Sounds emerging from smart devices need help if they're to feed superior headphones. If you've invested in aftermarket on-, over- or in-ear cans with aspirations to audiophile credibility, you'll learn these need both power and sound quality that simply aren't available from portable devices. WIRED has chosen five amps, ranging from £520 to £6,000. Each has been designed primarily for use with headphones, as opposed to being a full-function DAC or pre-amplifier intended to drive a hi-fi system - but doing double-duty can be a feature. All have one common goal: to take headphone audio to the next level.
Read more: The best headphones for any budget in 2021
Rocking the old-school exposed valves, the QUAD PA-One is a headphone amp that also packs in a full-function pre-amplifier and DAC from one of the UK's most revered audio brands. This means it can serve as the heart of a full system, with the addition of an amp and speakers such as QUAD's compact S-1. The most self-contained of the units, its all-valve topology produces a rich sound for vinyl fans (be warned - it doesn't include a phono stage). It easily drove all three headphones, sounding particularly good with Audeze LCD-X.
Score: 8/10Cost: £1,199Usability: Versatile and user friendly. It is able to drive two sets of headphones via 6.35mm sockets Settings: A choice of high or low impedance. Balanced XLR and RCA single-ended. Coaxial, optical and USB inputs Dimensions: 180mm x 284.5mm x 163.5mm (requires desk space) Design: Lancaster grey colour scheme with an attractive matt finish
Pro-Ject is the world's largest turntable manufacturer and a specialist in affordable electronics. The best buy in our round-up, the Head Box DS2 B drives both conventional and balanced headphones. The buttons on the right provide three different current settings to match any headphone type, as well as four gain settings for high-impedance headphones or sensitive in-ear monitors. The device accepts a balanced and a single-ended source, and also has a bypass output, enabling it to feed a recorder or preamp. Sound is punchy, detailed and surprisingly gutsy - a head-banger's delight.
Score: 7/10Cost: £520Usability: Four gain settings for perfect level adjustments Settings: Three current levels to match any headphones Dimensions: 206mm x 71mm x 218mm Design: Wooden side-panels in silver/walnut or black/eucalyptus
****: All the headphone amplifiers on test were auditioned with music from an iMac using Fidelia, iTunes and Audirvana, and CDs via the Pro-Ject CD Box DS CD player, either line-out or digital output when appropriate.
Headphones included the 20-ohm Audeze LCD-X (£1,499) as an example of a high-end, open-back, planar-type purist model; the 32-ohm Master & Dynamic MW60 for a semi-open-back model; and the 32-ohm Focal Spirit Classic (£239) for a sealed-back type. Most modern headphones fall into the low-impedance category, so it's unlikely that there are many sets these amps won't drive.
One for hardcore tube purists, but with a twist: although the Unison Research SH is a Single-Ended Class A all-valve design, it has a USB input for a feed from digital sources. This is asynchronous, compliant to USB 2.0 Audio Class, and accepts PCM up to 384kHz and DSD up to 128x. That said, the SH is minimalist and can drive two sets of headphones. Tech spec aside, the sound is pleasingly warm and "analogue-y".
Score: 8/10Cost: £1,250Usability: Simple controls. Designed to be used with traditional analogue sources and computers Settings: High or low sensitivity options. Supports 32-bit resolution Dimensions: 225mm x 126mm x 322mm Design: Striking finish in either black or cherry wood. Wood trim on remote control matches corresponding hi-fi component
Coming from a maker of amplifiers and speakers that look like alien spacecraft, the Marquis Memento Mori is a line-level analogue preamp that accepts two line-level sources, such as a CD player, and can drive a separate amp. The front features a 6.35mm headphone socket flanked by the source selector and volume control. The skull is made from CNC-machined, anodised aluminium and is available in ten colours, making it as much a talking point as it is for listening. Sound is silky-smooth and detailed, with plenty of power for difficult headphone loads. The unit can be optimised for a specific set of headphones.
Score: 9/10Cost: £6,000Usability: Easy. Just connect source and mains cable; can also serve as a pre-amp Settings: Accommodates one set of headphones via professional connector Dimensions: 150mm diameter Design: The skull's illuminated eyes serve as power meters. A pair of red dials sit beneath the cheekbones for volume and input selection, and the headphone socket can be found in the skull's mouth
Fully Balanced Headphone Amplifier With build quality and finish that belie its relatively low price, the MX-HPA is the dream entry-level model for those who own fully balanced headphones and sources. This is a more recent phenomenon for cans, applicable mainly to high-end models, and is still obscure enough to be filed under "Who cares?" - the vast majority of headphones use a single stereo jack. Musical Fidelity's unit provides a balanced input as well as a normal RCA phono input; its panel allows use of two sets of normal headphones or a balanced set with an adaptor. The unit easily coped with WIRED's test pairs, with audio sounding rich and especially appealing for bass fiends.
Score: 7/10Cost: £769Usability: Balanced operation for input and headphones for superior sound Settings: There are two gain positions available to accommodate both high- and low-sensitivity headphones Dimensions: The most compact unit on test, at 220mm x 53mm x 240mm. This is a good choice if space is at a premium Design: Superb construction and luxurious feel
Read more: The best wireless headphones for audio without aggravation
This article was originally published by WIRED UK
