Remove the LEFT Earpiece from the charging case. You’ll hear an audio prompt indicate “HELM ON, Power Level." The volume was so loud it nearly blasted out my ears and anything over 5 percent volume within the Quobuz app was ridiculously too loud. The only way I found to fix the problem was to go into the Audio MIDI app and reduce the master volume to 50 percent or less. I’ve experienced some oddities with the Qobuz desktop app before, and if you use the Helm Bolt with Qobuz on a Mac, you should be cautious about this volume anomaly I experienced. Theo Nicolakis / IDG I’m fortunate to have the AudioQuest DragonFly Cobalt, THX Onyx, and Clarus Coda on my desktop every single morning while I enjoy my post-run coffee at 6 a.m., but none of them blow up my skirt that much anymore. The Helm Bolt has an LED indicator to show you the signal format and sampling rate. Magenta indicates the presence of an MQA signal. A revelatory listening experience

going. The TRRS 3.5-mm connector (through both Bolt and DB12) also makes the combo a gamer-friendly device because it lets you use any headphone's microphone.On a more fundamental level, the Bolt’s primary intent is to better the sound quality of a laptop or smartphone’s 3.5mm headphone output (should it have one). That makes the HELM dongle not just a good idea for hi-res audio but for all audio, including the CD-quality streams that remain the bread and butter of Qobuz and Tidal’s hi-fi tiers and the lossy streams that spill from Spotify and Apple Music. Yes, a DAC like this will improve the sound of Apple Music and Spotify!

The next time you use your headphones, remove the LEFT from the charging case, then the RIGHT, they will automatically pair and connect to your device. There is no need to open your Bluetooth settings.Not only is it THX-certified, but it also supports MQA and is designed with a USB-C input and 3.5mm headphone output. iOs requires a Lightning to USB Camera Adapter. Listening Equipment: FOSTEX T40RP MK3, TForce Yuan Li, SeeAudio Bravery, VE ZEN 2.0 SLQ 320Ω , 7Hz Timeless, Shure KSE1500. Source: USB 3.2 Samsung S20, USB 2.0 Xiaomi Redmi 10, HiBy Player & Tidal MQA DELIVERING MAXIMUM VOLUME +12dB with Near Zero Distortion, Greatly Improving Sound Quality and an Independently Controlled Bass Boost +6dB I tested the Helm Audio Bolt with my Samsung Galaxy S9+ Android phone, Windows 10 computer, and a Linux laptop. Each platform worked flawlessly whether over the Bolt’s built-in USB-C port or with the included USB Type-A adaptor. Upon plugging the Bolt into my Galaxy S9+ and firing up Tidal, I received a notification to allow Tidal to access Helm MQA which I accepted. Similarly, on my Windows PC, it was a breeze to select the Helm MQA as an output device.

Comparisons between the two dongle DACs are inevitable. Both are very capable DAC/Amps that assure excellent sound quality from their respective implementations of the same DAC chip (ESS ES9281PRO). Both employ isolation from the USB circuitry and meet THX standards. Onyx has one important advantage, it’s just a little more powerful with a few additional mW into a given headphone’s load and the efficiency of the AAA architecture makes it punch well above its rating. But that little bit of extra power also means it will use just a little more of your phone or other portable source device’s battery’s life. But overall sound quality differences are negligible at a given volume.Unlike THX Onyx however, the amplifier portion of Bolt is not a THX AAA (Achromatic Audio Amplifier. Although HELM Bolt is THX certified for meeting the standard’s low noise and crosstalk requirements (THD+N%: 0.0008 at <150 Ohms, 0.0013 at >150 Ohms). The housing is made of metal and feels premium. The cable is cotton-shielded against outside interference and the strain reliefs on both ends could be a bit longer and sturdier. Amplified Audio Output and Headphone Output Level Matching An average increase of +6 dB in devices with combined USB-audio output (where a dedicated headphone audio output isn't available.) Headphone output level automatically detects headphone impedance and sets level accordingly: (1V for 150 ohms.). Note: Increased dB levels vary based on each type of set up. I was pleasantly surprised that it could drive my 25 ohm Ether CX headphone to reasonable level without distortion. Switching to Sennheiser HD650 produce good power and again, no sign of distortion. Quite adequate for on the go job. The BOLT DAC/Amp looks to have a pretty sturdy build. It’s composed of Aluminium and soft-touch plastic, with a braided tangle-resistant cord. It’s super small, at less than four inches long, and only weighs about a quarter ounce.