You wouldn’t have thought the word ‘portable’ could be contentious, would you? And I suppose it isn’t, not in absolute terms. After all, if a piece of electronic equipment (just as a ‘for instance’) is battery-powered, and can be easily lifted and moved from point ‘A’ to point ‘B’, then by definition it’s ‘portable’.
‘Portable’ as it relates to a DAC you might use to improve the sound quality of your smartphone, though, is a different matter. This EarMen TR‑Amp, for example, is a portable DAC/headphone amp that is undoubtedly capable of far more convincing and gratifying sound than any (and I mean absolutely any) smartphone is able to deliver by itself. But while its dimensions (30 × 66 × 129mm) and weight (240g) don’t suggest a device that’s difficult to transport, it’s significantly bigger and heavier than any smartphone it might accompany. Once it’s physically mated to your smartphone using its USB-C input, don’t imagine for a moment it won’t ruin the line of your jacket.
Mind you, when you consider the way the TR-Amp is specified it’s a surprise to find it’s not the size of a paperback book. At one end of the aluminium enclosure there are a pair of USB-C inputs – one is for data, the other for charging the 3700mAh battery (the TR-Amp is good for around 10 hours of use between charges), and they can be used simultaneously. There’s a pair of RCA outputs for connection into a static system, and a toggle switch to select between line-level and pre-amplified output. At the other end there’s an unnecessarily large gain control, plus 6.3mm and 3.5mm headphone outputs – these, too, can both be used at the same time.
On the inside, EarMen (a sister company to Auris Audio) has fitted the TR-Amp with TPA6120 Class AB amplifier architecture by Texas Instruments. The intention is to deliver low noise, lower distortion and sky-high on-demand current when the going gets properly dynamic. It’s also designed to allow gain-independent frequency response, so full amplifier bandwidth is available even with the volume tap fully open. EarMen reckons the TR-Amp can consistently serve up 400mW of power into 16ohms – which means there isn’t really a pair of headphones around it can’t drive comfortably.
Digital-to-analogue conversion is handled by an ESS ES9038Q2M Sabre DAC augmented by the same company’s HyperStream II Quad architecture and Time Domain Jitter Eliminator. The upshot of this flurry of exciting-sounding features is a DAC that’s ready to handle all PCM audio formats up to 32bit/384kHz resolution, MQA, and native DSD128 as well as DSD256 via DoP.
Happily, the TR-Amp makes good on that very promising specification – and it makes increasingly good as the quality of the system into which it’s implemented increases. Because for all that EarMen is happy to bang on about what an upgrade to your smartphone’s sound the TR-Amp is, the fact that it’s supplied with a shielded USB-A to USB-C cable lets you know where the company thinks this product should sit.
Nevertheless, because Hi-Fi+ is endlessly curious and rigorously thorough, the TR-Amp is tested when connected to a Sony Xperia 5 Android smartphone (via USB-C to USB-C) and an Apple MacBook Air (via USB-A to USB-C) with Shure’s excellent AONIC 50 over-ear headphones attached to the EarMen’s 3.5mm output. It’s also connected to an AVI Laboratory Series integrated amplifier (with the Sony smartphone as a source) feeding a pair of Bowers & Wilkins 607 S2 Anniversary Edition speakers, using a QED Performance Audio 40i stereo interconnect and QED XT40i speaker cable.
Admittedly a system comprising Sony Xperia 5, EarMen TR-Amp and Shure AONIC 50 isn’t really deserving of the description ‘portable’ (especially not if you’re rash enough to take the colossal Shure carry-case along for the ride), but a mobile music experience really doesn’t get any better than listening to MQA-powered TIDAL Masters – so that’s how the test begins. And there’s no denying a pass through The Divine Chord by The Avalanches [Modular Recordings] with the TR‑Amp taking care of business fairly wipes the floor with the (admittedly wirelessly provided) sound the Sony is capable of handing over to the Shures by itself.
Once you’re over the initial shock and awe of just how straightforwardly loud the EarMen is, it’s possible to revel in the absolute solidity of its soundstage and the prodigious amount of detail it retrieves. Low frequencies are burly and controlled, with ample extension and completely straight-edged positivity. High frequencies shine benignly, with the substance to balance their brightness. And in between, the MGMT vocal is balanced nicely – there’s enough low-level harmonic variance to give proper expression to voices, even if (as here) they’re scrapping for primacy in a fairly busy mix.
Introducing the TR-Amp into a desktop system bring, if anything, even more tangible improvements. A 24bit/192kHz FLAC file of The Band’s Jawbone [Capitol], delivered by Colibri to bypass Apple’s abiding disdain for the FLAC format, enjoys unshakeable rhythmic expression and a stack of dynamic headroom. The timing of the EarMen is such an improvement over that of the DAC sitting behind a MacBook Air’s headphone socket that it’s almost comical.
Incorporating the TR-Amp into a full-size system is a slightly more qualified success. Certainly it allows the Sony smartphone to sound considerably bigger and better-realised then when it’s wirelessly connected via a Bluetooth DAC such as AudioQuest’s Beetle. But it rather undermines the point of linking a smartphone to a full-on amplifier in the first place: the smartphone needs hard-wiring to the TR-Amp, and consequently a complete lack of convenience is revealed the moment you wish to (for instance) skip a track.
The TR-Amp has a functionality sweet-spot, and it’s not as part of a full-on audio system any more than it is as an aid to your truly portable listening. No, where the EarMan makes perfect sense is as part of a desktop system. If you want to listen to headphones while sitting in front of a computer – ideally a computer holding some nice fat high-resolution audio files – it’s nigh-on perfect.
TECHNICAL SPECIFICATIONS
- Type: Solid-state digital-to-analogue converter and headphone amp
- DAC resolution/supported digital formats: All PCM from 44.1KS/s to 384KS/s with word lengths up to 32‑bit, DSD128 and DSD256 via DoP
- Distortion (THD + Noise): < 0.005%
- Inputs: USB-C (data); USB-C (charging)
- Outputs: 6.3mm stereo; 3.5mm stereo
- Dimensions (hwd, mm): 30 × 66 × 129
- Weight (g): 240
- Price: £269
Manufacturer: Earmen
URL: earmen-eu.com
UK Distributor: SCV Distribution
Tel: +44(0)330 122 2500
By Simon Lucas
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