This diminutive, studio‑oriented desktop amp can drive nearfield speakers or multiple pairs of headphones with equal aplomb.

Based in Kent, England, Chord Electronics are perhaps best known as manufacturers of high‑end hi‑fi gear. But they started out in the studio market, and retain a strong presence in its upper echelons. Control rooms all over the world rely on Chord power amplifiers to drive everything from huge main monitors to Auratones and NS10s, and at this year’s NAMM Show, the company announced what is probably the most SOS‑friendly product they’ve ever made. Offering an innovative and, as far as I’m aware, unique combination of features, the Alto is a miniature power amplifier and headphone amp designed specifically for studio use.

Now that most nearfield monitors have amplification built in, this is a relatively underpopulated product category. So if, like me, you still cling stubbornly to the idea that NS10s are a valuable tool in the 21st Century, you’ll know how hard it can be to find a suitable amp to drive them. Over the last decade or so, I’ve been through several second‑hand amps, all of which eventually fried themselves. I’ve bought a budget rackmount model which delivered almost as much fan noise as it did power into 8Ω. And I’ve baulked at the idea of dragging a huge Bryston or similar into my fairly modest room just to power a secondary pair of monitors.

So, on paper, the Chord Alto looks like the perfect product for people in my position. It’s small: 1U high with the optional feet removed, and about 21cm square. It’s fanless. It delivers 50W into 4Ω, so is clearly intended for nearfield monitoring applications. Unlike most hi‑fi gear, it has XLR inputs as well as RCA phonos. And, as we’ll see, it’s much, much more than just a power amplifier.

Altoed Images

The Alto isn’t quite as exotic in appearance as some of Chord’s hi‑fi kit, but has clearly been designed by someone with a keen aesthetic sense. It’s made in Britain, and is every bit as well built as you’d expect at the price, with an impressively tough and smart aluminium shell. The rear panel boasts stereo inputs on XLRs and RCA phonos, speaker outputs on banana sockets, and a pair of line‑level outputs on male XLRs. Maximum input level is specified as 6V RMS, which equates to +18dBu. The Alto takes 12V DC from a large laptop‑style PSU, connected via a four‑pin locking connector, and power can be cascaded to other Chord devices courtesy of an adjacent 12V output.

The front panel is eye‑catching, to say the least, with visual feedback presented on three large glowing marble‑like buttons. The largest of these even rotates in a satisfying way when you roll your thumb across it, although it’s actually just an on/off switch. It’s flanked by input and output selector buttons which light up in different colours to tell you which ins and outs are in use. Either side of these, there’s a single volume control and no fewer than four headphone sockets: two quarter‑inch jacks, a mini‑jack and a 4.4mm Pentaconn ‘balanced’ output. A fourth ‘marble’ is neither a control nor an LED, but a window for the included infrared remote control.

The remote too is surprisingly and impressively well built, with a sleek and rigid metal case. It has many more buttons than there are controls on the Alto, so is presumably designed to work across the entire Chord range. Chord even have the forethought to include the two AAA batteries you’ll need to power it, though not the tiny crosshead screwdriver you’ll need to open the battery compartment! Point the remote at the device and hit the volume up or down buttons and you’ll witness the Alto’s party trick: its volume control is motorised, so whether you adjust it by hand or remotely, there’s never a discrepancy between the position of the control and the actual volume setting.

The Chord Ultimatum

At the core of Chord’s power amplifiers is a technology called Ultima, developed by company founder and design guru John Franks. There are several elements to this, starting with their own high‑frequency switch‑mode power supply, but the key technical feature is something called “dual feed‑forward error correction”, whereby the amplified signal is continuously compared with the input signal and adjusted as necessary. The Ultima design uses Chord’s proprietary MOSFETs, operating in Class A/B, giving the Alto a significant point of difference compared with most small desktop amps, which these days are usually Class D. It also delivers specifications that rival high‑end Class‑D amps. THD, for example, is quoted as 0.003% into 4Ω, which is a couple of orders of magnitude better than a typical traditional rackmounting amp, and signal‑to‑noise ratio is an impressive 119.6dB.

The Alto’s form factor makes it look a lot like a monitor controller, and it has a little of the functionality you’d expect from such a thing — but if you expect it to be a monitor controller, you’re likely to wind up scratching your head. For example, on a typical monitor controller, you’d expect the headphone sockets to have their own amps with individual level controls. That’s not the case here. The point of the Alto is to provide a single, really good stereo amp, with switching that allows this to be fed either to the speaker outputs, or simultaneously to all four headphone sockets. It’s not possible to have both the speakers and headphones active at once, or to adjust their levels independently. By contrast, the line‑level XLR outputs can optionally be made active at the same time as either the speakers or the headphones; they can also be exempted from the Alto’s volume control in order to feed another amp, master recorder, meter or monitor controller further down the line.Alto_02

Having everything be subject to a single volume control can certainly prove frustrating if you try to treat the Alto as your main monitor controller. The setting that gave me a comfortable level from my NS10s was much too loud with most of the headphones I tried, so it isn’t really feasible to toggle rapidly back and forth between speakers and cans for checking mixes and so on. Nor is the volume control detented, so you can’t easily restore a previous setting. And although there is a Dim button on the remote, this merely makes the LEDs less bright! In long‑term use, you will probably end up employing the Alto either as a headphone amp or as a speaker amp, depending on what you happen to be doing that day.

The Alto sounded better than anything else I personally have ever connected to my NS10s, and it wasn’t subtle.

Power Trip

The flip side of this is that standard monitor controllers aren’t power amps, and thus can’t drive your NS10s, Auratones, LS3/5as and so on. The Alto not only can do so, but does so spectacularly well. Power amplifiers are not the easiest thing to A/B, but the Alto sounded better than anything else I personally have ever connected to my NS10s, and it wasn’t subtle. The few other studio‑oriented power amps on the market aimed at nearfield listening typically offer at least 100W per channel into 8Ω, so the Alto’s 50W into 4Ω might sound underpowered, but that wasn’t at all my experience in practice. Even though it presumably develops only 25W or so per channel into an 8Ω speaker like the NS10, it delivers all the level I personally would ever want, and a fair bit more besides. Unless you’re the kind of mix engineer who blows through a new tweeter every week, I think it would be more than adequate for nearfield listening in most environments.

If anything, the Alto’s prowess as a headphone amp is even more impressive. With its four outputs all operating at the same level, it’s not the most flexible headphone amp, but boy, does it sound good. As you’d expect, given that it can deliver a specified 2.25W into 100Ω, it has no trouble driving the most awkward of loads. I expected it to sound great with high‑end open‑backed headphones and it didn’t disappoint. What really surprised me, though, was the difference it made with relatively modest headphones. Plug the same set of cans into the built‑in headphone amp on even a high‑end interface, and they sound flat and lifeless by comparison with the Alto, which delivers a lot more punch and dynamic impact.

It might, of course, seem a bit perverse to pay several grand for an amplifier to power speakers or headphones that are probably worth a tenth of that. But it’s the system as a whole that matters. Most guitarists would be much happier playing a Squier through a handwired Fender Deluxe than they would playing a Custom Shop Strat through a cheap practice amp, and although I don’t think the analogy always holds for studio monitoring, the Alto will certainly bring out the best in whatever transducer you choose — whether that’s a humble pair of passive speakers or a set of headphones that cost more than your car.