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SYLVANIA

6SN7GTA NOS SYLVANIA Chrome Top Matched Sextet - Same Production Code - Low Noise & Microphonics - AMPLITREX Tested

6SN7GTA NOS SYLVANIA Chrome Top Matched Sextet - Same Production Code - Low Noise & Microphonics - AMPLITREX Tested

2.838,00 RON
2.838,00 RON
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6SN7GTA NOS SYLVANIA – Short Base Chrome Top – Black Plates – Matched Sextet – Made in USA 1955

AMPLITREX Tested – VERY STRONG – Matched Sextet – Low Noise & Microphonics

Test Results:

Tested on Amplitrex AT-1000 Tube Tester:

  • Test Conditions: Va = 250V; Vg = -8V
  • 100% Average: Gm = 2600; Ia = 9.0 mA
  • Test Result: VERY STRONG
  • Sextet Range on Tube Averages: Gm = 2600–2600; Ia = 7.6–7.8 mA
  • Matched Score: 2.60 – Excellent Match

Tube #6

  • Section 1: Gm = 2600; Ia = 7.6 mA
  • Section 2: Gm = 2600; Ia = 7.6 mA

Tube #37

  • Section 1: Gm = 2600; Ia = 7.8 mA
  • Section 2: Gm = 2600; Ia = 7.4 mA

Tube #35

  • Section 1: Gm = 2600; Ia = 7.6 mA
  • Section 2: Gm = 2600; Ia = 7.8 mA

Tube #4

  • Section 1: Gm = 2500; Ia = 7.4 mA
  • Section 2: Gm = 2700; Ia = 8.0 mA

Tube #7

  • Section 1: Gm = 2600; Ia = 7.6 mA
  • Section 2: Gm = 2600; Ia = 8.0 mA

Tube #8

  • Section 1: Gm = 2600; Ia = 7.6 mA
  • Section 2: Gm = 2600; Ia = 8.0 mA

Additional Tests:

  • Burn-in / Stability Test: 48h – OK
  • Microphonics and noise: Very Low. Tested and suitable for use in hi-fi equipment and guitar amplifiers, including the most sensitive audio stages.
  • Balance: Very good. The sections are consistent and well-matched, making the tube suitable for use as a phase inverter in hi-fi and instrument applications.
  • Emission: Excellent – Very strong and stable emission, without fluctuations.
  • Short Circuits / Gas: none

Description

Exceptional NOS 6SN7GTA Sylvania sextet, produced in the United States in 1955 and carefully selected as a Matched Sextet. All six tubes share the identical manufacturing code 288 / 513, dating back to the 13th week of 1955, and feature the characteristic Short Base Chrome Top with Black Plates construction. A particularly interesting set due to its construction uniformity and its origin from the same 1950s Sylvania American production run.

The measurements performed with the Amplitrex AT-1000 reveal an exceptionally precise match. All six tubes have an identical average transconductance of 2600 µmhos, corresponding to the nominal reference, while the average anode currents are concentrated in the extremely narrow range of 7.6–7.8 mA. Considering the individual sections, the transconductance varies from 2500 to 2700 µmhos and the anode current from 7.4 to 8.0 mA. The Matched Score of 2.60 confirms the excellent overall uniformity, a particularly significant feature for a group of six vintage tubes.

Each tube passed 48 hours of burn-in and stability testing, demonstrating very strong and consistent emission, without fluctuations, short circuits, or gas. The tests also confirmed very low noise and microphonics levels, with special Green Dot and Gray Dot selection verified using the Amplitrex AT-1000.

  • Manufacturing code: Sylvania Electric Products Inc., USA – original marking on the base 288 / 513. 288 is the Sylvania internal code. 513 - 13th week of 1955 (March 1955).

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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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    • 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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