{"product_id":"ifi-dc-blocker-dc-offset-voltage-blocker","title":"iFi DC Blocker + DC Offset Voltage Blocker","description":"\u003ch2\u003eWhat You Need to Know\u003c\/h2\u003e\n\u003ch3\u003eWhat Is the iFi DC Blocker+?\u003c\/h3\u003e\n\u003cp\u003eIf you’ve ever put your ear close to your amplifier and heard a low, steady hum coming from inside the chassis, you’re not imagining things. That mechanical hum is usually caused by your amplifier’s power transformer vibrating. And the reason it vibrates? A small amount of DC (direct current) voltage that shouldn’t be there has snuck into your AC mains power.\u003c\/p\u003e\n\u003cp\u003eHere’s the short version: Your wall outlet is supposed to deliver pure AC power that alternates evenly around zero volts. But in the real world, various appliances, dimmers, motors, and other devices on your electrical circuit can create a DC offset—a slight imbalance in the AC waveform. When that offset reaches your amplifier’s toroidal transformer, the transformer becomes “saturated” and starts to hum.\u003c\/p\u003e\n\u003cp\u003eThe iFi DC Blocker+ is a small, clever device that plugs right into the IEC power inlet on the back of your amplifier (that’s the rectangular socket where your power cord connects). It sits between your power cord and your equipment, and it blocks any DC voltage from getting through. No DC means no transformer saturation, and no saturation means no hum. It’s that simple.\u003c\/p\u003e\n\u003ch3\u003eWhy Does It Matter?\u003c\/h3\u003e\n\u003cp\u003eThe DC Blocker+ uses iFi’s ZERO DC Block technology to block incoming DC up to 1,200 millivolts. That’s enough to handle the vast majority of DC offset problems found in residential power. And it does this without affecting the AC power your equipment needs to operate normally.\u003c\/p\u003e\n\u003cp\u003eThis is the “+” (plus) version, which means it’s designed for high-power equipment. With a continuous current rating of 10A and a maximum current rating of up to 14A, it can handle large amplifiers with big toroidal transformers—exactly the kind of equipment most prone to DC-related hum. It supports amplifiers drawing up to 1,100 watts on a 110V circuit (or 2,200 watts on 220V).\u003c\/p\u003e\n\u003cp\u003eThe DC Blocker+ also retains EMI (electromagnetic interference) shielding, so it’s not just blocking DC—it’s maintaining protection against radio-frequency noise too. The hospital-grade IEC connectors ensure a solid, reliable connection, and the entire unit is UL listed with flame-resistant materials (UL94-V0 rated).\u003c\/p\u003e\n\u003cp\u003eAt just 3 inches long and 2.8 ounces, it’s compact enough that it won’t block neighboring power sockets or put strain on your equipment’s IEC inlet.\u003c\/p\u003e\n\u003ch3\u003eAn Important Note: What It Does and Doesn’t Fix\u003c\/h3\u003e\n\u003cp\u003eThe DC Blocker+ is specifically designed to eliminate mechanical transformer hum caused by DC offset on the mains. This is the hum you hear coming from inside the chassis of your amplifier, not from your speakers.\u003c\/p\u003e\n\u003cp\u003eIt will \u003cstrong\u003enot\u003c\/strong\u003e fix hum caused by ground loops (buzzing from your speakers), phono stage interference, cable faults, or gain-mismatch hiss. If your hum is coming through your speakers rather than from the amplifier chassis itself, the issue is likely something else. Not sure which kind of hum you have? Give us a call at 800-942-0220 and we’ll help you diagnose it.\u003c\/p\u003e\n\u003ch3\u003eWho Is This Best For?\u003c\/h3\u003e\n\u003cp\u003e\u003cimg class=\"emoji\" role=\"img\" draggable=\"false\" src=\"https:\/\/s.w.org\/images\/core\/emoji\/17.0.2\/svg\/2714.svg\" alt=\"✔️\" width=\"15\"\u003e Your amplifier or integrated amp has a noticeable mechanical hum coming from inside the chassis, especially when the room is quiet.\u003c\/p\u003e\n\u003cp\u003e\u003cimg class=\"emoji\" role=\"img\" draggable=\"false\" src=\"https:\/\/s.w.org\/images\/core\/emoji\/17.0.2\/svg\/2714.svg\" alt=\"✔️\" width=\"15\"\u003e You have a large amplifier with a toroidal transformer that’s particularly sensitive to DC on the mains.\u003c\/p\u003e\n\u003cp\u003e\u003cimg class=\"emoji\" role=\"img\" draggable=\"false\" src=\"https:\/\/s.w.org\/images\/core\/emoji\/17.0.2\/svg\/2714.svg\" alt=\"✔️\" width=\"15\"\u003e You live in an area with “dirty” power—older wiring, shared circuits with heavy appliances, or frequent dimmer switch use nearby.\u003c\/p\u003e\n\u003cp\u003e\u003cimg class=\"emoji\" role=\"img\" draggable=\"false\" src=\"https:\/\/s.w.org\/images\/core\/emoji\/17.0.2\/svg\/2714.svg\" alt=\"✔️\" width=\"15\"\u003e You want a simple, plug-and-play solution that doesn’t require any wiring, tools, or modifications to your equipment.\u003c\/p\u003e\n\u003cp\u003e\u003cimg class=\"emoji\" role=\"img\" draggable=\"false\" src=\"https:\/\/s.w.org\/images\/core\/emoji\/17.0.2\/svg\/2714.svg\" alt=\"✔️\" width=\"15\"\u003e You need a DC blocker rated for high-power equipment (10A continuous) rather than lighter-duty devices.\u003c\/p\u003e\n\u003ch3\u003eHow Does It Connect?\u003c\/h3\u003e\n\u003cp\u003eInstallation could not be easier. Unplug your power cord from the back of your amplifier. Plug the DC Blocker+ into the IEC inlet on your amp. Then plug your power cord into the DC Blocker+. That’s it—you’re done. No tools, no settings, no configuration. It’s a “fit and forget” solution.\u003c\/p\u003e\n\u003cp\u003eThe DC Blocker+ works with any equipment that uses a standard IEC power connector (the three-prong rectangular socket found on most amplifiers, receivers, DACs, and other audio components). It’s globally compatible with voltages from 90V to 250V.\u003c\/p\u003e\n\u003cp\u003eIf you also have a ground loop problem, iFi makes a separate product called the GND Defender that can be used in combination with the DC Blocker+.\u003c\/p\u003e\n\u003ch3\u003eWhat’s in the Box\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eiFi DC Blocker+ unit\u003c\/li\u003e\n\u003cli\u003eProduct documentation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhat Are Reviewers Saying?\u003c\/h3\u003e\n\u003cp\u003e\u003cem\u003eProfessional reviews of the DC Blocker+ specifically are limited, but the original iFi DC Blocker has been well received by the audio press.\u003c\/em\u003e\u003c\/p\u003e\n\u003cdiv class=\"ec-blockquote\"\u003e\n\u003cp\u003e\u003cstrong\u003ePositive Feedback\u003c\/strong\u003e — July 2021\u003c\/p\u003e\n\u003cp\u003ePositive Feedback reviewed the original iFi DC Blocker alongside the GND Defender. The reviewer confirmed it effectively eliminated mechanical transformer hum on a Forte Model 3 amplifier and praised its simple IEC-to-IEC installation and compact size.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch3\u003ePairs Well With\u003c\/h3\u003e\n\u003cp\u003eBuilding a quieter system? Here are some great companions:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eiFi GND Defender\u003c\/strong\u003e — If you have both transformer hum and ground loop buzz, the GND Defender tackles the ground loop side. Use both together for the quietest background.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower Cables\u003c\/strong\u003e — A quality power cable between the DC Blocker+ and your equipment completes the chain. Browse our \u003ca href=\"%%GLOBAL_ShopPathSSL%%\/power-cables\"\u003ePower Cables\u003c\/a\u003e.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower Conditioners\u003c\/strong\u003e — For full-system power protection and conditioning, browse our \u003ca href=\"%%GLOBAL_ShopPathSSL%%\/power-conditioners\"\u003ePower Conditioners\u003c\/a\u003e.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFeatures \u0026amp; Specifications—Benefit-Driven\u003c\/h3\u003e\n\u003ch4\u003eDC Blocking Performance\u003c\/h4\u003e\n\u003cp\u003e\u003cstrong\u003eZERO DC Block Technology\u003c\/strong\u003e — iFi’s proprietary technology blocks incoming DC voltage up to 1,200 millivolts. This eliminates the root cause of mechanical transformer hum in amplifiers and other audio equipment with toroidal power supplies.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHigh-Power Rating\u003c\/strong\u003e — With a continuous current rating of 10A and a maximum rating of up to 14A, the DC Blocker+ handles large, powerful amplifiers without breaking a sweat. It supports equipment drawing up to 1,100W on 110V circuits or 2,200W on 220V circuits.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eEMI Shielding Retained\u003c\/strong\u003e — The DC Blocker+ doesn’t just block DC—it also maintains electromagnetic interference shielding, helping keep radio-frequency noise out of your system.\u003c\/p\u003e\n\u003ch4\u003eSafety \u0026amp; Build\u003c\/h4\u003e\n\u003cp\u003e\u003cstrong\u003eHospital-Grade IEC Connectors\u003c\/strong\u003e — Premium connectors ensure a solid, reliable connection to your equipment’s power inlet.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eUL Listed\u003c\/strong\u003e — Independently tested and certified for safety.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFlame-Resistant Materials\u003c\/strong\u003e — The IEC socket, connector, and chassis use fireproof polymers rated UL94-V0.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHigh Dielectric Strength\u003c\/strong\u003e — Rated at 1,500 VRMS for reliable insulation between circuits.\u003c\/p\u003e\n\u003ch4\u003eDesign\u003c\/h4\u003e\n\u003cp\u003e\u003cstrong\u003eCompact and Lightweight\u003c\/strong\u003e — At just 3″ × 1.8″ × 1.3″ and 2.8 ounces, the DC Blocker+ won’t obstruct neighboring power sockets, cables, or connectors. It won’t strain your equipment’s IEC inlet either.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGlobally Compatible\u003c\/strong\u003e — Works with voltages from 90V to 250V, so it functions anywhere in the world.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePlug-and-Play Installation\u003c\/strong\u003e — No tools, no settings, no modifications. Just plug it in between your power cord and your equipment.\u003c\/p\u003e\n\u003ch3\u003eQuick-Reference Specifications\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; font-size: 0.92em; margin-top: 16px;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\" colspan=\"2\"\u003eDC Blocking Performance\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\"\u003eTechnology\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #ddd;\"\u003eZERO DC Block — blocks incoming DC up to 1,200 mV\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\"\u003eVoltage Rating\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #ddd;\"\u003e90 – 250 V (globally compatible)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\"\u003eMaximum Current Rating\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #ddd;\"\u003e≤14 A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\"\u003eContinuous Current Rating\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #ddd;\"\u003e10 A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\"\u003eMax Amplifier Power\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #ddd;\"\u003e1,100 W (110V~) \/ 2,200 W (220V~)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\" colspan=\"2\"\u003eSafety \u0026amp; Build\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\"\u003eSemiconductor\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #ddd;\"\u003eHigh-performance glass passivated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\"\u003eDielectric Strength\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #ddd;\"\u003e1,500 VRMS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\"\u003eConnectors\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #ddd;\"\u003eHospital-grade IEC (in\/out)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\"\u003eSafety Certifications\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #ddd;\"\u003eUL listed; flame-resistant chassis (UL94-V0)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\"\u003eEMI Shielding\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #ddd;\"\u003eRetained\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\" colspan=\"2\"\u003eDimensions \u0026amp; Weight\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\"\u003eDimensions\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #ddd;\"\u003e75 × 46 × 32 mm (3.0″ × 1.8″ × 1.3″)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 8px 12px; font-weight: 600; border-bottom: 1px solid #ddd; width: 45%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 12px; border-bottom: 1px solid #ddd;\"\u003e2.8 oz (~79 g)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cdiv class=\"product-faq gsbp-ab3b28d\"\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003chr\u003e\n\u003ch3\u003eMy amplifier hums. Will the DC Blocker+ fix it?\u003c\/h3\u003e\n\u003cp\u003eIf the hum is a mechanical vibration coming from inside your amplifier’s chassis (from the transformer itself), and it’s caused by DC offset on your mains power, then yes—the DC Blocker+ is designed to eliminate exactly that. If the hum or buzz is coming from your speakers, that’s usually a ground loop or cable issue, which the DC Blocker+ won’t fix. Not sure? Give us a call and we’ll help you figure it out.\u003c\/p\u003e\n\u003ch3\u003eHow do I install it?\u003c\/h3\u003e\n\u003cp\u003eUnplug your power cord from the back of your amplifier. Plug the DC Blocker+ into your amp’s IEC inlet. Then plug your power cord into the DC Blocker+. That’s it—no tools, no settings, no configuration needed.\u003c\/p\u003e\n\u003ch3\u003eWhat’s the difference between the DC Blocker and the DC Blocker+?\u003c\/h3\u003e\n\u003cp\u003eThe DC Blocker+ is the higher-rated version. It has a continuous current rating of 10A (vs. 4A for the standard DC Blocker) and supports equipment drawing up to 1,100W on 110V. If you have a large, powerful amplifier with a big toroidal transformer, the DC Blocker+ is the better choice. The standard DC Blocker works fine for smaller components like DACs, preamps, and streamers.\u003c\/p\u003e\n\u003ch3\u003eWill it affect the sound quality of my system?\u003c\/h3\u003e\n\u003cp\u003eThe DC Blocker+ is designed to block DC without restricting the AC power your equipment needs. It retains EMI shielding and doesn’t alter or condition the AC signal in ways that would degrade audio performance. Many users report that eliminating transformer hum reveals a quieter background, which can make subtle details in the music more noticeable.\u003c\/p\u003e\n\u003ch3\u003eCan I use it with any audio equipment?\u003c\/h3\u003e\n\u003cp\u003eYes, as long as the equipment uses a standard IEC power connector (the rectangular three-prong socket found on most amps, receivers, DACs, and power conditioners). The DC Blocker+ works with voltages from 90V to 250V, so it’s compatible worldwide.\u003c\/p\u003e\n\u003ch3\u003eCan I use the DC Blocker+ and the GND Defender together?\u003c\/h3\u003e\n\u003cp\u003eYes. If you have both mechanical transformer hum (from DC offset) and ground loop buzz (from your speakers), you can use both. The recommended order from the wall is: power cable → DC Blocker+ → GND Defender → equipment IEC inlet.\u003c\/p\u003e\n\u003ch3\u003eIs the DC Blocker+ safe to use?\u003c\/h3\u003e\n\u003cp\u003eYes. It’s UL listed, uses flame-resistant materials rated UL94-V0, and has hospital-grade IEC connectors. It does not affect the safety or integrity of your equipment in any way.\u003c\/p\u003e\n\u003ch3\u003eWill it put strain on my equipment’s IEC inlet?\u003c\/h3\u003e\n\u003cp\u003eAt just 2.8 ounces, the DC Blocker+ is extremely light. It won’t put meaningful strain on your equipment’s power inlet or on the power cord connection.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch3\u003eWhy Audio Advisor?\u003c\/h3\u003e\n\u003cdiv class=\"ec-titlebox-text\"\u003e\n\u003cp\u003e\u003cimg class=\"emoji\" role=\"img\" draggable=\"false\" src=\"https:\/\/s.w.org\/images\/core\/emoji\/17.0.2\/svg\/1f3b5.svg\" alt=\"music note emoji\" width=\"20\"\u003e \u003cstrong\u003e40+ Years of Expertise\u003c\/strong\u003e — Since 1981, we’ve helped over a million music lovers find the right gear.\u003c\/p\u003e\n\u003cp\u003e\u003cimg class=\"emoji\" role=\"img\" draggable=\"false\" src=\"https:\/\/s.w.org\/images\/core\/emoji\/17.0.2\/svg\/1f504.svg\" alt=\"repeat emoji\" width=\"20\"\u003e \u003cstrong\u003e60-Day Money-Back Guarantee\u003c\/strong\u003e — Take your time. Listen, enjoy, and make sure it’s right for you.\u003c\/p\u003e\n\u003cp\u003e\u003cimg class=\"emoji\" role=\"img\" draggable=\"false\" src=\"https:\/\/s.w.org\/images\/core\/emoji\/17.0.2\/svg\/1f4de.svg\" alt=\"phone emoji\" width=\"20\"\u003e \u003cstrong\u003eReal Experts, Real Help\u003c\/strong\u003e — Our team is here to answer your questions at \u003ca href=\"tel:8009420220\"\u003e800-942-0220\u003c\/a\u003e, weekdays 9am–6pm EST.\u003c\/p\u003e\n\u003cp\u003e\u003cimg class=\"emoji\" role=\"img\" draggable=\"false\" src=\"https:\/\/s.w.org\/images\/core\/emoji\/17.0.2\/svg\/1f69a.svg\" alt=\"truck emoji\" width=\"20\"\u003e \u003cstrong\u003eFree Shipping\u003c\/strong\u003e — On orders over $49, delivered to your door.\u003c\/p\u003e\n\u003cp\u003e\u003cimg class=\"emoji\" role=\"img\" draggable=\"false\" src=\"https:\/\/s.w.org\/images\/core\/emoji\/17.0.2\/svg\/1f4b3.svg\" alt=\"credit card emoji\" width=\"20\"\u003e \u003cstrong\u003eFlexible Payment Options\u003c\/strong\u003e — Financing available so you can start listening now.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch3\u003eLearn More\u003c\/h3\u003e\n\u003cp\u003eWant to learn more about power quality and how it affects your audio system? Visit our \u003ca href=\"https:\/\/learningcenter.audioadvisor.com\/\"\u003eLearning Center\u003c\/a\u003e for guides, tips, and expert advice.\u003c\/p\u003e","brand":"iFi Audio","offers":[{"title":"New","offer_id":46017141309613,"sku":"NEW-IFDCBLOC+","price":149.0,"currency_code":"USD","in_stock":true},{"title":"Demo","offer_id":46017141342381,"sku":"DEMO-IFDCBLOC+","price":149.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0750\/3708\/1773\/files\/ifi-dc-blocker-plus-connect__13887.1779975785.1280.1280.jpg?v=1781095559","url":"https:\/\/www.audioadvisor.com\/products\/ifi-dc-blocker-dc-offset-voltage-blocker","provider":"Audio Advisor","version":"1.0","type":"link"}