1 10

SYLVANIA

6SL7GT SYLVANIA 3-Hole Black Plates Tall Boys AMPLITREX Tested Pair Made in USA '50s

6SL7GT SYLVANIA 3-Hole Black Plates Tall Boys AMPLITREX Tested Pair Made in USA '50s

€99,90 EUR
€99,90 EUR
Sale Sold out
Taxes included. Shipping calculated at checkout.

6SL7GT SYLVANIA 3-Hole Black Plates Tall Boys AMPLITREX Tested Pair Made in USA '50s

General Description

This pair of 6SL7GT SYLVANIA “Tall Boys”, produced in the United States in the 1950s, represents one of the most fascinating and recognizable configurations of the great American production.

The tubes stand out for their iconic and highly appreciated construction:

  • 3-Hole Black Plates
  • Tall Boys structure (tall bottle, typical of early productions)
  • Different Date Codes but same year of production
  • entirely Made in USA construction

This is a selected and tested used pair, not a random combination, but a conscious choice based on real performance and sonic consistency.

Although not a matched pair, the tubes exhibit a consistent internal balance, fully compatible with hi-fi and musical use in all applications where strict symmetry is not required.

Tested with Amplitrex AT-1000, they achieved:

  • Result: STRONG
  • Internal VTT Classification: STRONG
  • Low Noise & Microphonics

A proposition that combines historical charm, build quality, and authentic musical reproduction, superior to the average of generic used pairs.

Sonic Characteristics

Bass

Soft and well-articulated, with a natural presence that supports the soundstage without weighing it down.

Mids

Absolute strong point: rich, textural, and three-dimensional. Vocals emerge with great naturalness and engagement.

Highs

Sweet and well-extended, never aggressive. They offer air and detail while maintaining a consistently musical rendition.

Dynamics

Fluid and progressive, with a natural response that prioritizes musicality and coherence.

Soundstage

Wide and airy, with a well-developed stage and credible instrument separation.

🎧 Use in Hi-Fi Stereo Amplifiers

Ideal for:

  • tube preamplifiers
  • input stages
  • circuits where musicality and naturalness are required

Thanks to low noise and good internal coherence, they easily integrate into most hi-fi configurations, offering a natural and engaging sound.

🎸 Use in Musical Amplifiers

Excellent choice for:

  • vintage instrument amplifiers
  • tube preamplifiers

They offer:

  • great expressiveness in the mids
  • musical dynamic response
  • authentically "vintage" sonic character

🎯 Note for audiophiles and technicians

  • SYLVANIA USA – 1950s
  • 3-Hole Black Plates – Tall Boys
  • Different Date Codes (same year)
  • Selected pair, not matched
  • Low Noise & Microphonics

A pair that expresses identity, coherence, and musicality, designed for those who desire an authentic American 6SL7, judiciously selected and capable of offering a credible and satisfying sound experience.

Test Results:

Tubes tested on Amplitrex AT-1000 Tube tester:

  • Test Conditions: Va = 250V, Vg = -2V
  • Average 100%: Gm = 1600 ; Ia = 2.3 mA
  • Test Result: STRONG

Tube 1:

  • Section 1: Gm = 1500 ; Ia = 2.3 mA
  • Section 2: Gm = 1400 ; Ia = 2.1 mA

Tube 2:

  • Section 1: Gm = 1200 ; Ia = 2.0 mA
  • Section 2: Gm = 1300 ; Ia = 2.2 mA
Additional Tests Performed:
  • Microphonics: Low. Tested and suitable for hi-fi use, including in phono stages and guitar amplifiers. Also suitable for V1.
  • Balance: The sections exhibit a consistent balance, fully compatible with use in hi-fi and musical amplifiers, in all applications where absolute symmetry is not required.
  • Emission Quality: Strong – Strong and regular emission, suitable for any application.
  • Shorts and GAS: None.

Conditions:

  • Conditions: Vintage Tubes - Tested and fully functional - Supplied in Original Box.
  • Functionality: Perfectly operational.
  • Aesthetic conditions: Excellent – Markings are excellently preserved, minimal signs of age. See photos for details.

Manufacturing Code:

  • 018 → Sylvania Electric Products Inc., Emporium, Pa. - 018 → 0 ( three digits ) → 1950 - 18 → 18th week of the year
  • 022 → Sylvania Electric Products Inc., Emporium, Pa. - 018 → 0 ( three digits ) → 1950 - 22 → 22nd week of the year

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.

Vacuum Tubes Treasures
www.vtt.store | www.vacuumtubestreasures.com
📧 info@vacuumtubestreasures.com

View full details

  • 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.