ifi ZEN CAN Audio Super-Affordable Headphone Amp User Guide
- June 6, 2024
- ifi
Table of Contents
ZEN CAN
User Guide
Introducing the ZEN CAN
The TL; DR
The fire audio ZEN CAN is a fully symmetric dual-mono headphone amp based on
our Pro iCAN’s circuit, with latest 4.4mm Pentagon connections on input and
output, and an in-built 3D and XBass analog signal circuits.
iFi audio ZEN CAN versus ZEN CAN
Signature 6XX
The ZEN CAN Signature 6XX amp launched recently in the US market via the DROP
platform was tailored specifically for Sennheiser 6XX headphones, whereas the
ZEN CAN amp was designed to drive ALL headphones. 
Connections
Technologies
Topology
iFi audio ZEN CAN’s amplification circuit is the same as used in Pro iCAN. It
features a balanced discrete Class-A output buffer combined with a J-FET Op-
Amp (OV2637A). Its FET input doesn’t load volume control, which means
exceptionally low distortion/noise, whereas low impedance feedback enhances
overall performance and avoids resistor noise. The ZEN CAN’s internal amp also
fully protects itself and headphones from overloads/shorts. Its four-step
output gain factor is set at +6dB.
XBass and 3D
XBass adds back lost bass for headphones (especially open-backed), whereas 3D
provides in-room speaker ‘ listening sensation for them. Both these features
are based on fully analog circuits.
Power supply
The ZEN CAN’s power supply is based on Pro iCAN’s stealth mode voltage
conversion circuit with heavy LC (resistor-inductor) filtering to separate the
audio path from the internal PSU. 4,000uF capacitance acts as a huge ‘power
reservoir’ for short transient (i.e. music) signals.
Inputs
The Fi audio ZEN CAN features two inputs; single-ended RCA (1M Ohm) and
balanced 4.4mm (24k Ohm). The ZEN CAN’s dedicated input stage adjusts its
input levels to match connected sources, but at the same time it avoids
loading them and allows for constant Class A operation and lowest distortion.
MCU optimizations
To keep noise contamination to an absolute minimum, the ZEN CAN’s MCU (a
microcontroller unit to manage key functions of the product) and LEDs are in
‘wake mode’ only when actioned. Otherwise, they’re put into ‘sleep mode’, even
during listening to music. All switches inside the product are FET-based for
full sonic transparency, ability to handle enormously high peak signals, and
distortion/noise levels below Audio Precision 2’s measurements.
Premium components inside
The iFi audio ZEN CAN features the following boutique parts:
Panasonic ECPU
Each ECPU capacitor consists of ~3,500 >0.5μm thick dielectric layers and
boasts class-leading Equivalent Series Resistance (ESR), low impedance,
frequency stability, and vanishingly low distortion. A total of 6 pieces are
used.
Class 1 ceramic TDK C0G
These highly stable low-loss capacitors are used in our LC circuit application
to further reduce capacitor-induced distortion.
iFi/AMR ‘OV’ ICs
Four independent OV2637A J-FET op-amps are used in the ZEN CAN’s internal
‘folded cascade design. Each IC is based on HCOFC copper lead-frames, 4N gold
bond-wire, and features wide bandwidth, extremely low noise and distortion
(0.0001%).
Texas Instruments ICs
These low-noise/distortion parts offer great unity-gain bandwidth, high output
drive capability, Common-mode and Power Supply Rejection Ratios above 100 dB,
wide maximum-output-swing bandwidth, and high slew rate.
BiCMOS technology
To further reduce noise, and have an excellent transient response and PSRR
performance (rejection of power supply noise), the iFi audio ZEN CAN features
Bipolar CMOS (BiCMOS) semiconductor technology, which integrates two separate
semiconductor types and makes the best of them.
TOCOS potentiometer
Tokyo Cosmos Electric Co. (TOCOS) multi-track potentiometer provides close
channel matching tolerance for optimal performance, even at quiet listening
levels.
SMT (Surface Mount Technology)
The SMT assembly eliminates load-outs and terminations as possible sources of
noise and distortion. It also dramatically improves most mounted components’
performance by minimizing parasitic elements created by manual soldering.
Why balanced?
In a single-ended three-wire headphone connection, the ground is shared
between left and right channels. That’s why both channels’ wires and
connectors have extra resistance, which causes unwanted crosstalk between
them. A four-wire balanced connection eliminates this issue completely.
The iFi audio ZEN CAN’s balanced circuitry completely separates both channels,
and its line inputs will work with balanced output sources and professional
equipment. It features a Pentaconn connector type because of its high-quality
build and low contact resistance.
XBass
Many open-backed headphones have sub-100Hz bass invariably rolled off due to
their open ear cups which let out all frequencies
instead of trapping and redirecting them back to our ears, just as closed
headphones with good bass response do. Open-backed products also don’t cup up
the midrange as their closed types, hence the former is famed for natural
sound, but the bass extension was never a strong suit.
The ZEN CAN’s XBass equalization benefits
all headphone types, consists of active and passive components, and its
frequency response curve corrects low-end response problems with precision and
exclusively in the analog domain. The correction process itself shapes the
output without altering the midrange, worsening SNR, or increasing distortion.
The result moves any headphones closer to a neutral presentation with less
midrange over-emphasis, with a full and natural bass and no veil over the
treble.
3D for Headphones
In most cases, music recordings are mixed and mastered for speakers. Played
through headphones it results in a sound-field perspective of playback inside
our heads, which leads to an unnatural, fatiguing and stressful listening
experience.
If heard by one ear only, sounds from the left and right stage result in extreme stereo separation that shrinks the perceived soundstage width to right over or even in-between the ears. Distance cues intended by the inter-ear delay of even sounds that do make it to both ears are also destroyed. Using a suitable correction system, the music can be relocated outside our heads and projected in front of us spatially wide and high, to introduce a listening experience comparable to what a good pair of speakers do.
iFi audio ZEN CAN incorporates 3D analog filtering technology that:
- creates stereo image truly out of your head, with spatially realistic depth and width
- doesn’t introduce any coloration or resolution loss
- is based solely on analog circuitry (no DSP!)
- works regardless of a listener’s anatomy and hearing.
Components
FAQs
I see three inputs on the ZEN CAN’s rear. Which one does what?
Those inputs are balanced 4.4mm Pentaconn, a single-ended 3.5mm, and a single-
ended RCA. If your DAC has balanced outputs, then ZEN DAC’s balanced input is
the one to use. Otherwise, each ZEN DAC’s single-ended input will do just
fine.
Why does the ZEN CAN feature only one output?
To take full advantage of ZEN CAN’s balanced architecture, it features only a
4.4mm Pentaconn output. What type of power
supply will work with the ZEN CAN?
Any external power supply able to provide DC 5V/2.5A will work. For optimal
results please use our iPower X/iPower. If USB outputs in your computer/laptop
are within listed specs, it’s possible to power the ZEN CAN from these ports
as well, and thus avoid the usage of an external power supply.
It’s worth knowing that the ZEN CAN appreciates more than 2.5A, and can handle
up to 4A peaks.
I see no switch to have the ZEN CAN’s balanced output fixed. Why?
The ZEN CAN was designed to operate as a high-quality headphone amplifier, but
also as a fully balanced preamplifier, which is why its balanced output is
regulated.
How do I use the ZEN CAN’s inputs?
Please connect a cable of choice from your DAC to the ZEN CAN’s suitable
input, and engage via the input selector button on the product’s front.
Single-ended cables will work with 3.5mm and RCA inputs, whereas a balanced
cable will work with 4.4mm Pentaconn input.
Can all three inputs be connected at the same time?
You can have cables connected into each ZEN CAN’s input, but only one can be
active. How do I know which of the ZEN
CAN’s inputs is currently engaged?
All available inputs are labeled respectively and can be seen just below the
input selection button on the ZEN CAN’s front. A currently engaged input will
be highlighted by a white LED.
Can I cycle between inputs while the product is powered?
Yes, you can.
What does the gain button do?
It matches the headphone amplifier gain to the headphone. Headphones have very
widely varying sensitivity, so a good match in gain is important, too low gain
and headphones will not play loud enough, too much gain and there will be
excessive noise and distortion with very little usable volume range.
How do I know which gain setting is right for me?
Use the lowest gain setting that gives you a good comfortable listening level
with the volume control at around 12 o’clock. If you can’t go higher in volume
as music becomes too loud before reaching 12 o’clock at the lowest gain
setting, you may want to test the iFi iEMatch product to see if this helps to
match your headphones better to the ZEN CAN’s headphone output.
How are the ZEN CAN’s two headphone outputs different?
The ZEN CAN’s 6.3mm socket is meant to be used with unbalanced headphone
cables, whereas its 4.4mm Pentaconn headphone output will work with balanced
cables.
What happens when a DAC is connected with the ZEN CAN via RCA cable, but I
use the product’s 4.4mm headphone socket?
The ZEN CAN will convert the unbalanced input into a balanced signal and drive
connected headphones in balanced mode.
Can I have two headphones connected at the same time?
It is not recommended.
What does the XBass/3D button do?
This button cycles between two analog features inside of the ZEN CAN. Please
see https://bit.ly/3DHolographic and
https://bit.ly/TotallyAddictedToBass
Can both filters be applied at the same time?
Yes, they can. Simply press the 3D/XBass button until both white LEDs are on.
Can ZEN be powered all the time?
Yes, it can. But if not used it should be powered off. Let’s go a bit easier
on the planet!
What kind of headphones can I use with the ZEN CAN?
Several exceptions and electrostatic products aside, the ZEN CAN’s internal
amplifier circuit is powerful enough to effortlessly drive the vast majority
of headphones available on the market.
What kind of cables do I need to get the best out of the ZEN CAN?
The ZEN CAN works well with standard RCA cables, but to get the very best out
of it, you’ll need to use the 4.4mm Pentaconn input on its rear.
Upon connecting everything there is no sound. What to do?
- Check all connections, power, input, headphone.
- Make sure the ZEN CAN is turned on (input & gain LEDs will light up).
- Make sure the correct input is selected (check number on the back).
- Make sure music is actually being played via your source.
Lifestyle desktop systems
Standalone
- Analog x 3 sources
- BALANCED 4.4mm > 4.4mm line out
- BALANCED 4.4mm headphones
- SE 6.3mm headphones
With ZEN DAC
- DAC input for digital
- Analog x 2 extra sources
- BALANCED 4.4mm > 4.4mm interconnect
Lifestyle desktop systems
With ZEN Blue
- Bluetooth streamer input
- Analogue x 2 extra sources
- BALANCED 4.4mm > 4.4mm interconnect
- BALANCED 4.4mm > Pre amp Output
With ZEN Phono
- Creates a lifestyle vinyl system
- Compact desktop headphone system
- Future expansion with active speakers
- BALANCED 4.4mm > Pre amp output
- MM & MC compatible RIAA Phono input
- BALANCED 4.4mm >4.4mm interconnect
Lifestyle desktop systems
With ZEN DAC & ZEN Blue
Creates a ‘semi-pro BALANCED system for under £500
- Bluetooth streamer input
- DAC input for Hi-Res 44.1/16 – 192/24 and DXD
- Analogue x 2 extra sources
- BALANCED 4.4mm > 4.4mm interconnect
- BALANCED 4.4mm headphone output
- 6.3mm Pro gauge headphone output
- BALANCED 4.4mm > Pre amp Output
- 3D for non-fatiguing extended listening
Specifications
Inputs| 4.4mm Pentacon BAL
RCA L/R Socket SE
3.5mm Jack SE| 4.0V nominal @ 0dBFS, 24 kOhm Zin
2.0V nominal @ 0dBFS, 1 MegOhm Zin
1.0V nominal @ 0dBFS, 1 MegOhm Zin
---|---|---
Max Output| Balanced SE| >15.1V/385 mW (@ 600 Ohm)
11.0V/1890 mW (@ 64 Ohm)
7.6V/196 mW (@ 300 Ohm)
7.2V/1600 mW (@ 32 Ohm)
THD & N| Balanced| < 0.0007% (4V out, 600 Ohm, 1kHz)
SE| <0.006% (@ 100 mW/1.27V 16 Ohm)
SNR| Balanced| >120dBA (@ 15.2V)
SE| >118dBA (@ 7.6V)
Max Input| Balanced| 7.4V RMS
RCA| 3.8V RMS
3.5mm| 1.92V RMS
Gain| | 0dB, 6dB, 12dB and 18dB
Frequency Response
| | 20Hz – 20kHz (+0dB / -0.03dB)
Power consumption| No Signal| ~5W
| Max Signal| ~13W
Input voltage| | DC 5V/2.5A
AC 100 -240V
50/60Hz
Dimensions| | 158 x117 x35 mm
6.2″ x 4.6″ x 1.4″
Net weight| | 515g
1.14 Ibs
ifi-audio.com/products/zen-can
References
- ZEN CAN by iFi audio Super-affordable headphone amp from iFi audio
- bit.ly/3DHolographic
- bit.ly/TotallyAddictedToBass