MCRU

Linear Power Supply

From £235

These days, many hi-fi separates come bundled with offboard power supplies. These are almost always small, Chinese-sourced switched mode types that are produced by the million – and very cheap due to economies of scale. They're ideal for getting low DC voltages into products like DACs, phono stages and turntable motors that have a small current consumption – for the lowest possible price.

Thing is, they generate a lot of electrical noise. Put an analogue AM radio nearby, and you can literally hear the radio frequency interference (RFI) being sprayed out. They deliver roughly the right voltage, and that's about as far as it goes. Current is low, and noise is high, but what do you expect at this price? All of which makes such things far from ideal for an audio product, especially something critical to the sound of your system like source component.

That's why there are a number of aftermarket power supplies on sale, designed to replace these so-called 'wall warts'. Let's be clear, here – DAC, phono stage and headphone stage manufacturers do not recommend their use, simply because they can't vouch for every such product on sale. As a result, using one will invariably invalidate the product's warranty – for the aforementioned reason. This is fair enough in my view, as the quality of such aftermarket devices varies enormously. Once out of warranty though, you are of course free to experiment…

I've used MCRU's Linear Power Supply with various DACs over the past decade or so, often left on for very long periods – and have had no reliability issues whatsoever. In my view, the quality is excellent at the price, with finely finished aluminium casework and top-notch plugs, sockets and leads. That's what I've come to expect of designer Nick Gorham's work, he of LongDog Audio fame. Prices start from a modest £235 for the latest version but depend on your desired application. Information can be had from the MCRU website.

The MCRU supply actually comes in two separate boxes, with the larger one housing the main power supply and the smaller case the final regulation stage. The latter is based on a low noise multi-stage filtered voltage reference, a low noise error amplifier and a high current low resistance MOSFET. It's also packed with low impedance capacitors to act as a local energy source. That's why when you turn it off, the blue power LED light stays on for a good few seconds.

The product is built to order, so will work with a wide range of equipment including all popular DACs and some phono stages; it ships with the correct DC plug, so is no harder to use than your standard, supplied PSU. You can get MCRU power supplies for Clearaudio, Pro-Ject and Rega turntables, Chord DACs, Technics SL-series turntables, Raspberry Pi computers, Mytek DACs and Auralic Aries Minis – among others. The company does different versions for different markets, including 120V models for the USA and Japan.

SOUND QUALITY

The MCRU gives a pretty clear boost to the sound of whatever you plug it into – although not quite night-and-day, it's not far off. You hear less noise, harshness, glare, hash and mush to the sound. I tried it with a classic Audiolab M-DAC among others and heard a smoother, more even and balanced performance, which made music sound less fatiguing and more enjoyable.

For example, cue up some classic electronica from Kraftwerk in the shape of Computer World, and the bass comes over tighter and cleaner, with a more open and detailed midband and a finer finessed treble. Rather than the sound being pushed out at you, the listener can peer into the soundstage and follow individual tracks more easily. There's more atmosphere and air to the recording. Similar results came from female vocals, via Randy Crawford's soulful Rainy Night in Georgia. Her singing appeared more natural and less processed, while the accompanying backing seemed to exist more in three dimensions, and have a more lilting, organic rhythmic gait.

THE VERDICT

When listening to the MCRU Linear Power Supply, I found myself quickly relaxing into its more sumptuous and expansive sound, taking it as normal and natural – and not thinking much of it. Ironically, it was only when I went back to the original 'wall wart' that I shuddered at its brittle, forward, two-dimensional presentation. This comes heartily recommended as a quick and inexpensive upgrade, then – it's a true audiophile bargain.

For more information, check out MRCU.