KR Audio
Expected Oct 10, 2025
274B Vacuum Tube
$685.00 USDThe KR Audio 274B rectifier tube is a high-end full-wave thermionic vacuum tube that sets the standard for exceptional performance and audiophile-grade sound quality. This meticulously crafted tube is designed to elevate your audio experience by providing a stable, regular voltage and superior current rectification, ensuring that your amplifier delivers the rich, detailed & Musical sound you demand. Ideal for use in tube amplifiers & preamplifiers, the KR Audio 274B is a versatile addition to any hi-fi setup.
The KR Audio 274B is the result of years of research and development, combining advanced engineering with the finest materials and filaments to create a rectifier tube that stands head and shoulders above the competition. Its superior design ensures long life and reliable operation, making it the perfect choice for discerning audiophiles who refuse to compromise on sound quality. At the heart of the KR Audio 274B's outstanding performance is its ability to deliver a stable, regular voltage to your amplifier's circuit. By providing a clean and consistent power supply, this tube allows your amplifier to operate at its full potential, reproducing music with unparalleled clarity, dynamics, and emotional impact.
The 274B's excellent current rectification capabilities ensure that your amplifier has the necessary power to handle even the most demanding musical passages with ease. This tube's superior rectification process minimizes voltage drops and reduces noise, resulting in a cleaner, more transparent sound that brings out the best in your favorite recordings. Available in variations such as the 5U4G rectifier vacuum tube, GE 5U4GA, and RCA 5U4GB, and produced by renowned manufacturers like Electro-Harmonix, Western Electric, Sophia Electric, Sylvania, and Takatsuki, this new production tube maintains the heritage of high-quality USA-made power tubes. We consider the KR Audio version one of the best on the market.
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.
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 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 | 4.0 V |
| Filament Current | 1.1 A |
| Amplification Factor | 5.0 |
| Maximum Ratings | |
| DC Plate Voltage | 350 V |
| DC Plate Current | 100 mA |
| Plate Dissipation | 20 Watts |
| Operating Specifications | |
| DC Plate Voltage (Testing Point) | 250 V |
| DC Plate Current (Testing Point) | 48 mA |
| Grid Voltage (Testing Point) | -32 V |
| Performance Specifications | |
| Plate Resistance | 980 ohms |
| Transconductance | 5.1 mA/V |