Disclaimer: Earmen is the portable device wing of Auris, the famous tube amplifier maker out of Serbia. I own and enjoy the Auris Euterpe and have had the privilege of trying several other Auris amplifiers and can say all have been outstanding. For that reason when I was approached about reviewing the new line of Earmen products I couldn’t say yes fast enough. I will admit to high expectations coming into this due to my previous experience with their parent brand. I was provided the unit for review, but have received no compensation otherwise and have no financial interest in either Earmen or Auris. I was given no instruction on things to include or edit for this review. For more information on the TR-Amp, See the Auris/Earmen website.
The TR-amp ships in a black lift-top style box with a line drawing of the amp on the front and the particulars on the reverse. Inside the package you’ll find the amp, a carry case, a rubber band for attaching a phone or dap, and a USB-A to USB-C cable for attaching to power or PC. A small printed instruction sheet rounds out the package. It would be nice to see a USB-C to USB-C interconnect included in the package or at least a short cable to pair with an OTG adapter as the primary role of the TR is as a portable device and many will want to pair to a smart phone. Otherwise the kit is fairly complete.
The TR-amp uses a cnc milled anodized aluminum housing with the end plated screwed solidly on at both ends. The volume dial is brushed aluminum as well giving the unit a very solid feel and little or no plastic anywhere in the build. On the front the TR has a 6.3mm jack, a 3.5mm jack (and they do advertise the ability to drive both simultaneously), and the volume knob. On the rear, two USB type C ports (one for data, the other power) are followed by a pre-out/direct switch, and a pair of RCA outputs. The sides and top are clean while the bottom sports 4 rubber feet to protect the unit. The unit feels very solid in hand with nothing rattling, shifting, moving etc. Controls are very positive and the volume knob adjusts smoothly without feeling too light or too stiff. The unit is not much larger than a deck of cards, or for a non-PC example a pack of 100’s cigarettes.
Inside the TR-amp we have a 3700 mAh battery powering the operation with separate usb-c inputs for data and power. The usb input uses the xmos driver for windows to allow for up to 32/384kHz PCM, DSD128, and MQA rendering. An ESS 9038q2m 2 channel DAC chip handling the D/A conversion. The ESS chipset also incorporates time domain jitter correction as well. Amplification duties fall to the Texas instruments TPA6120 op-amp. This is a bit different style op-amp than most as it is a current-feedback design. When compared to more common op-amps, this design is said to provide higher bandwidth, lower noise, and improved dynamic range. This provides up to 400mW into 16Ω so the TR should be capable of driving all but the most demanding of cans. An analog volume control is provided for pre-amp or headphone amplifier duties. In addition, the TR-amp uses low ESR tantal capacitors in the power supply side to reduce noise introduced by the power supply. A 3700mAh battery provides a listed 10 hours of battery life. I found 8 to be a more realistic number in actual use, but this is still very reasonable for devices in this class.
PCM support is up to 32bit/384kHz while DSD is supported natively up to 128 and software decoded up DSD256. The TR is also an officially licensed MQA product meaning it supports a full native MQA hardware renderer. This is becoming more common, but is still not seen as often as PCM and DSD support. The Addition of MQA means the TR supports Tidal Masters at full resolution. I’ve heard arguments both for and against MQA with proponents claiming greatly improved sound and opponents claiming it is more about file size for streaming services than audio quality for the end user. I think the answer lies somewhere between the two extremes as MQA does provide a way to package high quality audio into smaller files than FLAC and may ultimately lend itself to better quality depending on the encoding process. If you have an interest in MQA, you can learn more about it here.
I have to admit, I read the specs and immediately had expectations of what the TR would sound like. The ESS Dacs are well renowned for a slightly cool signature with an analytical lean to them. That is what I was expecting when I powered on the TR and I was partially right. The TR does have great detail levels and clarity but instead of being as cool as expected it is nearly neutral. Linearity is fantastic with no major humps or dips anywhere throughout the range. The feature I didn’t expect (and maybe I should have from Auris) is the musicality presented by the TR. Bass has impressive weight and good body without getting boosted. Speed of both attack and decay are good but at moments the bass sacrifices some precision for musicality so it may come off as just slightly lose. (Don’t get me wrong at the price point it is better than one should reasonably expect). The transition between bass and mids is clean and the mids are well voiced and again extremely well textured and detailed. Treble continues the trend and again is clear, well detailed, and extended without being forward of the rest of the mix. Layering is better than average with no tendency to thicken, but that soft edge mentioned earlier keeps the TR from sounding clinical or sterile and makes it good long session experience without fatigue. Stage has good dimensions as well although this tends to be defined more by the headphone in use than the amp behind it. At the least I can say the TR does nothing to detract from things like the HD800 that is known for its stage size.
As mentioned earlier, the TR puts out 400mW @ 16Ω which puts it in the middle of the portable market power wise. It was able to handle most of my collection and the things that made it stumble were not unexpected. No , it won’t power the He6 well, and even the He560 could use more power than the TR is able to pump out. On the other hand, the Ananda runs beautifully paired to the TR and the clarity of the TR really allows the resolution of the Ananda to be put on full display. It worked equally well when paired to the LCD2 Classic so planars in general are not an issue, just really low sensitivity planars. I tested using the HD700 and HD800 Sennheiser models as well as the Campfire Cascade and Focal Elex in the way of dynamic drivers.
Iems are a bit more mixed when paired to the TR as the noise floor is a bit high for ultra-sensitive iems like the Magaosi K5 which is renowned for hiss. Lower sensitivity or higher impedance both help to reduce hiss and with most iems that are below 104 dB/mW or so or over 32Ω have little issue at all with hiss. Its fairly obvious the TR was designed with full sized cans in mind, but it works well with most iems and even things like the magaosi can be tamed with something like the ie-match.
ifi Micro iDSD – These two have similar shapes with the ifi being roughly twice the length of the TR but similar in shape and all other dimensions. I much prefer the Type C USB inputs on the TR when compared to the Type A used on the ifi as male to female usb cables have always been a specialty item and this limits options. The anodizing on the TR gives it a premium look when compared to the brushed aluminum of the ifi. Build quality on both is very good so it is difficult to find fault with either in that respect. I do like the fact that TR leaves the screws exposed and makes it easy for the end user to change batteries if need be as the ifi is a no-user serviceable parts design that takes a good bit to get into if replacing the battery. Both sport roughly the same battery life, so there again no clear winner between the two.
The ifi has adjustable power output with 4 levels while the TR is a fixed output that most closely matches the high output setting on the ifi. To my ear when used for the DAC alone and fed into an external amplifier, the TR is a bit cleaner and more detailed. What really stands out to me is the musicality of the TR when compared side by side with the iDSD. The iDSD comes across as a bit sterile by comparison and simply lacks the weight that the TR provides. I never thought of the ifi as thin sounding, but beside the TR it definitely is the leaner of the two.
Xduoo XD-05+ – Again, similar shapes and similar niche for these two. The XD is slightly longer and wider but thinner when placed side by side. both can be opened easily as well as the XD is designed for interchanging op-amps, and both sport a metal shell for durability. The TR looks and feels a bit more solid in the hand while the XD offers a display screen and exposes the filters of the dac so more adjustments to the sound are possible. The XD also offers Optical and Coax inputs so is a bit more flexible compared to the TR. Where the TR wins is again on the strength of its sound and musicality. While op-amp rolling allows for tuning of the XD, I have yet to find a combination even with boutique op-amps that I feel is as musical or enjoyable as the TR is out of the box.
While the market is full of portable DAC/Amps and I own more than a few, I am still surprised by the Earmen TR-amp. Perhaps I shouldn’t be, Auris has proved to be quite capable in designing sophisticated tube amps but with this being solid state and portable, it is certainly a horse of a different color and with it being a first product in the stable, some foibles seem understandable. While the TR is limited to only USB input it does a good job handling that well and offers both a pre-amp with volume control for use with powered speakers, a pure dac mode for use with an external amp, and two headphone outputs. Its tuning is both linear and detailed and musical at the same time. Admittedly, it trades the last bit of detail for weight and musicality, but that is a sin that is certainly forgivable. I can see many using the TR as a desktop DAC/Amp to pair with their laptop, and others being happy with it in a more portable role tethered to a phone. Either way the TR seems equally at home and does a great job with a wide variety of headphones. I did find that it struggles with headphones or earphones at both extremes in sensitivity but it thrives in the middle ground where most every day headphones are found. This is a very mature product for a first effort and one can only imagine what is coming next. I’m looking forward to it.
Pros – build quality, musicality, battery life, MQA format support
Cons – USB only, some hiss with super sensitive IEMs, middle of the pack power.