In just a few short months, iFi’s first ZEN Series products – the ZEN Blue and ZEN DAC – have established themselves in the crowded $200 desktop DAC category, making high-performance audio more accessible. Now, iFi expands the product range with the ZEN CAN – an all-analog headphone amplifier in the same compact aluminum chassis and offering the same exceptional value-for-money.
With an RRP of just US$149 (€165), the ZEN CAN offers features usually reserved for high-end headphone amps at many times the price. The ability to drive tough headphone loads, the balanced circuit design, the vanishingly low levels of distortion and versatile sonic tailoring options to optimize performance are all highly unusual at such an eminently affordable price tag. By combining them in one package, iFi believes they are once again pushing the envelope of affordable desktop audio.
As an all-analog headphone amp, the ZEN CAN has no digital input of any kind, USB or otherwise. It connects to any audio source with an analog output, such as the headphone output from a DAP (Digital Audio Player), a laptop, a tablet or a smartphone, or the RCA outputs from, say, a CD player or phono stage. It could be paired with the ZEN Blue to add Bluetooth reception, or combined with the ZEN DAC to upgrade the DAC’s headphone amp stage. As well as a headphone amp, it can double as a preamp to feed a power amp and speakers or a pair of active speakers.
In common with the other ZEN Series products, the ZEN CAN uses the same sturdy, aluminum enclosure. In the centre of the front panel is a smooth-acting rotary volume control, flanked on the left, by the power button, input switch, and gain control. Four settings in six dB steps – 0dB, 6dB, 12dB and 18db – enable the amp to precisely suit the connected headphones; unity gain (0dB) is useful to ensure low noise with sensitive in-ear monitors, while the higher gain settings help dealing with more demanding impedance loads, delivering better dynamic headroom.
To the right are a pair of headphone outputs – a 6.3mm (1/4") output for headphones that have a standard single-ended connector (compatible with all headphones) and a 4.4 Pentaconn balanced output for headphones offering balanced connection. An increasing number of high-quality headphones and in-ear monitors offer the option of detaching the cable and upgrading to a 4.4mm Pentaconn connector (recommended for high-impedance headphones).
Next to the headphone sockets is a button to engage the latest versions of iFi’s ‘XBass’ and ‘3D’ sonic tailoring options for headphones. XBass adjusts frequency response to enhance low frequency performance – particularly useful with open-back headphones that ‘leak’ deep bass. 3D compensates for the ‘in-head localization’ effect that widens the headphone soundstage to deliver a more speaker-like experience. Both XBass and 3D engage purely analog processing and may be bypassed entirely if preferred.
Around the back, the ZEN CAN offers stereo RCA and 3.5mm single-ended inputs, plus a balanced 4.4mm Pentaconn input. A 4.4mm balanced output is also provided, to connect to power amps and active speakers equipped with a balanced input – either a Pentaconn 4.4mm input, or XLR inputs via a 4.4mm-to-XLR cable. This balanced output can also be used for single-ended connection if no balanced input is available. All the ZEN CAN’s inputs and outputs are gold plated for optimal conductivity.
The ZEN CAN uses a balanced, symmetrical dual-mono design and follows the work of John Curl, now a technical consultant for iFi, in close cooperation with iFi’s in-house technical team, headed by Thorsten Loesch. A number of key elements have trickled down from the discrete Class A circuitry developed for iFi’s flagship headphone amplifier, the Pro iCAN, which is 12 times the price of the ZEN CAN.
For such a modestly priced headphone amp, the ZEN CAN delivers 1600mW (7.2V) into 32 ohms from the single-ended output, with 15V+ available to loads of 300 ohms or more through the balanced output, ensuring it supports even current-hungry planar headphones.
The ZEN CAN uses many discrete, high-grade surface-mounted components to maximize sonic purity, such as TDK C0G and Panasonic ECPU capacitors, and ultra-low-distortion thin-film resistors. iFi’s custom OV4627 quad-amp stage features four independent FET op-amps using a ‘folded cascode’ design, with low-impedance feedback circuitry to optimize performance.
A further custom op-amp is used for the input stage, which features automatic level matching and feeds a TOCOS precision potentiometer, while the fully discrete, balanced, complementary bipolar output stage utilizes the same Class A buffer found in the Pro iCAN. The power supply circuitry includes ‘stealth mode’ voltage conversion, again derived from the Pro iCAN, with linear regulation, noise filtering, physical isolation from sensitive audio circuits and 4,000uF capacitance to keep ample power in reserve to respond to musical transients.
Even the way the ZEN CAN switches between settings has been engineered to ensure sonic transparency. FET-based switching is handled by a microcontroller, which only ‘wakes up’ when the user changes a setting. With all this painstaking attention to detail, the fact that iFi has succeeded in implementing such high-quality circuits in a device retailing at US$149 (€165) is worth noting.