iFi SilentPower DC Blocker - Blocks any DC offset, IEC Connector

Product Information

Enhanced performance for power amplifiers, offering a consistently clean and efficient power supply. The AC transformers commonly used in home audio equipment cannot tolerate the presence of significant levels of DC voltage without being compromised. Less than 500mV of DC – typical in an average household electricity supply – can be sufficient to cause toroidal transformers of the kind often found in amplifiers to become saturated, which adversely affects sonic performance and may cause audible mechanical vibration.

There are a few older household appliances that can create a DC offset, although most are (probably) no longer permitted due to increasing problems caused by the DC component. This is more than compensated by various industrial processes, which for one reason or another manage to unbalance the mains supply sufficiently to cause problems. Even the simple act of turning on a large transformer causes a period of asymmetry... see Transformers, Part 2, Section 12.2, Inrush Current for details on this phenomenon. 'Sympathetic interaction' is a very real phenomenon. Inrush current can be very much higher than the nominal full power current, so the capacitor(s) require protection against over-current. The simplest has already been mentioned - the diodes that limit the maximum voltage across the caps will also limit the capacitor current. As current increases, so too does the voltage across the capacitors. The diodes will conduct if the voltage exceeds the forward voltage of either pair of the two series diodes. These diodes must be capable of withstanding the maximum peak current expected. This may exceed 50A for a brief period, and again, use a soft-start circuit! The actual problem is not that everything should be designed as optimal as possible. It should be designed good enough. Sonic improvements promised by the SupaNova power cable include greater clarity and definition plus enhanced dynamic range.In 2010 audiolab began the introduction of its latest full-width 8200 Series components, combining the company’s original ethos of simple, well-constructed ergonomics and crisp, transparent sound with innovative, performance-led design concepts. With a quieter mains signal being feed to your amplifier, the whole system benefits. A quieter amp means less distortion relayed to other components, helping reduce distortion and enhance music dynamics. The circuit as shown will also work perfectly with 120V 60Hz, but it would be wise to increase the capacitance (double the value shown here). Although the caps will work better with the higher frequency, the transformer idle current will be higher than that of a 220-240V transformer. While studying various designs I stumbled across a TEAC DAC, that I personally found interesting as it took a grip of the dirty USB cable shield. It lands the USB port at separate pcb, hard coupled to chassis by a screw and just millimeters from the port, minimizing the lead reactans, the entire PCB is grounded to chassis. This is an example of a good design. Others in that DAC could be questioned in my opinion. Could not see, e.g. any signs of a grounded lead out from an electrostatic shield in the transformers.

Mains electricity has a fundamental influence on the audio signal as it passes through a system, from source to amplifiers to speakers. The mains supply in a typical home is subject to interference induced by a range of issues, causing the AC waveform to distort before it reaches each component. This creates noise in the audio signal, which degrades sound quality – a situation that continues to worsen with more and more electrical devices being added to the home mains supply. Conflict of interest statement: The author declares no conflicts of interest regarding this article. The method for DC injection shown above (a half wave rectified load), while quite realistic, has the disadvantage of being somewhat uncontrolled. In addition, I don't have any hot air blowers that use a diode for half power, so the test used was somewhat different from the description. Instead of the half-wave load, I used a small power supply, and actually injected DC in series with the incoming mains. The test setup is shown in Figure 6, and it allowed me to have complete control over the parameters during the tests.

PH15, PH16, PH17, PH18, PH19, PH20, PH21, PH22, PH23, PH24, PH25, PH26, PH27, PH28, PH29, PH30, PH31, PH32, PH33, PH34, PH35, PH36, PH37, PH38, PH39, PH40, PH41, PH42, PH43, PH44, PH45, PH46, PH47, PH48, PH49, PH50

Most of the time, the DC offset is transient - it appears for a short while, then goes away again. When it is there, toroidal transformers may complain loudly by making growling or buzzing noises. It is important to understand just how this happens, and what can be done about it if it causes problems. circuit (see Figure 8) is easily adapted - the changes needed are described in the conclusion text. The mains voltage is more-or-less immaterial unless it climbs by more While the circuit is shown connected in the active (live) line, it makes no difference whether it's in the active or neutral. This also applies to electrical safety - all electrical codes classify the neutral as a hazardous conductor, because there are so many way that active and neutral can be reversed. The same level of insulation is required regardless of where the circuit is placed electrically, and any claim you see that it's somehow 'safer' in the neutral line is simply untrue. In theory it's true, but in reality active and neutral are classified as being equally dangerous.Going IEC to IEC keeps the cost down, as there are many AC wall plug configurations around the world, but most modern gear with detachable power cords run with IEC on the equipment end. If you have problematic older/cheaper gear with odd-ball or captive power cords, you can of course have a qualified tech install an IEC input. In the US, you might also consider bookending the iFi cubes with AC to IEC adapters such as the C13 to NEMA 15-5 and NEMA 15-5 to C14.

injury. By reading past this point, you explicitly accept all responsibility for any such death or injury, and hold Elliott Sound Products harmless against litigation or prosecution even Six independent outlets for source components; power amps, preamps, integrated amplifiers, CD players, DACs, etc.A surge protection with 250V rated varistor and 10A fuse (Schurter Slow-blow type) is incorporated at the AC input. AB31, AB32, AB33, AB34, AB35, AB36, AB37, AB38, AB41, AB42, AB43, AB44, AB45, AB46, AB47, AB48, AB49, AB50, AB51, AB52, AB53, AB54, AB55, AB56 reduced. With a continuous current, the capacitance needs to be large enough to support the continuous current. As before, inrush current is not a problem, and the diodes will conduct A varying DC offset on the AC mains is no longer uncommon. There are many ways that a DC offset can be created, with most being totally outside the control of those who have to try to eliminate it, or put up with the mechanical noise created in (especially) toroidal transformers. It may be counter-intuitive (and some may choose to disbelieve it altogether [they are wrong]), but the maximum flux density in any transformer core occurs at no load. This is also the condition where even a small DC offset can cause the idle current to rise alarmingly, as described further below.