Fiio Q1 Mark II review Reddit

I have been writing about audio professionally since 1989. In that time, I have conducted more brand-concealed listening tests than any other audio journalist in North America (and probably the whole world) while evaluating a few thousand speakers, amplifiers, and other types of audio equipment. I’ve worked as a staff editor or contributing editor for many audio publications, including Sound & Vision, Home Theater Magazine, SoundStage, and AudioXpress. I am a member of the Audio Engineering Society, and I own a full suite of lab measurement gear for testing audio products.

Senior staff writer Lauren Dragan wrote previous versions of this guide and assisted in the listening tests and product evaluations for this one. Lauren earned a bachelor’s degree in both music performance and audio production, and she spent several years in and out of top recording studios as a radio engineer and voice actor. In addition to the more than 1,500 headphones and audio accessories she has reviewed for Wirecutter, Lauren has also reviewed high-end home audio equipment for publications such as Home Entertainment, Home Theater Magazine, and Sound & Vision, and she has written about audio for such publications as Fast Company, Forbes, the Los Angeles Times, and Time.

A previous testing panel also included John Higgins (Lauren’s spouse), a professional musician, composer, audio mixer, and Wirecutter contributor who has a master’s degree in music from the University of Southern California and a bachelor’s degree in music and audio recording from Ithaca College.

Wireless headphones and earphones can deliver very good sound quality, but they don’t produce the best sound quality because of the losses due to Bluetooth compression and the compromises required to pack so much technology into a tiny space. Wired headphones generally deliver better sound for the money, yet many new smartphones do not include a headphone jack—and some audiophile-oriented wired headphones require more power to drive them to satisfying volume levels than mobile devices and computers can muster. You can address both of these issues by using a portable headphone amp/DAC that can connect to the audio device’s digital output—generally, a USB-A connector on computers, a Lightning connector on Apple iOS phones, a USB-C connector on new Android phones, or a USB-B micro connector on older Android devices.

Inexpensive dongle-type amp/DACs (like this Lightning adapter) are available at low cost, and for most headphones, one of these will work fine. But it may not have enough power to drive headphones with a higher impedance (which is specified in ohms and defines how much resistance the headphones have to the flow of electrical current) or a lower sensitivity (which is specified in decibels and defines how loud the headphones play with a given amount of power). You can read more about headphone impedance and sensitivity on Shure’s website. If you own or are considering purchasing headphones that have an impedance of 100 ohms or more or a sensitivity rating below 98 dB, a cheap amp/DAC dongle may not have enough power to drive them to sufficient volume levels.

The same is true for the headphone amps built into phones, tablets, and laptops, which is why headphone enthusiasts tend to add a portable amp/DAC when listening to music from their mobile devices.

There’s one more possible reason to use a portable headphone amp/DAC: Many high-end, audiophile-oriented earphones use balanced-armature drivers, whose impedance rises greatly at high frequencies of sound. An amplifier that has high output impedance interacts with the earphones’ own impedance to change the sound, usually making the result somewhat dull and boomy. (You can read more about output impedance in the next section.) Even most cheap headphone amps have low-enough output impedance that this isn’t a problem. However, the output-impedance spec is almost never published, and few review sites (Wirecutter excepted) measure it, so there’s rarely any way to know for sure.

What about the DAC part of the equation? Marketing materials for these amp/DAC models often promise that their digital-to-analog converters sound better than those built into phones and computers. However, we’ve never seen these claims substantiated in independent, controlled testing. In our own tests, in which we do everything we can to eliminate bias and compare all of the contenders fairly, we’ve heard extremely tiny, and musically insignificant, differences among these models.

Lauren likened the experience of comparing amp/DACs to tasting two batches of muffins: Say one batch has 1/16 teaspoon more salt in it than the other. Can you taste the difference between muffins from each batch? Maybe, but even if you can, it’s unlikely to make or break a batch of muffins, and there’s no way to know which batch a certain taster will prefer. Also, there are a lot of other factors that have far greater effects on the muffins’ flavor.

• Audiophile headphones focus on delivering the best sound quality, period. We’ve tested hundreds of them and selected our favorites for specific uses.

Here are the criteria we developed to determine which headphone amps to call in and test, as well as which ones should ultimately become our picks:

• The price of a portable headphone amp shouldn’t be more than that of the headphones you are using. Additionally, since you use these devices on the go, we set a $400 upper price limit. The average audio fan might hesitate to take their amp traveling with them if they paid more than that.
• Portability and convenience are key. If a portable headphone amp is heavy or a pain to lug around, you won’t want to use it. We sought options that could easily fit in a laptop bag or a pocket. We considered both USB- and battery-powered amps. Models that draw power via USB are generally smaller and more portable than those with a built-in battery, but because they take their power from your audio device, they drain the device’s battery (though our tests show this drain to be minimal). A battery-powered portable amp should last at least a full workday per charge, and most of them do.
• Connections are, for the most part, limited to USB. Many are shaped like USB memory sticks, with an integrated male USB-A plug. Others have a female USB-C jack. We preferred amps that come with adapters that let them work with USB-A or USB-C sources; generally, iOS users have to purchase separate adapters.
• Ease of use is important. You shouldn’t need to fiddle with frustrating software to start listening. The buttons and ports should make sense. A brief initial setup process is fine, but after that, a good amp/DAC combo should be pretty plug-and-play.
• As for amplifier power, we wanted a headphone amp that had a measured output of at least 15 milliwatts for 32-ohm headphones, which should be more than enough power for most people to listen at a sufficiently loud volume level.
• Sound quality is obviously a factor. An external headphone amp/DAC shouldn’t make headphones sound worse than the one included in your computer or mobile device. Ideally, the sound would be measurably or very noticeably better, but as our testing found, that isn’t always the case.
• Output impedance is effectively a measure of how much an amplifier might affect the sound of a headphone. Every headphone is essentially an electrical filter, with resistance, capacitance, and inductance that affect the sound differently as the frequency changes. Adding impedance (or resistance) can change the values of the filter and thus change the sound of a headphone in ways that can be difficult to predict. Put simply, the lower the amplifier’s output impedance, the better; 0.1 to 5 ohms is ideal. Output impedance is rarely published on headphone-amp spec sheets, so we tested for it on our finalists. Although most dynamic headphones are relatively immune to the potentially negative effects of a higher output impedance, a few aren’t—and in-ear headphones with balanced-armature drivers can sound very different when paired with a headphone amp that has high output impedance, such as the generic, cheap headphone amps built into laptops. (To make sure we caught any issues, we used a variety of headphones in our testing, including dynamic, balanced-armature, and planar-magnetic designs.)
• Build quality should be on a par with the price you are paying. All portable amps should be able to handle frequent unplugs, replugs, button pushes, and dial turns without falling apart.
• The ability to decode a variety of audio formats is helpful, including a maximum audio resolution of at least 24 bits/192 kilohertz (the highest resolution now available through streaming and from most download services), as well as audiophile-oriented options such as DSD and MQA. (We haven’t seen evidence showing that either DSD or MQA delivers a consistent and readily perceptible benefit, but there are quite a few audiophiles who value these technologies.) We also look for companies that make an effort to update their firmware over time as new formats become popular.
• Brand reliability and warranty coverage go hand in hand. It’s important to know that a company will stand behind its devices, and it’s even more important to know that a company will be responsive when you need to call customer service.

With the above criteria in mind, we searched for new portable headphone amps to test by going through dozens of audio-company and retail sites; scanning reviews in audio publications such as Sound & Vision, What Hi-Fi, SoundStage Xperience, and Stereophile; and checking out audio forums like Head-Fi and AVS Forum. Last, we scanned the reviews on Amazon and Crutchfield to see if any problems consistently popped up in the comments. This category has greatly expanded since our last major update, and there are far more new amp/DACs than any one article can practically cover, so we focused on models that got generally good reviews or that we were simply curious about.

For the most recent update of this guide, we tested 13 new headphone amps ranging in price from $11 to $300, as well as a couple of inexpensive dongle-type amp/DAC models. This round brought the total number we’ve tested for this guide to 33.

The tests we’ve done for this guide are the most complex evaluations our audio team has conducted to date. People make a lot of claims about headphone amp/DACs and their ability to improve the sound quality of headphones. We wondered how much of that improvement was perceptible in controlled listening tests, and how much was placebo or confirmation bias. We devised a testing plan that was as unbiased as possible so that we could take price, brand, and design out of the equation.

To do this, I set up my custom-built switcher, which enabled us to have four amps set up with four computers as sources and allowed each listener to compare the different amps without knowing their identities. The switcher contained only one component per audio channel: a relay of the same general type commonly used in many of the best power amplifiers and preamps. Electrically, the effect of the switcher was approximately the same as connecting a 1-foot extension to a headphone’s cord. All four computers ran the same software (foobar2000) and had the same digital music files (AAC, MP3, CD-quality, and high-res). The proctor matched the output levels by running a 1-kilohertz tone through each amp and measuring the output in millivolts using an NTi Audio Minilyzer ML1 audio analyzer. We adjusted until we had a matching variable of ±0.2 decibel. This process ensured that our panelists wouldn’t be swayed by one option sounding louder or softer than the others. Each panelist sat wearing headphones with their back to a screen that blocked them from viewing which amps were currently in use.

Each panelist listened to the same track through all four amps and switched between sources at will, identifying each only by the number on the dial. They could listen to as many tracks as they needed to make a determination; each panelist ended up requiring three to five tracks. The tracks were test files that the panelists supplied, chosen from the tracks we commonly use to test headphones and speakers. Each panelist took notes, after which the proctor would then swap in another set of four amps. We repeated this process until each panelist had heard all the contenders.

After reviewing their notes, each panelist could then request (by grouping and number) certain amps that they wanted to hear again and compare directly. At this point the panelist would pick favorites for that set of headphones.

Because we know that not all headphones are created equal, and may not respond in the same way to a headphone amp/DAC, we tested our contenders using specifically chosen headphones, including over-ear models with different driver types and widely varying sensitivity, and earphones using balanced armatures. Our initial round of testing included the HiFiMan HE1000 V2, Shure SE535, and Sony MDR-7506, while our latest round employed the AKG K371, Beyerdynamic DT 880 (600-ohm version), Etymotic Evo, HiFiMan HE6se, and Sendy Peacock. With each new pair of headphones, the proctor changed the groupings and the switch number assignments to avoid confirmation bias.

After the proctor compiled all the panelists’ listening notes, they finally revealed to the panelists which amp corresponded to the group and switch numbers. From there, we discussed our favorites, our least-favorites, the contenders’ designs, and their prices.

We also did an informal power test to see how loud the amps could get under worst-case conditions. We connected each one to the two most difficult-to-drive headphones we had on hand: the HiFiMan HE6se (rated at 83.5 dB sensitivity but reaching just 79.2 dB in my measurements) and the 600-ohm version of the Beyerdynamic DT 880. We then played vocalist/saxophonist Camille Thurman’s version of “September in the Rain” (video), which was recorded on the audiophile label Chesky Records and mastered very conservatively, so it’s much less loud than modern pop recordings. Many albums recorded before about 1995 and never remastered are similarly quiet, so we wanted to make sure that any amp we recommended would be usable with all the recordings you might want to play, through any headphones you might want to use.

We devised a testing plan that was as unbiased as possible so that we could take price, brand, and design out of the equation.

I also ran some audio tests (including output-impedance measurements) using an Audiomatica CLIO 12 FW audio analyzer to make sure none of our top picks had any performance anomalies that our ears didn’t pick up and to get a precise idea of how loud they could play and what types of headphones they could be trusted to drive. Most important, I measured the power output into 32 ohms (more or less the most common impedance for headphones), as well as 250 ohms and 600 ohms—both of which are uncommon impedances for headphones but still used in a few audiophile and professional models. I then verified these measurements by redoing them using an NTi Audio Minilyzer ML1 audio analyzer. The power-output measurements specify maximum output at 0.5% total harmonic distortion or less. Note that in amplifiers, doubling the power may seem impressive, but it yields only a 3-decibel increase in volume—about three clicks on a typical car-stereo volume control—which is noticeable but not dramatic.

Finally, I did some tests to see how our picks that draw power from the source device would affect smartphone battery life. I ran a fully charged Google Pixel 4a phone at its maximum volume through a set of HiFiMan Deva headphones connected with a cable. The Deva set posed a challenge because its rated sensitivity was just 93.5 dB, which meant the Pixel 4a could get the Deva only up to a fairly soft listening level. I ran The Weeknd’s “Blinding Lights” on repeat, with the display off, until the phone’s battery power reached 90%. I then connected each headphone amp to the Pixel 4a, connected the headphones to the amp, and matched the volume to the original playback volume of the phone, using a GRAS 43AG ear-and-cheek simulator and the sound-pressure level meter built into the Room EQ Wizard PC app. I then ran the test again, clocking the amount of time it took for the phone’s battery power to drop to 90%. I also ran the test once more with the volume boosted 6 decibels—a typical volume increase that listeners using somewhat inefficient audiophile headphones would probably want.

Overall I found that, although the typical power drain that headphone amp/DACs place on a smartphone’s battery life is surprisingly high, the effect is fairly minor if you listen for, say, two hours a day. People who charge their phone every day might never notice the effect the amp has on their phone’s battery life, though it could be an issue over a single long listening session—such as on a lengthy flight where you can’t charge your phone. Note that your results will vary because smartphones are complicated devices whose power draw can be affected by innumerable factors—and of course, we don’t know what phone or headphones you use or how loud you play your music.

The EarMen Eagle packs impressive power into a super-compact, affordable design, but it lacks some audiophile-oriented features like MQA support and balanced audio output.

*At the time of publishing, the price was $130.

The EarMen Eagle is our top pick among portable headphone amplifiers because it offers such an appealing combination of convenience, performance, and affordability. It’s powerful enough to drive all but the least sensitive headphones to satisfying volumes, and it sounded as good as any of the other amp/DAC models we tried. Its integrated USB-A plug lets it connect directly to many computers, and an adapter cable allows it to connect to devices with USB-C output. It doesn’t have much in the way of extras—it lacks MQA support and balanced audio output, for example—but it has everything that most listeners need, and it slips almost unnoticed into a pants pocket.

The Eagle looks like a USB memory stick, with a male USB-A connector on one end and a single ⅛-inch (3.5 mm) headphone jack on the other. It can plug directly into computers that have USB-A jacks, and it can also connect to mobile devices with USB-C jacks through an included adapter cable. Connecting to an iOS device requires the purchase of a Lightning-to-USB adapter. The Eagle’s 2¼-inch chassis and half-ounce weight make it easily pocketable.

In our listening tests, the Eagle sounded as good as any other amp, including models priced more than twice as much. We didn’t find anything distinctive in the character of its sound, which is a good thing. It performed well with almost all the headphones and earphones we tried, with just one exception we’ll discuss in the Flaws but not dealbreakers section.

The Eagle replaced the AudioQuest DragonFly Red as our top pick because it offers more power at a lower price in a similar size. The Eagle topped out at 79.1 milliwatts into 32 ohms, in contrast to 46 mW for the DragonFly Red (and just 29.4 mW when we held the maximum allowed distortion to 0.5%). On the Eagle we also measured 16 mW into a 250-ohm load and 6.7 mW into a 600-ohm load, which was not impressive but was still enough to get our 600-ohm Beyerdynamic DT 880 headphones up to a moderate listening level. Output impedance measured 3 ohms, low enough that it won’t affect the sound of headphones or earphones.

Because the Eagle doesn’t have an internal battery, it must draw power from the device to which it’s connected. In our tests, running the Eagle at the same volume as our Google Pixel 4a’s max volume increased total power consumption by about 62%, while running it at a volume 6 decibels higher increased power consumption by about 70%. That sounds like a lot, but by our calculations, if you use the Eagle for two hours per day, it would reduce the Pixel 4a’s battery life by only about 6%.

For what it’s worth, this EarMen amp also handles higher file resolutions than the AudioQuest model does: 32 bits/384 kHz for the Eagle versus 24/192 for the DragonFly Red. However, no streaming services and few downloaded files offer enough resolution to take advantage of this feature. The Eagle also works with the audiophile-oriented DSD and DXD formats.

The EarMen logo on the top lights up in cyan when the amp is idling and in green when music is playing.

The Eagle also lacks a balanced audio output, a feature that some headphone enthusiasts like—but one that doesn’t, in our opinion, produce an improvement in sound quality. And it doesn’t support microphone pass-through, which allows you to use the amp while talking on the phone if your headphones or earphones have a built-in microphone.

When we used the Eagle with the least sensitive set of headphones in our possession, the HiFiMan HE6se (rated at 83.5 dB sensitivity), it didn’t have enough power to achieve a satisfying volume on Camille Thurman’s recording of “September in the Rain.” The result was loud enough for light listening, but the impact of the drums and the groove of the tune were lost. However, with the more typical R&B, rock, and pop mixes we played, the Eagle played plenty loud enough through the HE6se.

The Eagle also doesn’t give the listener any indication of what audio format they’re hearing; many other amp/DACs have different-colored indicator lights that show the digital sample rate of the material they’re playing. However, this information should be available from the source device.

This large headphone amp is almost three times as powerful as our top pick and runs on a built-in rechargeable battery, but it feels almost like carrying an extra phone with you.

*At the time of publishing, the price was $190.

For serious audio enthusiasts who need, or just want, more power, the iFi Hip-dac2 is an ideal choice for a portable headphone amp. The Hip-dac2 (which replaces the original Hip-dac, a former pick in this guide) offers two big advantages over our smaller picks. First, it has the power to drive almost any pair of headphones to ample listening levels with any music recording. Second, it has its own integrated rechargeable battery, so it doesn’t affect your mobile device’s battery life. The only downside to the Hip-dac2 is that it’s much larger and heavier than the other models we recommend.

The Hip-dac2 is roughly the width of a typical smartphone but shorter (3⅞ inches) and thicker (9/16 inch). It’s quite a bit heavier than our other picks, at 4.8 ounces, but it packs many more features and much more power. The top panel has a volume knob/power switch and two headphone outputs: a standard ⅛-inch (3.5 mm) jack and a 4.4 mm Pentaconn jack for a balanced connection, with electrically separate feeds for the left and right channels. A balanced connection is available on many audiophile headphones and earphones; it doesn’t really improve sound quality, but in the Hip-dac2’s case, the balanced output offers extra power. The Hip-dac2 also has a Power Match button that supposedly optimizes the output for your headphones, though we pretty much had to use it all the time—without it, the volume was too low. The XBass button boosts the bass, a feature that some people will enjoy even if we didn’t.

The Hip-dac2 requires you to connect it to your audio device by plugging in a male USB-A connector, which is a little unusual, but it comes with the necessary cables to connect to USB-A and USB-C devices. Connecting to an iOS device requires a Lightning-to-USB adapter. The Hip-dac2 charges through a USB-C jack, and a USB-A–to–USB-C charging cable is also provided. You can add a case from iFi or other vendors.

The Hip-dac2 got the best sound from all the headphones we tried it with—not because its amplifier and digital-to-analog converter sounded more refined, but purely because the Hip-dac2 has so much more power than the USB-stick and dongle-style amps we tried. From the unbalanced output, the Hip-dac2 maxed out at 223.8 milliwatts into 32 ohms, 37.1 mW into a 250-ohm load, and 15.2 mW into a 600-ohm load. From the balanced output, it produced 246.1 milliwatts into 32 ohms, 37.7 mW into 250 ohms, and 15.7 mW into 600 ohms. Output impedance measured 1.8 ohms from the unbalanced output and 0.8 ohm from the balanced output, both low enough amounts that they’ll have no effect on the sound of headphones or earphones.

The Hip-dac2 can handle standard digital audio in resolutions up to 32 bits/384 kilohertz (far above the typical max of 24 bits/192 kilohertz from the best streaming services), and it also handles the relatively uncommon DSD and DXD download formats. It does MQA, too. The LED on the front panel glows in different colors to show you the format and resolution of the music you’re listening to.

Beyond its larger size, another potential drawback of the Hip-dac2 is that it’s inconvenient for use with computers. It will work fine with a computer, but because the Hip-dac2 doesn’t draw its power from the computer, you’ll have to keep recharging the battery or leave the unit connected to a USB power supply.

It also lacks microphone pass-through, so you can’t use the inline microphone on a set of headphones when the Hip-dac 2 is connected. If you need a powerful amp/DAC with mic pass-through, consider the THX Onyx.

The Hidizs S3 Pro is the size of a stack of five nickels, yet it has enough power to drive most headphones. But the design feels a bit flimsy.

$70 from Amazon

May be out of stock

Audio enthusiasts who need a portable headphone amp/DAC because their headphones need just a little more power than their phone or tablet can deliver will find the Hidizs S3 Pro to be an affordable and effective option. It’s essentially a little metal puck, similar in size to a stack of five nickels, connected by a cable to a USB-C plug. It’s so tiny, it can ride in a jeans pocket and go unnoticed, yet it has enough power to drive most headphones to satisfying volume levels. The downside of the S3 Pro: Although ours showed no signs of wear during a few weeks of use, it seems more fragile than our other picks.

The S3 Pro connects directly to devices with USB-C jacks and includes an adapter that allows it to connect to USB-A devices. As with the EarMen Eagle, only a ⅛-inch (3.5 mm) headphone jack is provided for output. The S3 Pro weighs just a quarter of an ounce, so it’s like having a couple of extra coins in your pocket. The whole unit measures only about 3½ inches long.

In two separate tests, the S3 Pro was the only amp that Lauren singled out for comment, praising it for seeming to have a “little more dexterity in the bass” than the other under-$100 models. The S3 Pro came pretty close to the EarMen Eagle in powering fussy headphones; it didn’t quite get the low-sensitivity HiFiMan HE6se headphones up to a satisfying volume when we played Camille Thurman’s take on “September in the Rain,” but it did fairly well with the 600-ohm Beyerdynamic DT 880 headphones.

In our measurements, the S3 Pro performed surprisingly well for its price. Its maximum output measured 56.6 milliwatts into 32 ohms, substantially better than what we saw from our previous top pick, the AudioQuest DragonFly Red, and only about 1.5 decibels less (a barely noticeable difference) than the EarMen Eagle could muster. Performance into higher-impedance loads wasn’t impressive—7.7 mW into a 250-ohm load and 3.2 mW into a 600-ohm load—but, again, for the price, it’s fine. The output impedance was a little high at about 7 ohms, but still not high enough to noticeably change the sound of headphones.

Surprisingly, the S3 Pro offers almost the same digital-file compatibility as the bigger, pricier Hip-dac2 does: standard PCM digital audio at resolutions up to 32 bits/384 kHz, and both DSD and MQA support. An LED on the top glows red for standard-resolution audio, blue for high-res, and pink for MQA. The S3 Pro also has microphone pass-through, so if you connect a set of headphones with an inline microphone, you’ll be able to carry on phone conversations while the S3 Pro is connected.

The S3 Pro’s main flaw is that its design seems fragile. The cable comprises four flexible, relatively thin strands twisted together, so it’s conceivable one of them could be nicked or even severed by a key in your pocket. The design doesn’t allow for much strain relief on the cable, so we worry that it might eventually fail. But I carried the S3 Pro in my pocket for two weeks, using it during my daily dog walks, and it showed no signs of wear.

Other flaws—namely, its inability to get difficult-to-drive headphones really cranking, as well as the extra power draw it puts on a smartphone’s battery—are inherent to its design and price, and thus forgivable. In our tests, the S3 Pro increased the power consumption of the Google Pixel 4a by 59% when playing at the same max level as the phone could achieve and by 66% with the volume raised an extra 6 decibels, which equates to about a 5.5% decrease in phone-battery run time if you use the S3 Pro for two hours per day.

Most headphones are rated to deliver somewhere around 100 dB from a 1 mW signal, which is pretty loud. For reference, the World Health Organization recommends that the equivalent continuous sound level (or Leq) should be kept below 70 dBA for music played through headphones or limited to one hour at 85 dBA. You can read our thoughts on safe listening for more context. For every doubling of milliwatts, you get 3 decibels more output, so with a set of headphones rated to deliver 100 dB at 1 mW, you get 103 dB from 2 mW, 106 dB from 4 mW, and so on.

Because this category is so large, with new brands appearing often on Amazon and elsewhere, it’s impossible for us to offer comprehensive coverage of headphone amp/DACs. We think we’ve covered all the major players for now, but if there’s a model you’re curious about that we haven’t included in our coverage, let us know in the comments section below.

All of the headphone amp/DAC combos we’ve tested have sounded very similar or identical, and most offer enough power even for somewhat hard-to-drive headphones—so most of the models listed below will work just fine from a sound-quality perspective. What differentiates them is each model’s combination of features, price, and output power. But really, excluding a few duds listed at the bottom, if you prefer any of the following designs over our picks, that’s okay.

Apogee Groove: During our brand-concealed tests, the USB-powered Groove sounded a bit softer in the mids and a tad more coarse in the highs but still quite good. It offers a lightweight, easy-to-use design plus its own digital volume control. The Groove works with Mac, PC, iOS, and Android devices, but like the AudioQuest DragonFly Red, it drains power from mobile devices.

AudioQuest DragonFly Black: The sound of the DragonFly Black was nearly identical to that of the more expensive DragonFly Red—which is to say, great. We heard lots of detail and sparkle on the highs, agile lows, and an even, spacious sound in the mids. But the DragonFly Black is less powerful than the Red. AudioQuest claims 1.2 volts or 4.5 mW, which is really more suitable for efficient earbuds.

AudioQuest DragonFly Cobalt: This upgraded version of the DragonFly Red is substantially more expensive, but in our tests it didn’t sound notably different than the Red and didn’t offer significantly more power.

AudioQuest DragonFly Red: This is our former top pick, and it has the same USB-stick form as the EarMen Eagle. It still offers a nice mix of power, sound quality, and convenience, but it’s been around for several years now, and many newer models offer more power for the same price or even less.

Centrance DACport HD: The DACport HD doesn’t offer much volume in its low-gain mode, and the switch to toggle to the high-gain mode is recessed, so you’ll need to track down a paper clip to flip it. The plasticky design feels cheaply made, especially compared with the competition. Overall, it sounded fine, if a little quiet, in our tests, but nothing about the DACport HD overwhelmingly impressed us, especially when we considered the $180 price.

Clarus Coda: This pricey model seems aimed more at audiophiles wanting an affordable DAC than at headphone enthusiasts. Its measured output was only 15 mW into 32 ohms.

Cubilux USB Headphone DAC Adapter: We couldn’t resist giving this $12 amp a listen. At only 5.3 mW maximum output into 32 ohms, it offers about 3 decibels more output than a Samsung Galaxy S10 smartphone does. Though it’s no sonic upgrade, if you just need a really cheap amp/DAC, this one will do.

EarMen Sparrow: Technically, this little amp is impressive, measuring 123.7 mW into 32 ohms from its unbalanced output and 153.7 mW from its 4.4 mm balanced output. But we experienced connection problems with some source devices.

EarStudio HUD100 MK2: This compact amp has pretty good power output for the price; we might have included it on our list of picks except that we prefer the slimmer designs of the EarMen Eagle and Hidizs S3 Pro.

FiiO Q1 Mark II: Landing in the middle of the pack, the Q1 Mark II sounded perfectly acceptable to us. It had a little too much low end, which made male vocals sound slightly recessed, and it didn’t quite have the sparkle and life in the highs that our top picks exhibited.

FiiO Q5s: Previously we made this amp a pick for people who need more connection options, since it supports analog, digital, and Bluetooth connections; it also has a built-in battery. But it’s not as powerful as the iFi Hip-dac2, and its availability has become spotty. It may be discontinued.

Ikko Zerda ITM01: This unusual amp has a magnetically attached cable connection that requires a proprietary cable. It offers loads of power for the price (124.9 mW into 32 ohms), but we read reports of intermittent connections—and we experienced the same problem ourselves.

Micca OriGen G2: Though technically portable, this 5-inch-long amp is really more of a desktop model, with a large volume control on top, an optical digital input in addition to USB, and dual headphone outputs. It offers a lot of power—380 mW into 32 ohms—but it’s impractical for portable use.

miniDSP IL-DSP: The IL-DSP offers EQ settings, which might be amusing for some folks to fiddle with, but the amp isn’t exceptionally powerful, and the initial setup is a bit of a complicated chore. The IL-DSP sounded fine to us with lower-impedance headphones, but the experience is better geared toward someone who enjoys fussing over sound profiles as a hobby.

Monoprice Monolith Portable Headphone Amplifier 24460: The most powerful model we measured for our spring 2020 update, the 24460 was able to get even more volume out of 600-ohm headphones than the iFi Hip-dac2 (23.3 mW output into 600 ohms for the 24460, versus 15.2 mW for the Hip-dac 2’s unbalanced output). It sounds great, feels well built (if a bit heavy), and has a three-year warranty. The problem is that it’s typically a third pricier than the Hip-dac2. Although the 24460 does have some neat features for you to noodle around with (like filters and Sensaround), we found that, with well-tuned headphones, we didn’t need all that.

Monoprice Monolith USB DAC 29512: If you’re looking to save a few bucks, this is a solid little device. It’s not quite as powerful as our picks, and it may not get firmware updates as frequently, but if you don’t care about MQA or newer encoding, that may not matter to you. We do wish that the volume control were a dial rather than buttons with predetermined steps, but that’s a minor quibble. If you want a budget amp/DAC to drive headphones under 250 ohms, the 29512 will work just fine.

NextDrive Spectra X: Apple-device owners should skip this one, as the USB-C version is incompatible with iOS, and updating the Camera Adapter can make the USB-A version incompatible, as well. As for Android and PC-laptop use, the Spectra X fares fine on 32-ohm gear. But for higher-impedance headphones above 250 ohms, you may discover that you don’t have enough volume. For PC/Android users, if you like the design, the Spectra X is okay, but our picks are more powerful and can decode more formats.

Questyle M12: This especially compact amp/DAC came within a fraction of a milliwatt of the THX Onyx on our 250- and 600-ohm power tests, which is impressive for a model at this price. But with performance measuring at just 40.6 mW into 32 ohms, it fell short of our top picks—although it does support MQA, which the EarMen Eagle does not.

Sabaj DA3: This affordable amp is feature-packed, with a 2.5 mm balanced output in addition to the standard 3.5 mm unbalanced output, as well as an LCD screen that tells you the sampling rate of the audio you’re listening to. Output in our tests was pretty impressive at 58.3 mW into 32 ohms from the unbalanced output and 120.2 mW from the balanced output. However, this model is relatively large at about 3¾ inches long, and its sharp-cornered design makes it less pocketable than most competitors.

Sony PHA-1A: The PHA-1A’s sound quality consistently ranked near the top of our lists, but it sounded slightly more two-dimensional than our top picks, with a bit of midrange coloration. Ultimately, it was the PHA-1A’s larger, heavier build and shorter battery life that nudged this model out of the winner’s circle.

We encountered a few amp/DACs that our panelists didn’t like, and we recommend skipping the following models even if they’re available at a discount:

Apple USB-C to 3.5 mm Headphone Jack Adapter: Producing just 3 mW of power into 32 ohms, and less than 0.05 mW into higher-impedance loads, Apple’s dongle-type amp/DAC is only about as good as the amps built into smartphones. For a few bucks more, you can get more than 50 times as much power from the Anker A8195.

Creative Sound Blaster E5: Although the overall sound wasn’t objectionable, our panelists liked most everything else we heard better. I described the sound as “somewhat dull, crude, and edgy when compared to the others,” and John and Lauren agreed. Lauren also found it to have lower-end bloat and a more 2D sound quality than most of the other DACs.

FiiO i1: Since the i1 was made for Lightning iOS devices, our panel conducted brand-concealed tests of this model against Apple devices. Surprisingly, the MacBook Pro and iPad Mini, through their built-in headphone jacks, and the iPhone 7, through its included headphone dongle, sounded nearly identical with the volume matched. We were able to hear a distinct difference between the i1 and the Apple devices, but our panel said it was a lateral move: The i1 definitely sounded flatter, both in the frequency-response sense and in the spatial sense. The Apple devices were slightly more boosted in the lows and highs, but that made them sound more 3D. We all agreed that the i1 changed the sound, but we didn’t think that change improved the sound.

iFi Nano iDSD Black Label DAC/Amplifier: This model is more of a portable desktop device than a portable headphone amp. It has two settings, measure and listen, which seem to mildly alter the low frequencies. When we turned the volume dial, it produced some slight crackling noise, which shouldn’t happen in this price range. Overall, we were disappointed, especially in comparison with how much we liked the Hip-dac2 by the same company.

JDS Labs C5D: The C5D truly surprised—and disappointed—our panel. JDS has a fantastic reputation, but the C5D was noticeably muddier, bassier, blurrier, boomier, and noisier than any of the other amp/DACs we tested, even though we tested it with its tone switch set to the neutral position. It was the only model in our brand-concealed tests that our panel singled out as actively disliking.

XtremPro X1-1: Measuring at just 0.5 mW maximum output into 32 ohms in our tests, this amp produced only about one-fifth the output of a Samsung Galaxy S10 smartphone.