{"product_id":"2a3-tube-pair","title":"2A3 Vacuum Tube","description":"\u003cbuilder-component rev=\"xtyqk7nfsb\" api-key=\"48d1cdcd52ec4d289f1ef8c4f75da167\" options='{\"locale\":\"Default\"}' name=\"product-description\" entry=\"388f596043fb4bbea5c53410dfaff2fe\"\u003e\n\n\u003c!-- ***** Generated by Builder.io on Fri, 18 Jul 2025 14:20:18 GMT ***** --\u003e\n\n\u003cstyle type=\"text\/css\" class=\"builder-styles builder-api-styles\"\u003e\/*start:h47494*\/.css-h47494{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;-webkit-align-items:stretch;-webkit-box-align:stretch;-ms-flex-align:stretch;align-items:stretch;}\/*end:h47494*\/ \/*start:ga7wz6*\/.css-ga7wz6.builder-block{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;position:relative;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;box-sizing:border-box;margin-top:0px;margin-left:auto;margin-right:auto;max-width:800px;}\/*end:ga7wz6*\/ \/*start:1840m1q*\/.css-1840m1q{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;}@media (max-width:999px){.css-1840m1q{-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;-webkit-align-items:stretch;-webkit-box-align:stretch;-ms-flex-align:stretch;align-items:stretch;}}\/*end:1840m1q*\/ \/*start:1ukkadj*\/.css-1ukkadj{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;-webkit-align-items:stretch;-webkit-box-align:stretch;-ms-flex-align:stretch;align-items:stretch;line-height:normal;width:calc(100% - 0px);margin-left:0;}.css-1ukkadj \u003e .builder-blocks{-webkit-box-flex:1;-webkit-flex-grow:1;-ms-flex-positive:1;flex-grow:1;}@media (max-width:999px){.css-1ukkadj{width:100%;margin-left:0;}}\/*end:1ukkadj*\/ \/*start:qcdo0v*\/.css-qcdo0v.builder-block{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;position:relative;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;box-sizing:border-box;margin-top:0px;line-height:normal;height:auto;}\/*end:qcdo0v*\/ \/*start:1qggkls*\/.css-1qggkls{outline:none;}.css-1qggkls p:first-of-type,.css-1qggkls .builder-paragraph:first-of-type{margin:0;}.css-1qggkls \u003e p,.css-1qggkls .builder-paragraph{color:inherit;line-height:inherit;-webkit-letter-spacing:inherit;-moz-letter-spacing:inherit;-ms-letter-spacing:inherit;letter-spacing:inherit;font-weight:inherit;font-size:inherit;text-align:inherit;font-family:inherit;}\/*end:1qggkls*\/ \/*start:hgfgng*\/.css-hgfgng.builder-block{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;position:relative;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;box-sizing:border-box;margin-top:20px;line-height:normal;height:auto;}\/*end:hgfgng*\/ \/*start:ur9nhf*\/.css-ur9nhf.builder-block{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;position:relative;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;box-sizing:border-box;margin-top:20px;height:2px;background-color:rgba(221,221,221,1);}\/*end:ur9nhf*\/ \/*start:1mvsfya*\/.css-1mvsfya.builder-block{height:0;width:0;display:inline-block;opacity:0;overflow:hidden;pointer-events:none;}\/*end:1mvsfya*\/\u003c\/style\u003e\n\u003cdiv class=\"builder-component builder-component-388f596043fb4bbea5c53410dfaff2fe\" data-name=\"product-description\" data-source=\"Rendered by Builder.io\"\u003e\u003cdiv class=\"builder-content\" builder-content-id=\"388f596043fb4bbea5c53410dfaff2fe\" builder-model=\"product-description\"\u003e\u003cdiv data-builder-component=\"product-description\" data-builder-content-id=\"388f596043fb4bbea5c53410dfaff2fe\" data-builder-variation-id=\"388f596043fb4bbea5c53410dfaff2fe\"\u003e\n\u003cstyle data-emotion-css=\"h47494\"\u003e\u003c\/style\u003e\n\u003cdiv class=\"builder-blocks css-h47494\" builder-type=\"blocks\"\u003e\n\u003cstyle data-emotion-css=\"ga7wz6\"\u003e\u003c\/style\u003e\n\u003cdiv class=\"builder-block builder-38356bdcea0646d69bd145a185549319 builder-has-component css-ga7wz6\" builder-id=\"builder-38356bdcea0646d69bd145a185549319\"\u003e\n\u003cstyle data-emotion-css=\"1840m1q\"\u003e\u003c\/style\u003e\n\u003cdiv class=\"builder-columns css-1840m1q\"\u003e\n\u003cstyle data-emotion-css=\"1ukkadj\"\u003e\u003c\/style\u003e\n\u003cdiv class=\"builder-column css-1ukkadj\"\u003e\u003cdiv class=\"builder-blocks builder-blocks-child css-h47494\" builder-type=\"blocks\"\u003e\n\u003cstyle data-emotion-css=\"qcdo0v\"\u003e\u003c\/style\u003e\n\u003cdiv class=\"builder-block builder-26e45f51c0644bf096a01259fb64c52c builder-has-component css-qcdo0v\" builder-id=\"builder-26e45f51c0644bf096a01259fb64c52c\"\u003e\n\u003cstyle data-emotion-css=\"1qggkls\"\u003e\u003c\/style\u003e\n\u003cspan class=\"builder-text css-1qggkls\"\u003e\u003cp\u003eIntroducing 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.\u003c\/p\u003e\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cstyle data-emotion-css=\"hgfgng\"\u003e\u003c\/style\u003e\n\u003cdiv class=\"builder-block builder-d2f937ac9442480ab742051bf886ecd0 builder-has-component css-hgfgng\" builder-id=\"builder-d2f937ac9442480ab742051bf886ecd0\"\u003e\u003cspan class=\"builder-text css-1qggkls\"\u003e\u003cp\u003eThe 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.\u003c\/p\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv class=\"builder-block builder-b3de35ccf9654ed695e5831d013166c4 builder-has-component css-hgfgng\" builder-id=\"builder-b3de35ccf9654ed695e5831d013166c4\"\u003e\u003cspan class=\"builder-text css-1qggkls\"\u003e\u003cp\u003eThe 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.\u003c\/p\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv class=\"builder-block builder-764c61f976d147b886ab39398408f126 builder-has-component css-hgfgng\" builder-id=\"builder-764c61f976d147b886ab39398408f126\"\u003e\u003cspan class=\"builder-text css-1qggkls\"\u003e\u003ch3\u003eKR Audio WARRANTY ON TUBES ONLY \u003c\/h3\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv class=\"builder-block builder-67d5f22a389e4904b0a94b7809d50dcc builder-has-component css-hgfgng\" builder-id=\"builder-67d5f22a389e4904b0a94b7809d50dcc\"\u003e\u003cspan class=\"builder-text css-1qggkls\"\u003e\u003cp\u003ePlease 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. \u003c\/p\u003e\n\u003cp\u003eKR 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: \u003c\/p\u003e\n\u003col\u003e\n\u003cli\u003eThe tubes were used according to the technical data sheet enclosed with the KR tube. \u003c\/li\u003e\n\u003cli\u003eAbuse, accident or unauthorized use of the tube will be determined by KR Audio Electronics. \u003c\/li\u003e\n\u003cli\u003eAll tubes to be returned with the original factory box and warranty. \u003c\/li\u003e\n\u003cli\u003eTo 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. \u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003eKR 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. \u003c\/p\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cstyle data-emotion-css=\"ur9nhf\"\u003e\u003c\/style\u003e\n\u003cdiv class=\"builder-block builder-81a2889fad504de58095da8917a6b28a css-ur9nhf\" builder-id=\"builder-81a2889fad504de58095da8917a6b28a\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"builder-block builder-1b9013eea0354cef82e14d66dc05944c builder-has-component css-hgfgng\" builder-id=\"builder-1b9013eea0354cef82e14d66dc05944c\"\u003e\u003cspan class=\"builder-text css-1qggkls\"\u003e\u003ch3\u003eAbout the 2A3 Tube: A Legendary Directly Heated Power Triode\u003c\/h3\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv class=\"builder-block builder-5e0292970fc74e4892cd0c140f41baef builder-has-component css-hgfgng\" builder-id=\"builder-5e0292970fc74e4892cd0c140f41baef\"\u003e\u003cspan class=\"builder-text css-1qggkls\"\u003e\u003cp\u003eThe 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.\u003c\/p\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv class=\"builder-block builder-bb459dc909cb45f082cfa66a634f3c87 builder-has-component css-hgfgng\" builder-id=\"builder-bb459dc909cb45f082cfa66a634f3c87\"\u003e\u003cspan class=\"builder-text css-1qggkls\"\u003e\u003cp\u003eAs 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.\u003c\/p\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv class=\"builder-block builder-d596d77a1623497a85b3c61ca930e775 builder-has-component css-hgfgng\" builder-id=\"builder-d596d77a1623497a85b3c61ca930e775\"\u003e\u003cspan class=\"builder-text css-1qggkls\"\u003e\u003cp\u003eThe 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.\u003c\/p\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv class=\"builder-block builder-e0a177dbae0d46c6b180fc7ee3badde9 builder-has-component css-hgfgng\" builder-id=\"builder-e0a177dbae0d46c6b180fc7ee3badde9\"\u003e\u003cspan class=\"builder-text css-1qggkls\"\u003e\u003cp\u003eAudiophiles 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.\"\u003c\/p\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv class=\"builder-block builder-7689f309e096496ba7e93cc528520739 builder-has-component css-hgfgng\" builder-id=\"builder-7689f309e096496ba7e93cc528520739\"\u003e\u003cspan class=\"builder-text css-1qggkls\"\u003e\u003cp\u003eMany 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.\u003c\/p\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv class=\"builder-block builder-bc960cde177941edaca730017cae0f8d builder-has-component css-hgfgng\" builder-id=\"builder-bc960cde177941edaca730017cae0f8d\"\u003e\u003cspan class=\"builder-text css-1qggkls\"\u003e\u003cp\u003eDespite 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.\u003c\/p\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv class=\"builder-block builder-5d0cb6e0722e4f2e9c3e43694c35c5a0 css-ur9nhf\" builder-id=\"builder-5d0cb6e0722e4f2e9c3e43694c35c5a0\"\u003e\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cstyle data-emotion-css=\"1mvsfya\"\u003e\u003c\/style\u003e\n\u003cimg src=\"https:\/\/cdn.builder.io\/api\/v1\/pixel?apiKey=48d1cdcd52ec4d289f1ef8c4f75da167\" aria-hidden=\"true\" alt=\"\" role=\"presentation\" width=\"0\" height=\"0\" class=\"builder-block builder-pixel-kbluty8e5o8 css-1mvsfya\" builder-id=\"builder-pixel-kbluty8e5o8\"\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/div\u003e\u003c\/div\u003e\u003c\/builder-component\u003e\n\u003cscript async src=\"https:\/\/cdn.builder.io\/js\/webcomponents\"\u003e\u003c\/script\u003e","brand":"KR Audio","offers":[{"title":"Pair ($1150)","offer_id":49668540465466,"sku":"2A3-KRM-1","price":1150.0,"currency_code":"USD","in_stock":true},{"title":"Quad ($2300)","offer_id":49668540498234,"sku":"2A3-KRM-2","price":2300.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0834\/0245\/7402\/files\/KR_Audio_2A3_Tube_Pair__82290.1715874157.1280.1280.jpg?v=1719257330","url":"https:\/\/www.moon-audio.pro\/products\/2a3-tube-pair","provider":"Moon Audio","version":"1.0","type":"link"}