KR Audio
KR Audio 2A3 Vacuum Tube
$1,150.00 USDFeatures
Fully compatible with any well-designed 2A3 amplifier
Meticulously engineered for pure spatial sense and precise timing cues
Reproduces music with brilliant tone and captivating midrange warmth
Handcrafted by KR Audio for exceptional quality and attention to detail
Rigorously tested and matched for balanced, dynamic performance
Ideal for discerning audiophiles seeking the classic "tube sound"
What's in the Box?
Introducing the KR Audio 2A3 matched pair, a set of two expertly crafted tubes designed to elevate your audio experience to new heights. These low-frequency, low-power triodes deliver an impressive 2-5 Watts of pure class-A power, ensuring your music is reproduced with unparalleled clarity and warmth. This matched pair is meticulously engineered to provide the ultimate sonic experience for discerning audiophiles and music enthusiasts alike.
The KR Audio 2A3 tubes are fully compatible with any well-designed 2A3 amplifier, making them the perfect upgrade for your existing setup. These tubes deliver exactly what owners of these special amplifiers expect: a pure sense of space, perfect subtle timing cues, and a brilliant tone that will transport you to the heart of your favorite recordings.
The 2A3 tubes offer a level of performance that sets them apart from the competition, thanks to KR Audio's commitment to quality and attention to detail. Whether you're a seasoned audiophile or simply appreciate the finer things in life, the KR Audio 2A3 tubes are the go-to choice for anyone seeking to elevate their 2A3-based system to new heights. Experience the difference for yourself and discover why these tubes have earned a reputation as the ultimate upgrade for 2A3 enthusiasts worldwide.
KR Audio WARRANTY ON TUBES ONLY
Please take a moment to return your warranty registration form included with the tubes. Unregistered KR tubes will not be warranted. Customers must return the warranty registration when the tubes have been received.
KR Audio Electronics will respect valid warranty claims. Incorrect claims or late warranty registration will void any guarantee. KR Audio Electronics will replace the tube provided the following conditions are met:
- The tubes were used according to the technical data sheet enclosed with the KR tube.
- Abuse, accident or unauthorized use of the tube will be determined by KR Audio Electronics.
- All tubes to be returned with the original factory box and warranty.
- To obtain a replacement for a faulty tube, KR Audio Electronics reserves the right to obtain dealer or distributor authorization prior to shipping products pre-paid back to us.
KR Audio Electronics gives a one-year warranty for your tube from the date of purchase. The purchase date should be written or stamped by the dealer or distributor on the day you buy the tube. Only expert technicians can change the work point of the tube. Improper use of the tube or incorrect application of the tube to a circuit cannot be covered by our warranty.
About the 2A3 Tube: A Legendary Directly Heated Power Triode
The 2A3 tube, a directly heated power triode, has been captivating audiophiles and hifi enthusiasts since its introduction by RCA in the 1930s (and brands like Western Electric and Tung-Sol). This vacuum tube is renowned for its ability to deliver a warm, rich, and naturally textured sound in both power amplifiers and preamplifiers.
As a low-frequency power triode, the 2A3 vacuum tube is capable of producing a modest yet sufficient power output, typically ranging from 2 to 5 watts per tube in single-ended class A configurations. This makes it an ideal choice for high-quality, low-powered tube amplifiers that prioritize sonics over raw power.
The 2A3's filament, which also serves as the cathode, is directly heated (directly heated triode tube), contributing to its unique sonic characteristics. When paired with suitable transformers and circuitry, the 2A3 power vacuum tube can create an incredibly immersive and emotionally engaging listening experience.
Audiophiles and hifi enthusiasts in the USA and around the world praise the 2A3 for its ability to reproduce music with a sense of warmth, intimacy, and naturalness that solid-state devices struggle to match. Its rich midrange, smooth treble, and well-controlled bass make it a favorite among those seeking the quintessential "tube sound."
Many iconic amplifier designs have been built around the 2A3, cementing its position as a legendary tube in the world of high-end audio. These amplifiers often feature minimal components and simple circuits, allowing the 2A3's inherent qualities to shine through. In terms of specs, the 2A3 typically features a maximum plate dissipation of around 15 watts, a filament voltage of 2.5 volts, and a filament current of 2.5 amps. Its amplification factor is approximately 4.2, and its plate resistance is about 800 ohms.
Despite its age, the 2A3 tube remains a popular choice among DIY enthusiasts, boutique tube amp manufacturers, and audio purists who appreciate its timeless design and unrivaled sonic performance. Whether you're building a new tube amplifier or upgrading an existing one, the 2A3 is a vacuum tube that deserves serious consideration.
Moon Audio Tube Testing Process
Our high-end audio systems achieve sonic purity through the use of carefully selected NOS vacuum tubes. We take time to search for NOS tubes, understanding their unique potential for audio reproduction. Each tube is rigorously tested using a legendary HICKOK 800K 600K Dynamic Mutual Conductance Tube Tester and TV7-A/U Vacuum Tube Testers to measure critical parameters, including mutual conductance, emission, and gas levels. By precisely matching tubes based on these measurements, we deliver balanced, dynamic, and lifelike audio that elevates your listening experience to an art form.
| Parameter | Specification |
|---|---|
| Technical Specifications | |
| Filament Voltage | 2.5 V (DC/AC) |
| Filament Current | 2.5 A |
| Amplification Factor | 3.8 |
| Maximum Ratings | |
| Maximum Plate Voltage | 300 V |
| Maximum Plate Current | 100 mA |
| Plate Dissipation | 15 Watts |
| Operating Specifications | |
| Plate Voltage (Va) | 250 V |
| Plate Current (Ia) | 70 mA |
| Grid Voltage (Vg) | -45 V |
| Performance Specifications | |
| Transconductance | 5.2 mA/V |
| Product Specifications | |
| Production Status | New Production, includes warranty |