iFi ZEN Signature Set HFM Review

iFi’s Signature products originated from a handful of limited run models, which had filter options specifically tuned for certain headphones. Now iFi Audio has begun doing larger releases for their Signature series, starting with the Signature 6XX models and now continuing with the Signature HFM. The ZEN Signature Set HFM is designed for use with HIFIMAN headphones and includes the ZEN DAC Signature V2 and ZEN CAN Signature HFM (along with a nice balanced 4.4mm interconnect cable). Let’s take a look and see if these really do bring out the best in HIFIMAN’s headphones.

Build and Design

The construction of the ZEN Signature line is essentially the same as the standard ZEN Series, but you get an exclusive dark blue and black color scheme that looks fantastic. If you’re not familiar with the ZEN Series, you get a could-almost-be-portable sized device in a shape that, when stacked, evokes the look of a pagoda. The chassis is aluminum and quite sturdy.

iFi ZEN Signature Set

One of the shared design elements across the ZEN lineup is the large analog volume knob centered in the front of most of the units. The button design is also shared across models (at least the ones that have buttons) and the buttons have a nice tactile click.

With the ZEN Signature Set you get the full retail package of both the ZEN DAC Signature V2 and ZEN CAN Signature HFM. The DAC comes with a USB-B cable, RCA cables, and an iPower 5V. The CAN comes with similar RCA cables, a 3.5mm to 6.3mm adapter, and the same iPower 5V power supply. And as an added bonus, a 4.4mm balanced cable to connect them together.

Using the ZEN Signature Set

With the two components combined, there’s a lot to cover in terms of the connectivity and other options you have. While these devices are bundled together as a perfect pair, you may have a DAC or amp that you’d rather pair up with either unit, and both pieces of the Signature Set can work with a number of devices using standard connections.

The ZEN DAC Signature V2 only accepts input via USB, and it can output through RCA for single-ended or 4.4mm for balanced.There’s a switch on the back labeled “Fixed/Variable” which controls whether the output functions as a simple fixed line out with no volume control, or whether the ZEN DAC is functioning as a preamp with variable volume control.

iFi ZEN Signature Set

The ZEN CAN Signature HFM has a few more input output options. As an amplifier, it only accepts analog inputs, so you can receive input via RCA, 3.5mm cable, or 4.4mm balanced. For outputs, there’s a balanced 4.4mm line out on the back, with 6.3mm single-ended and and 4.4mm balanced headphone outputs on the front.

In addition to the volume knob, the ZEN CAN Signature HFM has a number of options for tuning your sound. First off is the PowerMatch setting, which is essentially the gain level. There are four options ranging from 0dB to 18dB that you can cycle through. The goal is to find the gain setting that lets you set the volume knob close to 50% for a comfortable listening level. You also have the option to activate the HFM filter and XSpace feature. XSpace is iFi’s “analog headphone spatializer” which is designed to enhance the sensation of width in the soundstage. The HFM filter is designed with the HIFIMAN house sound in mind, and it bolsters the subbass, makes some adjustments in the upper mids, and helps tame some of the treble peaks to help tweak the sound signature to bring it closer to what many consider to be an ideal headphone tuning.

iFi ZEN Signature HFM EQ

The Sound

Taken together or separately, the ZEN DAC Signature V2 and ZEN CAN Signature HFM have a smooth, neutral delivery with a level of detail that’s a step above the rest of the ZEN lineup. The ZEN DAC Signature V2 in particular has a notably tighter response and a greater feeling of detail and definition in it’s output. The Signature V2’s reference-like response and excellent detail make it a strong contender in the $300 range for a DAC, and provides an option from iFi with less notable warmth than many of their other DACs.

The ZEN CAN Signature HFM trades the somewhat aggressive, somewhat bassy – and definitely fun – output of the original ZEN CAN for a more neutral sound, with a little less fun and a lot more detail. It’s still a powerhouse headphone amp that can coax plenty of visceral, physical response from your headphones, but now it gives you that energy with a more accurate, balanced overall delivery. There’s a clear improvement in the soundstage as well – even without the XSpace turned on.

iFi ZEN Signature Set HFM

Their sound and specs make the ZEN Signature Set HFM a good buy to use with any headphones, but for owners of HIFIMAN headphones – particularly those in the under $1000 range – the ZEN DAC Signature HFM is indeed very well tuned for getting the most performance possible out of your headphones. We’ve already discussed the specifics of what the HFM filter does, so next we’ll look at how it interacts with different headphones.

As a whole, the HE400se matches quite well with the ZEN Signature Set HFM, and it particularly benefits from the HFM and XSpace functions. The HFM filter was very clearly designed with the HIFIMAN HE400se and Sundara in mind. Their marketing materials even use something that looks a lot like the FR curve from the HE400 to demonstrate the effect of the HFM filter. While the XSpace hits the HE400se’s soundstage, adding some much needed width, the HFM filter fills in the “missing” subbass and tames any tendency towards brightness in the highs. Put it all together and you have incredible performance out of $149 headphones.

Even without any of the special features or adjustments, the ZEN Signature Set HFM makes a great pairing with the HIFIMAN Arya. The balanced, powerful response helps bring the Arya’s detail, tight linear bass, and massive soundstage to life. If you prefer to leave Arya’s tuning untouched, you can certainly do that.

iFi ZEN Signature Set HFM Arya

On the other hand, if you want just a little more low end or find the Arya’s highs somewhat fatiguing, the HFM filter adds some depth and rumble to the Arya’s bass, and provides a subtle cut to some of the peaks in the highs that might be problematic for certain genres. The XSpace filter is less impactful and doesn’t have a strong effect on the Arya’s soundstage – at least not to the degree that it impacts the HE400se.

Comparison: Burson Playmate 2

The ZEN Signature Set being a step up in price from the regular ZEN lineup also means that it has some stronger competition. The Burson Playmate 2 is one of the best DAC/Amp combos under $600, and it makes a good comparison with the ZEN Signature as there’s a lot of contrast between the two.

First off, in terms of size and form factor, the ZEN Signature Set leaves a smaller footprint on your desk, and there’s definitely a strong aesthetic difference between the two. While the Signature Set has a smooth design that evokes a more relaxing atmosphere, the Playmate 2 wouldn’t look out of place in the cockpit of a vintage fighter jet. In terms of overall configuration convenience, the Playmate 2 has less wires and connections to deal with by virtue of being a combo, but of course there are advantages to having individual components as well.

Burson Playmate 2

While aspects of the Playmate 2 look simpler than the ZEN Set, there’s actually a bit of complexity just under the surface. For one, rather than simply having something like the HFM and XSpace options, it has close to a dozen DAC filters, as well as a “Emphasis” and DPLL (noise and jitter reduction) options. However, while HFM and XSpace are clearly documented and defined, Burson’s filters operate on more of a “use your ears and experiment” philosophy.

In terms of the sound, the Playmate 2 has a more aggressive, slightly bright tone with an incredible, fast, dynamic response. While the ZEN Signature Set has a more neutral, relaxed sound. While the power output is fairly close between the two, the Playmate 2 is more energetic and just feels like it hits a little harder overall. Both combos provide good a solid 3D image with a good sized soundstage and accurate imaging for the price, but there’s a slight edge for the Playmate 2, as even with the XSpace on, the ZEN Signature Set doesn’t have the same feeling of realism in the soundstage as the Playmate 2.

I’d say there are three key differences between the two. The first being contrast between the faster, more dynamic response of the Playmate and the more balanced subdued output of the ZEN Signature Set. Another being the simplicity of the ZEN Signature Set vs. the higher level of configuration and customization provided by the Playmate 2, from the filter selection to the ability to easily change out op-amps to change the sound of the device. The last key difference is the tuning of the two, with the Playmate leaning slightly bright – in a way that can push headphones like the HE400se into the more fatigue range – and the ZEN Signature Set having a more neutral tone.

The Bottom Line

The ZEN DAC Signature V2 and ZEN CAN Signature HFM are a great pair, and a clear upgrade to the devices in the standard ZEN line.The ZEN DAC Signature V2 is well designed to work with any amp, and while the HFM filter on the ZEN CAN Signature HFM is specifically tuned to get the best out of HIFIMAN headphones, every other aspect of the set makes it a solid buy in the price range no matter what headphones you’re using.