This is Volume 2ii of FutureShop's comprehensive guide to hi-fi cables and accessories, covering power distribution blocks and power conditioners. Browse our full power distribution range or contact our team for advice tailored to your system.
About This Guide
Power distribution blocks and power conditioners sit at the beginning of your hi-fi system's power chain, before any cable or component. Getting this right is not complicated, but it requires understanding two things: the difference between distribution and conditioning, and which of your components need clean filtered power versus unrestricted current. This guide covers both in plain terms, with a practical selector table at the end to help you match the right solution to your system.
Quick Take: What This Guide Covers
- Distribution blocks: series vs star-wired circuits, and why wiring topology matters as much as socket count
- Power conditioners: how filtering works, why power amplifiers and subwoofers require special consideration, and what "linear" filtering means in practice
- Earth noise: why good conditioners drain it away, and why pairing a conditioner with the same brand's power cables is worth considering
- The practical selector: which solution fits which system, mapped to FutureShop's range
Vol. 2ii: Power Distribution Blocks and Conditioners
It's now time to look at power distribution blocks and power conditioners. Distribution blocks are designed to extend one mains outlet into multiple, and higher-end versions will have features like filtering or isolated sections. Power conditioners are purpose-built mains filters, designed to eradicate 'noise' from the electrical supply, and will also usually have multiple outputs.
Power Distribution Blocks
Let's start with the more entry-level option: distribution blocks. The most basic options will simply allow multiple plugs to connect to one mains outlet, but will have their internal circuit wired in series. If you cast your mind back to primary school science lessons, you will probably remember a day when your teacher set up a basic circuit with a battery and a few small lightbulbs. When arranged in series, the lightbulbs would get dimmer as more bulbs were added to the circuit because the current only has one path to travel down. A distribution block internally wired in series will have a similar effect, which means that multiple high-powered units plugged into one distribution block may struggle to receive sufficient amounts of current.
For that reason, better distribution blocks designed for HiFi and AV uses will feature star-wired circuits (similar to what we would have called parallel circuits in primary school). In this case, the current always has multiple routes to take and such a distribution block can simply take more current from the mains to ensure that each component receives enough power. To improve upon this, some distribution blocks will implement multiple star-wired circuits within the block. This has the added effect of creating multiple zones which provide a degree of isolation, allowing you to separate your noisier hardware from more sensitive equipment.
When selecting a power distribution block, it is important to ensure that it is of a similar standard to your equipment. Higher-quality power blocks will utilise lower-gauge (thicker) conductors, which is particularly important for high-current components such as power amplifiers. A block with undersized internal wiring will restrict the current available to a demanding amplifier during loud or dynamic passages, compressing the sound in a way that is difficult to diagnose but easy to hear once you know what to listen for. This is one reason why the internal wiring of a distribution block is as important as its external connections, and why the brands we stock at FutureShop, including the Chord Company PowerHAUS range and IsoTek, specify their internal conductor gauge as part of their technical documentation.
Power Conditioners
Power conditioners are devices which are specifically designed to filter 'noise' out of your mains power supply. There's a variety of different ways that such units actually filter that power, but we're not going to delve too deeply into the electrical engineering elements of those differences. Our focus here is more on how to choose a power conditioner to meet your needs.
Firstly, it's important to note that there can be such a thing as too much filtering. Some manufacturers of power amplifiers or subwoofers will advise against placing any kind of filter between their unit and the mains. This is because a power amplifier or subwoofer is not only a greedy component, but the amount of power it demands can vary greatly over the course of a song. This means it needs a low-impedance path from the power source, and the ability to rapidly increase its demands. For that reason, some power conditioners could have a detrimental effect on the performance of power amplifiers/subwoofers by essentially choking that supply, resulting in a loss of dynamism and leaving your music sound a little flat or subdued. That does not mean, though, that you can never plug a power amp or subwoofer into a power conditioner.
There are some manufacturers who have taken this into consideration by providing high-current outlets on their conditioners, and there are a couple of ways they can deal with the demands of hungry power amplifiers. The simpler option found on more entry-level options is to simply provide high-current outlets which do not filter the power, allowing the high-current component to draw its supply directly from the mains. In higher-end options, where the high-current outputs are being filtered to some degree, there will often be a component which provides a power reserve for your amplifier or other high-current components to ensure that they are never left wanting.
This is not a concern for constant-current devices, like streamers, CD players, turntables or DACs. Once such components are switched on and operational, they use a consistent and lower voltage, and as such are not in danger of being choked by excessive filtering. Constant-current devices will invariably benefit from a supply of low-noise current which will allow them to perform to their full potential.
What is important for a conditioner, regardless of the equipment you are looking to plug into it, is that it filters power in a 'linear' way. When we talk about 'linear' power filtration, we mean the result of the filtering more so than the process itself. 'Linear' filtering means that all the frequencies being output by the conditioner are consistent, which results in dynamic and natural sound. A 'non-linear' filter will deliver different frequencies with varying consistency, meaning that some frequencies will end up sounding muffled or harsher than the rest of the music.
It is also worth considering the way your power conditioner deals with earth noise. Good power conditioners will drain this noise away from the unit and back to the mains or a grounding box (not usually included) to stop it interfering with your system. In the case of a conditioner that does perform this, you would likely benefit from using power cables from the same manufacturer, because their wiring will complement what the conditioner itself is doing to deal with ground noise.
Ultimately, there isn't necessarily a singular 'best' power conditioner, there is only the right one for your system and its needs. Do you have lots of power-hungry, variable-current equipment, or more sensitive constant-current equipment? Do you have a particularly noisy mains supply, and want to filter the power for even your hungriest components? Questions like these will be what informs each individual's decision, and one blog post cannot categorically answer them. As always, for advice tailored to your system, we would recommend getting in touch with our expert technical advisers who are always ready to steer you in the right direction.
Power Solution Selector: Matching Your System to the Right Approach
The guide above explains the principles. This table applies them to the four most common system scenarios we encounter at FutureShop, linking to the relevant part of our range for each.
| Your system | What to prioritise | What to avoid | Starting point |
|---|---|---|---|
| Constant-current components only: streamer, DAC, CD player, turntable, phono stage. | A star-wired distribution block with good internal wiring and multiple isolated zones, or a filtered conditioner. These components benefit most from low-noise power and are not at risk of being choked. | Entry-level series-wired blocks with no zone isolation. | IsoTek V5 Polaris or Aquarius; Chord PowerHAUS P6 |
| Mixed system: integrated or power amplifier alongside source components. | A block or conditioner with dedicated high-current outlets for the amplifier and filtered outlets for sources. Zone isolation between the two is the key feature to look for. | A conditioner that applies heavy filtering to all outlets equally, with no high-current provision. | IsoTek V5 Corvus; Chord PowerHAUS S6 or M6 |
| Noisy mains supply. Audible hum, interference, or degraded performance at certain times of day. | A conditioner with strong linear filtering across all outlets, and good earth noise drainage. Using power cables from the same manufacturer as the conditioner maximises the benefit. | An unfiltered distribution block, which extends the noise to more components rather than addressing it. | IsoTek V5 Sigmas; Shunyata Hydra Delta D6 |
| High-end system. Power is already clean. Priority is minimal interference with the signal rather than heavy filtering. | A passive, unfiltered distribution block with star wiring, heavy-gauge internal conductors, and zero added components in the circuit path. The goal is transparency rather than treatment. | A conditioner with aggressive filtering, which can compress dynamics on a system that does not need it. | Chord PowerHAUS M6; AudioQuest Niagara |
If your system does not fit cleanly into one of these categories, or if you are unsure whether your mains supply is a problem worth addressing, our team can discuss your setup in detail. A five-minute conversation about your components, your room, and what you are hearing is usually enough to give a clear recommendation.
For a close look at how a high-quality passive distribution block performs in practice on a reference system, our Chord PowerHAUS S6 review covers the ARAY-equipped block alongside the Ayre and B&W 800 series reference system. And when you are ready to move on to speaker cables, Vol. 3 of this guide covers every variable in speaker cable selection in the same format.
FutureShop stocks power distribution blocks and conditioners from IsoTek, Chord Company, Shunyata Research, AudioQuest, and more. Browse the full range, or get in touch with our team at 0800 772 3688 or 0208 905 1555 for free expert advice on the right solution for your system.
