1 14

RCA

12AX7 / ECC83 RCA Matched Pair Long Black Plates Square Tilt getter Made in USA '58

12AX7 / ECC83 RCA Matched Pair Long Black Plates Square Tilt getter Made in USA '58

¥1,608.00 CNY
¥1,608.00 CNY
Sale Sold out
Shipping calculated at checkout.
🖨️ Print as PDF

12AX7 / ECC83 RCA Matched Pair Long Black Plates Square Tilt Getter Made in USA 1958

AMPLITREX Tested – Low Noise & Microphonics – Vintage American Black Plates

Description:

This matched pair of 12AX7 / ECC83 RCA, manufactured in the USA in 1958, represents one of the most fascinating and sought-after configurations from the golden age of American small signal tubes.

The construction with Long Black Plates and rare Square Tilt Getter identifies an RCA production from the late 1950s particularly appreciated for its musicality, harmonic richness, and strong sonic personality. This type is historically much loved by both audiophiles and enthusiasts of vintage musical instrument amplifiers.

The tubes are used, meticulously tested, and selected in our laboratory using the AMPLITREX AT-1000 Tube Tester, with particular attention to low noise, contained microphonics, and operational consistency of the pair.

This pair is offered as a selected Matched Pair, with overall consistent electrical behavior, good operational uniformity, and very interesting sonic characteristics in hi-fi and musical applications.

From an aesthetic point of view, the pair is in particularly beautiful and very clean condition for its age: the RCA silkscreen is still well preserved, the internal structures are visually very appealing, and the ensemble maintains that typical aesthetic impact of authentic 1950s American black plates.

The value of this pair is strongly linked to the combination of:

  • original USA RCA brand;
  • vintage 1958 production;
  • Long Black Plates structure;
  • Square Tilt Getter;
  • matched pair;
  • low noise;
  • low microphonics;
  • excellent aesthetic presence.

Sonic Characteristics

RCA long black plates from the 1950s are famous for a broad, musical, and harmonically rich sound presentation, with a deeply American character: full-bodied, natural, and engaging.

This pair clearly retains that typical vintage RCA sonic imprint, capable of combining musicality, fluidity, and an extremely pleasant harmonic texture.

Bass

The bass range is full, round, and natural, with a good sense of body and presence. The bass maintains musicality and control without being artificially emphasized.

Mids

The mids are probably the most seductive aspect of this RCA production. Vocals are rich, dense, and believable, while acoustic instruments and harmonics retain a rich and very musical texture.

That typical vintage American softness is present, making these RCAs particularly satisfying for long listening sessions.

Highs

The high range is fluid, refined, and never aggressive. Detail remains present but naturally integrated, contributing to a relaxed and elegant listening experience.

Dynamics

The dynamic response appears musical and progressive, with a good ability to follow harmonic and dynamic variations without rigidity or harshness.

Soundstage

The soundstage is stable, airy, and well-organized. The image maintains good depth and correct instrument separation, with a very credible and engaging presentation.

🎧 Use in Hi-Fi Amplifiers

These RCA ECC83 / 12AX7 are particularly suitable for:

  • hi-fi preamplifiers;
  • line stages;
  • phono stages;
  • vintage and modern integrated amplifiers;
  • compatible driver stages.

The Low Noise & Microphonics selection makes them very interesting even in sensitive applications and systems oriented towards musicality and tonal naturalness.

🎸 Use in Musical Applications

In the world of guitar amplifiers, RCA long black plates from the 1950s are considered by many enthusiasts to be among the most musical and fascinating American ECC83s ever produced.

This pair offers:

  • excellent harmonic response;
  • rich and three-dimensional mids;
  • great musicality;
  • natural dynamic behavior;
  • contained noise and low microphonics.

Characteristics that make them very interesting for use in vintage, boutique, and studio amplifiers.

🎯 Note for audiophiles and technicians

This pair represents a vintage American selection of strong historical and aesthetic appeal, designed for those who desire authentic 1950s USA RCA black plates with:

  • Long Black Plates construction;
  • Square Tilt Getter;
  • matched pair;
  • high quietness;
  • low microphonics;
  • typical vintage RCA musicality.

Despite being used vintage tubes, their overall value remains very high due to the build quality, the rarity of the internal configuration, the aesthetic beauty, and the sonic character typical of the best American productions of the era.

A 1958 RCA black plates pair with strong vintage American charm, selected for musicality, quietness, and sonic authenticity, in line with the Vacuum Tubes Treasures philosophy.

Test Results

Tested on AMPLITREX AT-1000 Tube Tester

Voltage Test: Va = 250V, Vg = -2V
Average 100%: Gm = 1600 ; Ia = 1.2 mA
TEST RESULT:
Gm Profile: VERY STRONG
Anode Current Ia: Strong

Tube #8:

  • Section 1: Gm = 1400 ; Ia = 0.8 mA
  • Section 2: Gm = 1400 ; Ia = 0.8 mA

Tube #10: 

  • Section 1: Gm = 1500 ; Ia = 0.8 mA
  • Section 2: Gm = 1400 ; Ia = 0.8 mA

Additional Tests performed:
  • Microphonics: Low Noise & Microphonics – Tested and suitable for use in hi-fi systems and guitar amplifiers.
  • Noise: Low and well controlled. Quiet operation in hi-fi and musical amplifiers in the intended positions.
  • Emission Quality: Strong – Strong and regular emission, suitable for any application.
  • Shorts and GAS: Absent.

Conditions:

  • Condition: Vintage Tubes - Tested and fully functional. Supplied in our custom box for optimal protection. 
  • Functionality: Perfectly operational.
  • Aesthetic conditions: Excellent – Markings excellently preserved, minimal signs of age. See photos for details.

Manufacturing Code:

  • 58-09 → RMA/EIA Open Date Code → manufactured in the 9th week of 1958 → Radio Corporation of America, Camden, N. J.

Discover why our tubes are different →

Condizioni di vendita e sicurezza

Anti-Tamper Security Seal Policy:
Each product is sealed to guarantee quality and integrity.
The right of withdrawal is subject to the seal remaining intact, as provided for by the Consumer Code.

Eco-Friendly Packaging:
The tube will be shipped with protective packaging to ensure safety during transport.
We use recycled and recyclable paper for packaging, along with brown ECO-KRAFT adhesive tape, eco-friendly and solvent-free.

Important Notes:
This tube, manufactured according to the standards of its era, is designed to operate in equipment compatible with vintage tubes.
It is recommended to follow standard safety guidelines to avoid malfunctions or damage.

Safety Assurance:
Although not tested according to modern GPSR regulations, this tube was designed to operate safely under the conditions for which it was manufactured.
We recommend using it only with equipment that supports vintage tubes, in order to avoid risks of malfunction or damage.
Technical data note:
In some cases, the technical data provided may be based on datasheets from other manufacturers or on equivalent historical specifications, when a specific official datasheet for the production batch of the listed item is not available.
Electrical characteristics may vary slightly depending on the production batch and manufacturing period, as is typical for thermionic components.

Safety Information:
Warning: Keep out of reach of children.
To be used under adult supervision.
Use the product only with equipment designed for vintage tubes.

Shipping & Returns

Shipping & Returns

Shipping Costs

Shipping costs vary depending on the total amount of the items in the cart and are calculated automatically during the checkout process.
All shipments are fully insured. The courier is automatically selected based on destination, weight, and shipment characteristics.

Shipping Times and Delivery

The indicated delivery times are purely indicative.
Any delays, storage issues, or operational changes made by the carrier (for example during peak periods such as holidays) are not attributable to Vacuum Tubes Treasures.

In such cases, we will nevertheless provide the Customer with all necessary support to open claims or assistance requests with the appointed courier.

International Shipping (Non-EU Countries)

For orders shipped to countries outside the European Union, any customs duties, import taxes, or additional charges are the sole responsibility of the recipient.
Vacuum Tubes Treasures has no control over these costs, which may vary from country to country. Customers are therefore advised to contact their local customs authorities prior to placing an order.

Warranty

All products sold by Vacuum Tubes Treasures are covered by the legal warranty of conformity, in accordance with Italian Legislative Decree No. 206/2005 (Consumer Code) and the Italian Civil Code (Articles 1490 et seq.), under the conditions set out below.

Warranty for Vacuum Tubes

Vacuum tubes, being components subject to wear and of vintage or specialized nature, are covered by a specific warranty of 6 (six) months from the date of delivery.
The warranty covers exclusively proven manufacturing or conformity defects that arise during proper use in accordance with technical specifications.

The warranty does not cover:

  • normal wear and tear,
  • subjective sound preferences,
  • use in incompatible equipment,
  • tampering or improper use.

Right of Withdrawal

Purchases made on the Vacuum Tubes Treasures website are governed by Italian regulations on distance contracts (Legislative Decree No. 206/2005).

Consumers have the right to withdraw from the contract within 14 (fourteen) days from the date of receipt of the goods, without providing any reason.

Conditions for Exercising the Right of Withdrawal

The right of withdrawal may be exercised only if:

  • the product has not been used,
  • the product is returned in its original condition,
  • the tamper-evident security seal is intact and not broken.

📌 Returns are not accepted for reasons related to sound preference, tube rolling, or subjective audio evaluation.
As with a music recording, a vacuum tube cannot be returned simply because its sound does not match personal taste.

Effects of Withdrawal

In the event of a valid withdrawal:

  • all payments received, including standard shipping costs, will be refunded,
  • refunds will be issued within 14 days from receipt of the returned goods,
  • the refund may be withheld until the goods have been received and inspected.

Refunds will be made using the same payment method used for the original transaction, unless otherwise agreed.

Return Shipping Costs

Return shipping costs are borne by the Customer, except in cases of:

  • verified defective products,
  • errors attributable to Vacuum Tubes Treasures.

In such cases, return shipping costs will be fully covered by us.

Damaged or Incorrect Items

If the Customer receives a damaged or incorrect item, it must be reported within 5 (five) working days from delivery, by email or telephone, clearly stating the issue.

Uncollected Parcels, Storage, and International Shipments

It is the Customer’s responsibility to monitor the shipment and promptly arrange for collection or customs clearance.
Any costs, delays, or losses resulting from:

  • failure to collect the parcel,
  • prolonged storage,
  • abandonment of the parcel at customs,

do not entitle the Customer to any refund.

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.