Code → manufactured week 52 of 1956

Find out why our valves 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.

Vacuum Tubes Treasures
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📧 info@vacuumtubestreasures.com

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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.

  • ATTENTION PLEASE

    We wish to inform you that any attempts to manipulate shipping destination information in order to obtain lower shipping rates may be considered fraudulent acts. Please provide accurate information and contact us if you have any concerns. We reserve the right to review and, if necessary, cancel orders that we deem to be in violation of our conditions. Thank you for your understanding and cooperation.