Denafrips Hermes 12th Review: Are DDCs Just Snake Oil?

DDCs, or Digital-to-Digital Converters, are a controversial addition to HiFi setups. Some say it’s useless snake oil, while others swear it improves the audio quality tenfold. When I got my hands on the Denafrips Hermes 12th, I had to find out.

Design & Build Quality

This is an area where Denafrips consistently shines, and the Hermes is no exception. Right off the bat, you can feel the heft. This isn’t some lightweight plastic box with a raspberry pi inside. It’s a substantial piece of equipment, reflecting the quality of the components inside and the robust construction. First impressions matter, and the Hermes 12th doesn’t disappoint.

The front panel, made from high-quality aluminum, is available in two classic finishes: black and silver. Both options will complement any audio setup, as those are rather neutral colors. The black version, which we have here, offers a sleek and modern look, while the silver option provides a more traditional hi-fi vibe. The rest of the chassis is constructed from sturdy metal, ensuring durability and shielding against unwanted interference from the outside world. Denafrips always makes their components with virtually no plastic parts, and this one is no different.

The Hermes 12th isn’t just about looks, though. It’s built to last. The robust construction inspires confidence, and you can tell that this unit is designed to be a long-term investment in your audio system. Some cheap devices out of China just feel like they’re gonna break in a month - this one isn’t one of them. The device’s weight is also reassuring, indicating the quality of the components inside and enclosure.

While we can’t delve too deep into the internal design without taking it apart, as I’m kinda scared that I’ll break something - Denafrips is known for using high-quality components in their products, plus they include pictures of the inside on their website. Looking at them, the Hermes 12th is no exception, featuring an oversized 80VA O-Core shielded transformer and multiple sets of ultra-low noise, precision linear power regulators. This ensures that all circuits receive a clean and stable power supply, which is crucial for optimal performance.

In terms of size, the Hermes 12th is relatively compact, making it easy to integrate into your existing setup. It’s not too large or bulky, so you shouldn’t have any trouble finding a spot for it on your rack. However, for desktop setups, it’s a bit wide, which can be problematic for some.

Overall, this DDCDigital-to-Digital Converter - a device that converts one digital audio interface to another (USB to I²S, USB to S/PDIF) while reclocking the data with a low-jitter local oscillator, often as a "bridge" between a computer and a digital input on a DAC. impresses with its build quality and design. It’s a well-crafted piece of equipment that exudes quality and sophistication. The minimalist aesthetic, combined with the robust construction, makes it a standout in its class. One thing I especially appreciate here regarding its appearance is the way it can fit in almost every setup with all styles of electronics.

Inputs & Outputs

The Hermes offers a comprehensive selection of inputs and outputs, giving you plenty of options to integrate it into your system. This flexibility is key for optimizing your digital audio chain.

Starting with the inputs, we have the standard power connector, of course. Then, for digital audio, we’ve got a USB input, which is ideal for connecting directly to your computer for playback from streaming services or your personal music library. Next, we see an AES/EBUA professional digital audio standard electrically identical to SPDIF but using balanced XLR connectors with higher voltage for longer cable runs. input, a professional-grade balancedA signal transmission method using two opposite-polarity signal lines plus a ground; noise induced on both lines is cancelled at the differential input. connection often used with high-end digital sources. Optical TOSLINKAn optical S/PDIF digital audio interface using a plastic fibre and a red LED, common on TVs, soundbars, and consumer DACs. Limited to 24-bit/96kHz stereo PCM in practice; longer runs need glass fibre for stability. provides another option for connecting digital sources, particularly those where electrical isolation is beneficial. A Coaxial input is also included for compatibility with a wide range of digital devices. Finally, and this is a key feature for advanced setups, we have two Clock BNC inputs. These allow you to connect an external clock, like Denafrips’ own clock, to further refine the timing and reduce jitterTiming irregularities in the digital audio clock that cause correlated noise sidebands, audible as a subtle smearing or loss of focus., taking your digital audio performance to the next level.

Moving on to the outputs, the Hermes 12th again offers a good variety. We have a Coaxial output, providing a standard digital connection to your DACDigital-to-Analog Converter - a device that translates binary audio data into an analog electrical signal that can be amplified and heard.. An Optical output mirrors the input option, offering flexibility in connecting to different devices. Now, here’s where things get interesting. The Hermes 12th features two I²SInter-IC Sound - a digital audio interface standard using separate lines for data, bit clock, and word clock. Used inside DACs natively; some high-end DACs expose I²S via HDMI for connection to dedicated transports. outputs: one over RJ45 and the other over HDMI. I²S is a digital audio connection that transmits the digital audio data and clock signals separately, minimizing jitter and improving sound quality. Having both RJ45 and HDMI options ensures compatibility with a broader range of DACs that support I²S. Finally, we have two AES/EBU outputs. These balanced outputs can be used to connect to two separate DACs for bi-ampingDriving the low-frequency and high-frequency sections of a speaker with separate amplifier channels, requiring either passive or active crossover filtering. or other advanced configurations.

Features

One of the standout features is the variable, selectable I²S output. You can actually select between different I²S pin configurations. This crucial feature ensures compatibility with various DACs, even those with non-standard I²S implementations, which are unfortunately quite common. With this feature, you can make it work with everything.

For the serious audiophile, this DDC provides the option to use external clocks. With dedicated clock BNC inputs, you can connect a high-quality external clock, like Denafrips’ own, to further refine the timing accuracy of the digital signal. This can result in an even more significant reduction in jitter and an improvement in overall sonic performance.

Speaking of clocks, the Hermes utilizes a superior-quality OCXOOven-Controlled Crystal Oscillator - a precision clock kept at a constant temperature in a heated enclosure, achieving sub-100ppb frequency stability for low-jitter digital audio applications., or Oven-Controlled Crystal Oscillator. This clock maintains a very stable temperature for the crystal oscillator, resulting in extremely precise clocking and minimal phase noise. This high-precision internal clock is a crucial foundation for its exceptional performance.

A critical element is the implementation of a FIFO buffer and reclockingRegenerating a digital audio signal's timing reference using a low-jitter local clock, effectively stripping the original clock's jitter from the data.. FIFO buffering isolates the incoming digital data from the timing of the source, minimizing the influence of jitter from the source device. The reclocking stageShort for soundstage; the perceived three-dimensional acoustic space of a stereo recording. Often used to describe headphone presentation specifically ("the Arya has a deep stage"). is used to generate a new, extremely accurate clock signal for the outgoing digital audio stream. This combination effectively eliminates jitter and ensures a solid digital signal is sent to your DAC.

Sound Quality

The Denafrips Hermes 12th DDC isn’t designed to impart a particular “color” or flavor to the audio. Its strength lies in what it reveals - the inherent character of your DAC, but elevated, refined, and turned up to 11. It’s less about adding something new and more about removing the obstacles that prevent your DAC from performing at its best.

It’s as if a veilA subjective loss of resolution and immediacy that makes recordings sound as if a thin curtain hangs between the listener and the performers. Can result from high distortion, limited bandwidth, or excessive damping. has been removed from the music, revealing a newfound clarity and focus. Details that were previously subtle or masked become more prominent, yet without any harshness or artificiality. This increased clarity extends across the entire frequency spectrum. It doesn’t boost up the treble range even the slightest bit. Though still, cymbals shimmer with realism, the subtle nuances of high-pitched vocals are rendered with exceptional clarity. The highs become more simply defined.

The bass frequencies also benefit significantly. The Hermes tightens up the low end, providing a more controlled and defined bass response. This isn’t about adding more bass - it’s about making the existing bass more precise and impactful. The low frequencies become less “sloppy” and more integrated with the rest of the sonic picture in a more time-accurate manner.

Soundstage and Imaging

The soundstageThe perceived three-dimensional acoustic space in a stereo recording - width beyond the speakers, depth front-to-back, and sometimes height information., that three-dimensional space where the music unfolds, expands with the Hermes in the chain - it’s a noticeable improvement. The soundstage becomes wider, deeper, and more immersive. Instruments are placed more securely within the sonic landscape, with less movement and uncertainty. The imagingThe ability to place individual instruments in precise, stable positions within the soundstage - good imaging means you can "point" to a violin in the mix., the ability to pinpoint the location of instruments, is also enhanced, contributing to a greater sense of realism.

Perhaps the most significant improvement is in the overall sense of naturalness and musicality. The Hermes seems to inject a sense of life and vitality into the digital audio stream. The music flows more effortlessly, with a greater sense of ease and dynamics. This makes for a more engaging and enjoyable listening experience, reducing listening fatigue and allowing you to connect with the music on a deeper level. It’s sort of like tube gear but with no colorationAny consistent deviation from accurate reproduction that imposes the system's own character on recordings; can be pleasant (euphonic) or fatiguing. or any downsides.

Conclusion

So… the Hermes 12th is not snake oil - it provides a clear improvement to the sound quality.