iFi audio ZEN Signature Set - DAC & Amp

Sunstealer

500+ Head-Fier
Forever Now
Pros: "Does what it says on the tin" for HD6 series
Detailed but not overly analytical
Balanced signal chain from DAC to transducer
Small footprint
Cons: Overpriced as a package
Benefits of more expensive power supplies debatable
Standard ZEN stack (especially with release of ZEN DAC V2) may be sufficient
IFi ZEN DAC&CAN 6XX Signature stack

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The ZEN stack was loaned to me by Ifi on request. Many thanks to Karina and Sebastien @iFi audio for facilitating this.

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Take a Look:
OnePlus 6 & Neutron Player
Zen Signature stack, Ifi 4.4mm balanced interconnect, 2x Ifi iPower X power supplies
Ifi Zen DAC, other 5V DC USB power supplies
Custom 4W copper Litz 4.4mm interconnect
Ifi IEMatch 2.5mm
Sennheiser HD58X, balanced silver cable
Audio Technica MSR7b, stock cables
Lime Ears Pneuma, stock single ended PW audio and custom balanced copper cables
TRI I3, balanced silver cable
Playlist made up of MP3, FLAC and DSD256 tracks.

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Running in the family:
The stack arrives in a combo box comprising of separate boxes for the DAC, CAN and interconnect. The stack follows the asymmetrical ovoid ZEN range design language but in a tasteful inky dark blue colourway which is both an improvement and contrast to the rather brutalist aluminium grey standard ZEN models. The casing finish is simultaneously smooth and rough to the touch, creating an unpleasant sensation through my fingertips. I have noticed this with other products both from Ifi and elsewhere. Clearly it is subjective but I find I cannot touch the casing for too long. The chamfered rotary volume pots have a smooth and pleasantly weighty action to them. Minute adjustments are possible with the touch of a finger.
The selector buttons on the front of the CAN have a slight wobble but this is the case for all ZEN models. It doesn’t really detract from the experience. All of the buttons apart from power have a tiny white LED next to them to indicate what has been selected. These are quite dim and are difficult to read, even in a dark room (which is where I do most of my listening). I realised this is because they are not in my direct horizontal line of sight. The Signature DAC is a standalone DAC only; the amp stage has been stripped out compared to the standard DAC.
I used both iPower Xs for the majority of the review period then swapped these out for various other power supplies for comparison - see the section marked “Turn it on”.

Are you hearing (what I hear?):
The sound from the stack is very much the house Ifi sound: balanced, musical and fun. This is my experience with several of Ifi’s other products. The main difference I hear is one of perceived warmth of tone. The Neo IDSD, to my recall, sounds a little cooler and more transparent than the stack whereas the Micro BL is warmer. The Ifi interconnect is a big beast, with very bulky connectors which are strangely weightless in the hand. There are 8 strands of what I interpret to be silver-plated copper (after deconstructing the marketing speak "OFHC continuous cast copper silver matrix”). I had a few problems with signal loss on rotating the jacks, even after careful cleaning, so swapped it out for my own 4 wire copper interconnect. No sonic change was heard with this or another SPC interconnect that I have. I could not hear any significant qualitative difference between the unbalanced RCA outputs and the balanced output, which to me shows the quality of both.

Physical Presence:
The HD6XX and Space settings have been specifically designed for the HD6XX but I figured they would do for the HD58X. I was pleasantly surprised with the HD6XX button - it adds a subbass kick, not a blanket bass warming but a focused pulse giving heft to kick drums particularly. I found it to be a useful option with brighter 80s synth pop and also with more modern music, e.g. Childish Gambino, Hotline Miami OST with the proviso that there is an intimation of subbass rather than a true presence. Certainly the setting moves the HD58X towards being a more useful all rounder (although by no means perfect).

The Xspace setting by itself sounded shrill and edgy. I would skip over this setting and activate both which sounded more integrated and synergistic. I did notice that I would often switch both on, listen for a while then switch them off and listen for longer. That’s not to say the enhancements weren’t euphonic, I just liked the way the HD58X sounded by themselves without any augmentation.

HD58X (Powermatch 12dB)
This is my first set of Senn overears. I must admit I wasn’t blown away by the soundstage focused into 3 regions to the front and sides (“3 blob sound”) with a lack of subbass and air. This was the case using the stock single ended cable through the single ended output but once I swapped this out for a balanced cable the blobs filled in and on earlier recordings (Level 42, 80 synth pop) the midrange and vocal performance really started to shine. I could clearly pick out Mark King’s ghost slaps, Phil Gould’s hi-hat runs and Boon Gould’s guitar fills. It even made the True Colours album easier to listen to (for me it sounds a lot drier and metallic than other Level 42 albums).

AT MSR7b (Powermatch 0-6dB)
There was some waterfall hiss which did not detract significantly from the music. These U-shaped phones were a surprise. Using other DAC/amps (e.g Fiio BTR5) there is plenty of bass and a warm musical tone. With the stack I didn’t really get much bass and needed to switch on the HD6XX function to get anything out of them. The treble was verging on harsh which again was a surprise. Not a good pairing, in my view.

Lime Ears Pneuma (IEMatch Ultra, bass switch off)
These mild U-shape hybrids sounded incredible with a balanced copper cable. Deep, focused bass, non-recessed mids and an articulate, sweet and airy treble. Great with the standard Zen DAC or stack. IEMatch was needed with both for best results. I didn’t need to use either the HD6XX or XSpace settings as the Pneuma has its own bass switch and the XSpace setting didn’t change the sound at all.

TRI I3 (IEmatch High or Powermatch 0dB):
These smooth U shaped tribrids do benefit from some power and here they present a warm tone with slightly flabby bass, even with a silver cable. No need for HD6XX or Xspace as the I3 has plenty at both ends already. From memory, the synergy with the NEO IDSD is far better than warmer members of the Ifi stable.

Turn it on:
The stack comes boxed with iPower X supplies and an Ifi interconnect. The interconnect is bundled “free” compared to the separate cost of the DAC, CAN and interconnect. Comparing the cost of the vanilla DAC and the Signature, there is a £120 difference (£130 versus £250). This extra cost is made up of new external and upgraded internal components and power supply. The difference between the 2 CANs is £80 with the same presumption. I can buy into the concept of upgraded internal components but I wasn’t sure how much of a difference the power supply would make so I experimented. I had 2 other USB power supplies, one from a Raspberry Pi (5V 2.5A) and my Oneplus USB block (5V 4A). I used an unbranded 5V 2A USB-DC cable.

Powering the stack with iPower Xs resulted in the least ground hum, that’s not in dispute. Using a mixture of iPower and other PSUs, there was least hum when the iPower was connected to the DAC. When powering using both the other 2 PSUs, there was more hum but whenever I plugged in my USB A OTG cable all hum disappeared. For all power supplies. So what use is the iPower if all the hum stops when connecting my source?

Two Solitudes:
I wanted to find out whether the upgraded components resulted in an audible improvement. I used the Pneuma and HD58X for this test. Compared to the standard DAC on phone power, there is a small but definite improvement in layering and depth to the soundstage when running off 5V DC power. Changing up to the iPower X didn’t improve that by any degree I could ascertain. Regardless of power supply, adding the Can Signature improved the bass focus and solidity. Swapping out the standard DAC for the Signature DAC did not result in any improvement in resolution or separation but I noticed a touch more warmth compared to the standard DAC.

Why are you leaving?
The ZEN Signature stack isn’t being disingenuous: it is explicitly designed and marketed to address some of the sonic deficiencies within the HD6 range. It definitely does that with grace and aplomb but I was equally as interested to discover if it could work for a range of transducers. I think the Signature stack does work for other IEMs (with an IEMatch) and headphones but careful matching is required for synergy. Like any other system, I suppose.

Judging by my experiments with the standard DAC, other power supplies and interconnects, the Signature models and stack combination package do not offer a significant sonic upgrade to the standard Zen stack. Admittedly I do not have a standard ZEN CAN to hand but I do not feel that it would make a significant enough difference to my opinion as it stands. Alternatively, the Signature stack without the added power supplies at a lower price could be a more attractive offering but I understand the marketing behind the decision to include them. I feel that the interconnect is overvalued and equal performance is obtainable elsewhere at a third of the price.

It’s Over:
If all you have are Sennheiser HD6 headphones and you have arrived at a place of serenity with that, the Signature stack is a holistic setup that works very well. If cost is a factor in your decision, a standard ZEN stack would be more than up to the task.

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iFi audio
iFi audio
Thanks :beerchug:
J
Jimmyblues1959
Thanks for the excellent review!
J
Jimmyblues1959
Just bought these and look forward to hearing them with my HD6XX when they arrive.
Thanks again for the excellent review!

Received these components recently and have been using the Zen Dac Signature and Zen Can HD6XX with my Sennheiser HD6XX. I find them to be an excellent sonic match! 😊

McCol

Headphoneus Supremus
Pros: ZEN DAC signature
Design & Construction
Balanced output
Value (Included accessories)
MQA support

ZEN Can Signature
Design & Construction
Value
Custom EQ makes a difference
Sounds excellent with other headphones as well
Plenty of power to drive most headphones

Inclusion of ifi ipower X power supplies and 4.4mm to 4.4mm cable for connecting the 2 units.
Cons: DAC has no power switch, only switches of when computer shuts down.
About me:

I've been using various DAP's, portable DAC's/Amps and earphones for around 20 years, over the last 2 years I've been exploring full sized headphones. Grado's and Sennhesier have been my headphones of choice so far paired with an iFi-Audio Black label Idsd micro DAC/Amp.

This is my first foray into a desktop solution.

Disclaimer - iFi-Audio sent me this pack in exchange for my honest opinion, pack will be bought by me if I decide to keep.

Specs:

Full technical specs links and product pages

https://ifi-audio.com/products/zen-can-signature-6xx/

https://ifi-audio.com/products/zen-dac-signature/

Gear used:

iMac 27 - Source for connection.
Sennheiser HD660s
Grado Hemp
Etymotic er4sr
Custom Art FIBAE 4 custom earphones

What's in the box?:

iFi-Audio have put together a very nice package with this Zen Signature edition pack. You get both the Zen Signature DAC and the Zen Can Signature 6xx with ipower supplies for both, but I guess the deal breaker is the inclusion of the 4.4mm balanced cable which normally retails for around £90

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Each unit also comes with RCA cables, the Zen Dac Signature also comes supplied with a USB-A cable for connecting the DAC to PC/MAC

Build Quality:

A quick word on the design and build. The Zen duo here are nothing short of excellent for both their design and build quality. The materials used feel really good, brushed metal effect on the front, all buttons and dials feel sturdy.

Set Up:

Set up is pretty straight forward, connecting DAC to Mac with supplied cable, DAC to AMP with suppled 4.4mm to 4.4mm balanced (cable feels excellent quality). Sennheiser 660s to 4.4mm balanced output on the Zen Can. DAC is powered automatically by the Mac, no power switch, this might be a liitle bug bear for some but no issue here. Zen Can does have a power button on the front.
I left the volume set to fixed on the Dac, the volume is then controlled via the Zen Can only.

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Sound:

I used a selection of tracks and albums to try this combo, most of my music is indie/alternative guitar based however I also listen to quite a selection of electronic music.

Most of my testing was done using the Sennheiser 660s and for the most part I used the ActiveEQ option for the 6xx


Main albums used over a two week period were:

David Bowie - Ziggy Stardust, Low and Station to Station
The Smiths - The Queen is Dead and Meat is Murder
Mogwai - Come on Die Young and As the Love Continues
Pet Shop Boys - Introspective
New Order - Retro (5cd edition)
The Wedding Present - Seamonsters
British Sea Power - The Decline of BSP and Do You Like Rock Music?
The Velvet Underground - White Light/White Heat
The Fall - Various albums

Bass - The bass is well controlled from the Zen Dac, it is well defined and layered in it's presentation, the bass response never feels like it is bleeding into other frequencies. It has good impact and when the track requires bass the Zen delivers. I'd say that overall the bass has a slightly warm feel to it but I like this and feel it benefits the sound overall, stops it sounding cold and clinical.

Mids - The midrange is smooth and detailed without ever sounding congested, vocals are delivered smoothly and not too far forward in the mix, there is a certain laid back feel to the mids, not warm but reminds a little of some the music systems I experienced as a youngster in the late mid 80's at family members houses, mainly Sony equipment.

Highs - Similar to the mids in regards to the fact that they are smooth and detailed however never aggressive in their presentation, snares and cymbals have a snap and presence of the track requires. Guitars in the Mogwai albums have the crunch that they are meant to have without overpowering other aspects of the sound. No treble peaks present on any of my tracks.

Pairings:

Sennheiser 660s - This duo from iFi was designed in part to be used with the 6xx series from Drop, however there was also a reported benefit to other models in the 600 range.
I tried most tracks with some A/B ing between the two different modes, the 6xx option certainly changers the sound of the headphones to a degree, to my ears it lifts the bass slightly, makes it more defined and refined than when the ActiveEQ is not employed. Don't get me wrong the headphones sound great anyway however the EQ does seem to enhance them a little more, it's not a night and day difference, more of a subtle change to the bass and maybe just a slight uplift of the treble response.
Other than that the combo of the two gives an excellent detailed yet laid back musical sound which I've found myself lost in for hours with no fatigue. Bowie's Ziggy Stardust album on Tidal Masters sounds blissful with this combo, detailed yet as already mentioned warm and non fatiguing. However when required on tracks such as Mogwai Fear Satan by Mogwai it has all the energy and precision required for the passages when the guitars kick following a quiet passage.


Grado Hemp - The Grado Hemp have a slightly warmer tone compared to my Grado 325's however they do still have that Grado treble sound to them, they actually pair really well with the Zen Dac/Can Signature combo. The 6xx EQ probably doesn't work quite as well on them however with the option off or using the Xspace EQ option they pair really well. The Xspace option is described as giving a more spacious and speaker like experience. It certainly gives the ,music more space with the Grado's.

I also tried a couple of IEM's with the combo which wouldn't be my intended use however this changed when trying my Etymotic er4sr. Over the years I've only ever really used the Ety's with DAP's or portable map solutions. I was quite shocked at the difference the power the Zen Can gave to the Ety's, they retain their lovely presentation however the depth and soundstage achieved with the Zen Can means that I've been using these quite a lot over the last few days, it has given my Ety's a new lease of life.

Comparisons:

These are only brief comparisons as I don't have a comparable desktop system to compare.

Ibasso DX300 - The Ibasso is a fantastic piece of hardware for using on a more portable basis, the DAC implementation of quad Cirrus gives the DX300 a very analogue sound that not dissimilar to the Zen combo is both warm and detailed, I'd say that the DX300 is maybe marginally more detailed in the highs and lows but they are very close. I think the Burr-Brown Dac chips of the Zen Dac produce a similar sound. To my ears the mids sound smoother on the Zen Dac however the DX is only a few hours into it's burn in time so this may change. Power wise the Zen Can provides more power which you would expect form a dedicated Amp. It's worth bearing in mind that this isn't really a fair comparison as they are totally products aimed at different aspects of the market, there is also quite a price gap between the two. the DX300 is currently around £1100.

iFi-Audio Idsd Black Label - This is probably a fairer comparison although the idsd is more of a portable/transportable model, however they both share Burr-Brown DAC's. I'm not sure if they are same DAC's but the sound is similar between the two. I'd say that the Zen DAC/Can combo is more detailed and more musical in it's presentation but not by much.

Conclusion:

I haven't really gone into specific detail on the separate components on offer here from iFi-Audio. My aim was to give thoughts on the combo of the two units. This is my first foray into desktop equipment for my headphones/earphones specifically the Sennheiser 660s.

Overall I feel this an excellent pack from iFi-Audio. The separate units retail for £249.99, so a total of £500 and that's without the 4.4mm cable. The £500 for the pack means a saving of around £90 is made on buying separate. The included iPower X supplies with the pack also add to the value.

From a sonic viewpoint, I am pleasantly surprised at how much of a difference this combo has made to my listening experience, the DAC section of the combo is detailed yet warm and musical, very non fatiguing. The amplifier section of the Zen Can is what I'm really impressed with, the power it gives to drive my Etymotic earphones and some of my high Ohm rated earbuds has added a new level to music listening.
Last edited:
TheAristotle
TheAristotle
Is the DAC the same as the new V2 or the original?
J
Jimmyblues1959
Excellent review!
J
Jimmyblues1959
Just bought these!
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