Audio magic on the go. | HELM Audio DB12 AAAMP portable headphone amplifier hands-on

The HELM Audio DB12 is tiny considering the hardware inside. Most headphone amps range from the size of a portable hard drive to the same volume as 3-4 stacked DVD cases. At 70 x 22 x 12 mm (L x W x H), or 2.76 x 0.87 x 0.47 inches, the main body of the DB12 is about the size of six sticks of gum in a stack. The male 3.5 mm cable is roughly 66 cm (26 inches) long including the connector, while the female 3.5 mm line extends about 8.9 cm (3.5 inches) out the other side.

As a result, the DB12 fits easily into a pocket or backpack, and since it's battery-powered and charges via USB-C, it doesn't require a bulky power adapter. That's nice considering it's targeted for use with smartphones.

The body of the DB12 is encased in brushed aluminum. It feels solid and resists fingerprints. The buttons are big and clicky, although the volume up button ("+") is a bit sticky and has an unpleasant crunch to the click. Additionally, the metal shield surrounding the female jack slipped off my review unit. These small flaws may be particular to my unit, though. The shielded silver cables are braided and haven't frayed in the month I've used the DB12 despite many trips in and out of pockets on my bag.  The power slider is also well-built and stays in place.

Overall, the DB12 is a tiny but solid device, but the quality doesn't quite meet expectations for a US$179.99 device.

The DB12 is essentially a powered headphone cable. Its primary purpose is to replace the amplifier in whatever device it's plugged into. The onboard amps of most smartphones and laptops are good enough for general consumption, but an external amp can both increase volume output (to capture more subtle sounds) and clean up distorted or noisy audio.

The DB12 features THX's Achromatic Audio Amplifier (AAA) design. This technology essentially helps to eliminate distortion and noise for cleaner audio. It also lessens electronic noise from power sources that are present in some amps.

The DB12 does a remarkable job in both respects. The tiny amp works wonders with both my desktop (Beelink GT-R) and smartphone (iPhone 8). Thankfully, it works with Lightning-to-headphone and USB-to-headphone adapters without any fuss. I tried several lossless audio files on both devices with my Audeze Mobius headphones, which have massive 100 mm planar magnetic drivers and are designed for gaming and hi-fi audio.

With both devices, using the DB12 is night and day. Without the DB12, audio sounds good but feels flat and colorless overall. Once the DB12 is switched on, the music comes to life. Volume jumps much higher, but that's only the beginning of the story. Even at similar volume levels, the DB12 brings out bright harmonics in piano pieces that are otherwise lost without the tiny amp. 

Perhaps the most noticeable contrast for me lies with the sample drum feature I use (LessLoss Drums Duet #1). I'm a semi-professional drummer and percussionist with two decades of experience under my belt. I'm typically disappointed with the sound quality of drum features, even when listening to them in a lossless format with a decent set of cans. Without the DB12, this particular drum feature sounds like a flat recording; the various percussion instruments miss the subtleties inherent in each strike.

When I turn the DB12 on, the music becomes a live show. The amp enhances each ghost note on the snare and each subtle slap on the congas. It really must be heard to be accurately described. The bass boost option also pumps the low end without losing clarity.

The DB12 offers significant and readily noticeable improvements to audio quality, clarity, and volume. It takes the audio experience to a level unattainable with an onboard AMP.

Keep in mind that the DB12 does nothing to fix problems with a device's digital-to-audio converter, or DAC, which is arguably more important than an amplifier. A poor DAC will choke audio quality, and the DB12 can't do anything to correct it. However, most devices have decent DACs that can handle lossless audio, making the DB12 a very nice accessory for audiophiles on the go.