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SYLVANIA

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

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

€359,80 EUR
€359,80 EUR
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6SN7GTA NOS SYLVANIA – Short Base Chrome Top – Matched Quad – Same Data Codes – Made in USA 1955

AMPLITREX Tested – VERY STRONG – Green Dot & Gray Dot – Low Noise & Microphonics

Test Results:

Tubes tested on an Amplitrex AT-1000 Tube Tester:

  • Test Conditions: Va = 250V, Vg = -8V
  • Average 100% Gm = 2600 ; Ia = 9.0 mA
  • Test Result: VERY STRONG

Tube #15

  • Section 1: Gm = 2600 ; Ia = 8.2 mA
  • Section 2: Gm = 2600 ; Ia = 8.0 mA

Tube #22

  • Section 1: Gm = 2500 ; Ia = 8.0 mA
  • Section 2: Gm = 2700 ; Ia = 8.4 mA

Tube #5

  • Section 1: Gm = 2600 ; Ia = 8.4 mA
  • Section 2: Gm = 2600 ; Ia = 8.2 mA

Tube #39

  • Section 1: Gm = 2620 ; Ia = 8.6 mA
  • Section 2: Gm = 2600 ; Ia = 7.8 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-aligned, 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 quad of 6SN7GTA Sylvania, produced in the United States in 1955 and carefully selected as a Matched Quad. All four specimens share the identical manufacturing code 288 / 513, traceable to the 13th week of 1955, and feature the characteristic Short Base Chrome Top construction. A particularly desirable set for those seeking the authenticity and build quality of 1950s American Sylvania production.

The measurements performed with an Amplitrex AT-1000 highlight an electrical matching of remarkable precision. The average transconductances of the four tubes are between 2600 and 2610 µmhos, virtually coinciding with the nominal reference of 2600. Even more interesting is the uniformity of the average anode currents, concentrated in the range of 8.1–8.3 mA, compared to the reference of 9.0 mA. The individual sections feature transconductances between 2500 and 2700 µmhos and anode currents between 7.8 and 8.6 mA. An overall picture that confirms a very well-matched Quad, with small differences and particularly consistent electrical characteristics.

All four tubes passed 48 hours of burn-in and stability testing, maintaining a very strong and constant emission, without fluctuations, short circuits, or gas. Specific tests also confirmed very low noise and microphonic levels, with special Green Dot and Gray Dot classification. A selection that takes on particular value in sensitive audio stages, where silence and stability are important requirements.

The 6SN7GTA Sylvania tubes find application in hi-fi preamplifiers, headphone amplifiers, driver stages, and compatible phase inverter circuits. The uniformity of this quad makes it particularly interesting for equipment requiring multiple tubes with homogeneous electrical characteristics. 1950s Sylvania production is also traditionally appreciated by audiophiles for a musical presentation that is natural, open, and well-articulated, with a pleasant combination of definition and expressive richness.

The opportunity to bring together four authentic NOS Sylvania tubes from the same production week in March 1955, with perfectly preserved original markings, excellent cosmetic condition, and such close electrical values, gives this quad particular interest. A carefully matched vintage set that combines historical authenticity, electrical uniformity, and verified reliability, intended for enthusiasts who wish to equip their audio system with original American tubes of documented quality.

Condition

  • Condition: NOS - New Old Stock - Tested and working - Supplied in our custom box for optimal protection.
  • Functionality: Perfectly operational
  • Cosmetic condition: Excellent – Markings perfectly preserved, minimal signs of age. See photos for details.
  • Special selection: Green Dot and Gray Dot, with low noise and microphonics verified using an Amplitrex AT-1000.
  • Manufacturing code: Sylvania Electric Products Inc., USA – original marking on the base 288 / 513. 288 Sylvania Internal code. 513 - 13th week of 1955 (March 1955).

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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