Review: Sennheiser HDV 820 Reference Headphone Amplifier

In addition to an explicitly high-quality analog section, which, in contrast to the headphone amplifier of the Orpheus HE 1, uses a purely transistorized circuit, the HDV 820 also offers a high-quality D / A converter with USB 2.0 computer connection. With a price tag of 2,399 euros, it is therefore also above the HDVA 600 model, which has since been discontinued, purely analogue.

For the signal, you can choose between analog unbalanced (cinch), balanced (XLR) and the digital sources USB 2.0, S / PDIF optical and S / PDIF coaxial. The ESS-SABRE32 D / A converter is used on the digital side, offering resolutions up to 32 bits, sampling frequencies up to 384 kHz and bitstreams up to DSD256 (12.3 MHz). If a bitstream format is detected, the associated status LED lights up on the front.

There is a rear level control for the unbalanced input, which is set with a screwdriver and allows fine adjustment. As in the HDVA 600, there are XLR outputs as a special feature, with which the test device becomes a real preamplifier that can also feed active monitors or power amplifiers.

Technical Data

Features and processing

With a live weight of over two kilograms, Sennheiser’s new pupil leaves no doubt when unpacking that you want to box in the heavyweight class in every respect. In general, the powerful, yet elegant appearance of our test subject is appealing. The housing made of black anodized aluminum is flawlessly processed in the usual Sennheiser quality and offers its high-quality interior an appropriate home. As already indicated, there is a lot more hidden inside than you might initially think. In addition to its main function as a digital headphone amplifier, the Sennheiser HDV 820 is also a high-quality DAC (D / A converter) that can be connected directly to the PC or Mac. And to top it all, it can also serve as a preamplifier.

An ESS Sabre32 chip is used as the converter, which, thanks to its excellent properties, is also very popular in high-end products in the pro audio sector. According to its name, it is 32-bit capable and supports sample rates of up to 384 kilohertz (kHz). In addition to the de facto standard PCM, DSD formats up to DSD256 can also be read. The appropriate software is required. In order to achieve the greatest possible channel separation and generally to minimize the influence of interference, the entire signal path of the luxury device is symmetrical. No effort is spared here to achieve the best possible results.

This idea is also consistently developed further in terms of connections and so there are even two options for headphones that are designed to use balanced connections. On the front there is a 4-pin XLR connection as well as two 4.4 millimeter Pentaconn sockets. In addition, the amplifier has both XLR inputs and outputs. With the appropriate peripherals, the complete signal flow can really be kept symmetrical. The outputs can be used to control stereo power amplifiers, for example, but also active loudspeakers. The HDV 820 then effectively acts as a preamplifier.

If you use such a setup in combination with the USB interface and a computer as a player, you get a modern and compact stereo system. Speaking of USB. As almost always, Mac users do not need additional drivers. With Windows systems, however, there is no getting around it. Instead of just referring you to the Internet, Sennheiser includes the installer and the manual on a USB stick. Exemplary! The same applies to the use of an internal power supply unit in combination with the supplied IEC cable. The only question that remains is why wasn’t a suitable USB cable included? But most people probably have enough of them at home anyway.

Practice

Apart from source selection and level control, there is nothing to be adjusted on the HDV 820. Conceptually, this is about pure musical enjoyment. Accordingly, I do not miss any display of the level or the detected resolution on the device. On the other hand, I would have been happy about remote control.

I consider the balanced XLR outputs to be a sensible added value, as the HDV 820 can take on the role of a preamplifier and central D / A converter. This is just as useful for a listening position as it is in a professional environment, for example if you want to work alternately with headphones or speakers at a workplace. I find the fixed volume control for this output impractical. I would have liked at least a mute button for the XLR output.

The USB connection takes place under macOS with class-compliant drivers, while the Windows drivers are supplied on a USB stick. The HDV 820 can be addressed via a system driver or via the professional ASIO protocol from studio software. Firmware updates can also be downloaded to the device via USB.

The maximum output power depends on the output socket used and the resistance of the headphones. It is around 480 mW with a 600 Ω load at the XLR-4 output. But don’t worry: the level reserves are completely sufficient even with quieter headphones. There is also the option of symmetrical operation, which significantly increases the output level again.

Sound

Like any good amplifier, the HDV 820 has the task of bringing the source to the listener in an unadorned, accurate and fully controlled manner at the desired volume. The review sample does exactly that, with an exemplary low noise level. It actually sounds good at any volume. In the end, so good that you can enjoy higher levels without distortion and quickly turn the volume control up too far – a phenomenon of high-quality component combinations.

Basically, the HDV 820 naturally works with almost any wired headphone, but according to the manufacturer it is optimized for headphones with high impedances. The real added value of such a construction is particularly evident in combination with explicitly high-quality headphones – in the sense of a consistently audiophile playback chain, which is almost self-evident, even in view of the price.

In combination with the HD 800 S and HD 820, the amplifier provides sufficient level reserves and is otherwise exactly as you would expect from such a great playback chain. In high resolution and without any whitewashing, the HDV 820 opens up a glimpse into the quality of each mix / sound source and its character in terms of level ratios, frequency coordination, dynamics as well as stereo positioning and space.

The basic trend is that the Sennheiser product is quickly and analytically coordinated. It deliberately does not introduce any basic warmth into the reproduction and is in no way loud in the bass, but always controlled. At the other end of the frequency spectrum, the amplifier is linear, well beyond the audible range, and is accordingly open and airy.

He reproduced the multilayered mixes of Steven Wilson’s current CD (The Future Bites) in an impressive way. The finest details, three-dimensionality and precision go hand in hand with a complete frequency response and perfectly understandable dynamics. In addition to a meticulously structured stereo panorama, the HDV 820 can also convey a remarkable closeness. And actually it feels like you’re sitting together in the recording room with Tina Dico while she is performing “The Woman Downstairs”.

Whether modern metal sound, orchestral works, intimate singer / songwriter compositions or bass thunderstorms from the dancehall genre – the HDV 820 always remains calm but extremely attentive. In addition, differences between headphones become apparent just as quickly on this amplifier as between mixes. You almost automatically approach the sound assessment a good deal more critically. Sometimes it sounds a bit too slim or slightly too bright, then pleasantly warm and round or even pot-shaped and maybe even throbbing. Only in the bass do the results never fly around your ears uninvited – provided a good mix. These are all characteristics that the professional warehouse also appreciates. Supplied with symmetrical or digital signals, you have an exquisite alternative monitoring system for the mix, the cut or real premium comfort for the prominent speaker. By the way: The symmetrical operation is not necessarily superior in terms of sound, but it does deliver more level.

Sennheiser HDV 820 Amplifier – Conclusion

With the Sennheiser HDV 820, Sennheiser is pursuing a straightforward and audiophile concept. The product is a coherent consequence of the manufacturer’s participation in the market for high-quality headphones, which it makes sense to provide with correspondingly outstanding and coordinated amplifiers. The prices in this category are undoubtedly high. However, this also applies in full to the sound performance, which is actually flawless and ensures the highest level of pleasure or an incorruptible reason for evaluation in the professional field. The HDV 820 is aimed at the group of sound connoisseurs who demand the best possible performance from their playback chain. As is well known, the technical effort for the last percent of performance increases significantly, which is also expressed in a higher price.