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Perfect Power Conditioning






In India, many consumers use some form of AC power conditioning to protect electronic equipment, including audio equipment, from surges, fluctuations and other disturbances of the not always (always not?) reliable Indian power grid.


However, many audiophiles in India are not aware of the fact that many of the available solutions (UPS, Net-filter, Surge Protection) impose a profound negative impact on the performance of their connected audio system. The reality is that solutions which are being advertised as protecting equipment, or 'improving' the performance of connected audio systems actually do not. It would take many pages to go completely ‘in-depth’ about this complicated and controversial subject to address the many misconceptions and pseudo science surrounding this subject. However, I will tried to keep it brief and to the point, so forgive me for any shortcuts.


Audio Note India, in general, advices not to use any ‘power conditioning’ or ‘protection’ devices with our products. Equipment with high quality power supplies (such as found in all Audio Note components) don't need UPS’s, filters, protectors, isolation transformers or anything else connected between mains and the system. Chances are they will do more harm than good.


However, in India some real threats are present on the AC feed. Let's see how we can protect our equipment against these threats, while not deteriorating (and maybe even improve) system performance.


Power Disturbances


Typical power disturbances are caused by:


  • Power Surges/Transients;

  • Electromagnetic Interference (EMI);

  • Radio Frequency Interference (RFI);

  • Voltage Fluctuation;

  • Power Disruptions.


Power Surges/Transients


Power Surges/Transients are very brief fluctuations in AC voltage, usually lasting millionths of a second (microseconds), varying in magnitude from a few hundred volts to several thousand volts.


These fluctuations are caused by direct of induced lightening, power grid switching by the provider, faults (end repairs thereof) in the power-grid including in the building itself, and by motors, air-condition equipment, power tools, photo-copiers etc.


Surges are rare (but the grid in India is vulnerable to them), but can cause catastrophic damage to your equipment, while transients are more frequent but less damaging. However transients still can cause digital equipment to freeze, or create audible pops in the audio signal. Over time small spikes and transients can cause overheating and failure of electrical components, while transients limit dynamic range, PRaT and increase background noise. 




This is a general type of electric, radio or magnetic interference which is transmitted by conduction or radiation and can be of a very wide frequency range. Causes are electric motors, transformers, heaters, LED lights, dimmers, power supplies, etc.


These all cause electromagnetic interference, especially at currents above 2A, which lead to buzzing sounds, lack of transparency and separation in the sound stage, increased distortion and changes in the harmonic structure of the music and ‘blackness’ of the background.

Now, do realise that in most cases, the majority of the EMI/RFI comes from the equipment itself. This is not so much the case for Audio Note equipment as they use linear power supplies with X-rated capacitors in parallel of the AC-Inlet, which largely suppress EMI/RFI noise. However some interference is still generated downstream of the AC wall socket which we have to take care of.  


Voltage Fluctuations


These are over and under-voltage events comprising prolonged periods of time that AC voltage is either too high or too low. 


The influence of real life power fluctuations on (Audio Note) audio equipment is benign. Most critical voltages of our components are (tube) regulated. The Galahad power supplies found in our higher level equipment make the components completely immune to these (and other) disturbances.


Power Disruptions


These are very common in India, and something that causes concern for many consumers owning audio equipment. 


What if the power is disrupted, and then comes back while my equipment is still switched on?


Well, first realise that most of the technology (not the engineering) on which the Audio Note equipment is based, has its roots in the middle of the last century, when the quality of the grid in the US and Europe for example, was even lower than in India today. 


Power interruptions do not damage your Audio Note equipment, as this is exactly what happens when you switch the equipment on or off.


However, there are two things we should be aware of in this context:


  • inrush currents;

  • transients.


When equipment is switched on, a relatively large amount of current is demanded from the grid, and ‘rushed’ into the equipment. So when the power comes back after a disruption, the equipment will experience this inrush. Your Audio Note equipment is build to handle this inrush, but frequent inrush currents are best avoided as they stress the components to their design limit.


When power is restored, then this is mostly accompanied with a power transient. As stated above, these are also best avoided. 


Many will argue that it is not good for the lifespan of tubes when they are frequently switched on or off. While it is true that tubes are ‘stressed’ the most while during power cycles, in practise the problem is largely mitigated by the use of ‘soft-start’ circuitry inherently present in Audio Note tube rectified and/or regulated power supplies. And again, tubes where designed and used in an era where power disruptions where much more prevalent, they can handle the stress.


From what do we need to protect our equipment?


So, to summarise, we need to protect our system (only) from:


  • Power surges and transients;

  • EMI and RFI contamination;

  • Inrush current.


And this in such a way that it will not affect the performance of our system.


How not to do that?


Installing a UPS (be it of the Standby, Online or Line-Interactive variety)


A UPS will not protect your equipment from any of the above threats. One might argue that they protect from power outages (and thus inrush currents), but in doing so they cause more harm than they prevent. Again, we only need to suppress the inrush current, the equipment switching on or off is ok. Also a UPS will not protect against surges, transients, RFI or EMI.


Some of the issues are:


  • Standby UPS’s cause transients when the power is restored, and don’t provide any of the required protections by themselves.

  • Online UPS’s are generating a lot of RFI/EMI as they are mostly equipped with inferior switched power supplies and inverters. They constantly insert unwanted noise on line, neutral and ground wires. Also they cause leakage current, something you don’t want.

  • Line Interactive UPS’s will regulate voltage (and some do in a way even regenerate AC, more on this below), but we have seen that this is not a requirement while most Line Interactive UPS's come with the same problems as online UPS’s. 


In short, UPS’s are great to keep computers and network servers online, but are best to be avoided like a plague for audio equipment.


Installing a common available surge protector


Surge protectors alone don’t protect against EMI/RFI, transients or inrush current, while 99% of all surge protectors currently available on the market use SHUNT mode technology to protect equipment. This technology uses MOV's (Metal Oxide Varistor) to conduct surge current to the neutral or ground wire.


There are many reasons why this is not a recommended method. In case of surge they are slow to react, they have a considerable lead trough voltage, will damage other connected equipment in the building and they have a limited lifetime (they WILL fail when needed).


Unfortunately you will find these MOV's everywhere, from cheap power strips to 'professional' rack mounted products.


They continuously divert transients to neutral and ground, compromising the performance of your equipment, while most likely not giving you the protection you would expect when needed.

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Installing a passive power filter


As the name implies, a power filter filters. The filters themselves do not provide any surge or current inrush protection. What they do is filter, mostly EMI/RFI, but most of them are highly in-effective in real world circumstances for the frequency range that is relevant for audio.


IF you hear an improvement using these devices, then this is most likely due to the tight clustering of output outlets. This reduces ground voltage differences, which is a good thing. This however has nothing to do with power-conditioning, but with proper grounding which is a topic in itself.


Note that Common-Mode noise can only be generated within a premises, between the N-G bond and the load in question. For system noise reduction, a simple outlet strip often works as well as, or even better, than a “power conditioner.” Filtering in most power conditioners only begins to work at frequencies above 30 kHz – at that and higher frequencies, noise no longer couples in cables like it does at lower (audio) frequencies.


As this is the case, the use of so called 'balanced' power gives very limited results (less then 10dB noise reduction in real world situation). Although it has seductive intuitive appeal, it is NOT similar to using balanced audio interfaces in any way, and can be potentially dangerous. The only technical function is to reduce leakage current, which are trivial noise sources (so easily eliminated).

Other people use power isolation transformers, but these add noise to ground trough their electrostatic shield, and have mostly unrealistic noise reduction specifications due to the high-impedance wiring and conduits in real world situations


Installing a AC regenerator


Many consider an AC regenerator as the holy grail of AC power protection and conditioning. What if there was a device which only outputs pristine, clean sinusoidal AC, at exactly the correct frequency regardless of what happens on the grid?

As we have seen above, to have a perfect 60Hz sine-wave as AC is not a requirement. AC is converted into DC inside the equipment, and properly designed power supplies can do that regardless of the amount of ‘harmonic distortion’ present in the sine wave of the incoming AC signal. 

Note that most of the ‘real estate’ inside Audio Note equipment is directly or indirectly involved with power-supply (PSU). The quality of the PSU’s in many (all) cases largely defines the performance of the component. What comes out of the PSU is essentially what we listen to. Each load requires its own specifically designed PSU however, so plugging in an AC regenerator will not transform a bad PSU to a good one. 


Again, we only need surge/transient protection, protection against external EMI/RFI and Inrush current.


Most AC regenerators don’t offer sufficient surge protection (see below) or protection against inrush current. And what they do provide, is something we don’t need for our Audio Note equipment.


AC regenerators guarantee an optimum ‘load-factor’ for equipment which have a highly fluctuating current demand. This is great for big beefy class A/B or D amplifiers, which have a low power factor. This is NOT the case however for pure class A amplifiers which Audio Note offers. 


The current draw is of our amplifiers is mostly constant, and so does not vary with the music signal (in other words, they have a high load factor). If the current is not used to feed to the speakers, it is converted into heat. That is why most of our equipment runs so hot (its the current going trough the tubes what is mostly causing the heat, not the ‘heaters’ or filaments in the tubes).


AC regenerators have become something of a trend since PS-Audio introduced some pretty (commercially) successful products. However, Paul McGowan is the first to admit that their power plants are mostly designed for amplifiers with a low power factor.


So, when you want to use AC regenerators to ‘protect’ or ‘improve’ the performance of your Audio Note equipment, you will be barking up the wrong tree at unnecessary expense.


So, what to do?


In short take the following steps in order to get the best possible power feed to your (Audio Note) system:


  1. Install a premium quality wall socket;

  2. Connect to this an Audio Note India / SurgeX SERIES mode surge protector with ISIS mains cabling;

  3. Connect this to an Audio Note ISIS (level 1-3) or SOGON (level 4 and higher) distribution block; 

  4. Connect the amplifier directly to the series mode protector, and the rest of your equipment to the distribution block using Audio Note ISIS/SOGON mains cabling.


For surge protection, the alternative to shunt mode technology found everywhere, is SERIES mode technology, which can only be found in the (patented) products of SurgeX.


These devices completely eliminate all surge/transient energy, without contaminating the ground, have a zero let through voltage (so 100% equipment protection), while they don’t deteriorate, even after many small or big surge events. So they WILL work when lightening strikes! (and will not be damaged by that)


They incorporate impedance tolerant RFI/EMI filtering. Designed, and therefore effective, with real-world power line impedances in mind, and also tolerant of any mismatch in source and load impedance. The filtering is equally effective for normal and common mode noise.


Finally these devices provide current inrush elimination, protecting your equipment against high currents during turn-on (or after power disruptions).


Audio Note India supplies a special version the SurgeX protection/conditioners, which also come with an attached Audio Note ISIS cable for optimum performance.


The standard wall-sockets and power strips in India are often of very low quality, increasing noise, ground resistance and spikes among other things. Using a quality wall socket, will eliminate these problems. The Audio Note power strips are fitted with heavily silver plated precision sockets, and don’t have noise inducing, sound deteriorating switches, fuses, lamps or other nonsense found in most power strips available in India today.


The shielded copper (or silver) pure litz ISIS or SOGON power cables, guarantee optimum current flow, very low ground resistance and their natural capacitance protect from equipment induced EMI/RFI. They come fitted with heavily silver plated precision connectors which fit snugly into our power strips.


Now, let us address shortly some main misconceptions about power cables. Many think that any short piece of cable sitting ‘at the end of’ kilometres of low quality conduit cannot make any difference for the current that ‘pours into’ the equipment. If this is your technical worldview, then your are absolute right when saying that power cables cannot make a difference.


The fact however is that, looking at it electrically, current does not pour into your equipment at all, as it alternates back-and fort 50 times per second. The power cable sits between the hot and neutral wires of the component, so from the components view, the power cable is the first component and forms part of the power supply. If you are interested in more misconceptions about power cables, then this article is a nice staring point.




Compared with many other solutions, the above presents not only the best sounding solution, it also offers the best protection against all relevant, real world threats. Next to this it's also a one of the more cost effective solutions, and should be a no brainer for the serious audiophile.

Please contact us for more information.

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