We've recently received one of iFi's brand new Pro iCan Headphone Amplifiers / Pre-Amp's so thought we'd run it through it's paces to see how it sounds and works. Feel free to pop by our Wellington Store if you would like to have a listen.
The iCan is marketed as a reference level product, so it has been reviewed as such. We compared it using our most resolving headphones and sources, and compared directly against the widely lauded Moon 430HA fully balanced headphone amplifier.
Basic Info / Features:
The Pro is apparently an all analogue, fully balanced design, with several different modes of operation. It features a pure class A (Or as iFi terms "tube-state") section, a relatively serious tube section based around the famous GE 5670 tubes, as well as a more "luxurious" tube+ mode. According to iFi this Tube+ mode has a lower loop gain, which minimises negative feedback, creating an even more "tube-like" sound.
One particularly nice feature of the Pro iCan is that you can switch between these modes from the front panel, while the unit is operating. Meaning if you change songs, you can also change the amplifier mode to the amplifier mode which sounds best for the particular piece of music.
The Pro iCan also has huge variety of different front panel connection options, including four pin balanced, 3 pin balanced, two 6.3mm Outputs and two 3.5mm outputs, as well as a 3.5mm connection capable of powering a 4 pin TRRS balanced 3.5mm cable if necessary. Basically, this means whatever headphone connection you can dream up, the iCan will power it.
The iCan also features selectable xBass (A form of bass boost circuit) and what iFi terms 3D Holographic, which is a circuit designed to replicate the imaging found in stereo speakers, in headphones. A little more on these adjustments in the sound section of the review.
As many readers know, it's easy and cheap to whack on some balanced inputs and outputs onto a device, but a whole other kettle of fish to implement a fully balanced internal design. With demanding headphone listening in particular, the balanced operation can actually significantly improve the measured sound quality of headphones.
From Tyll Hertson (Inner Fidelity.com):
"Basically you are driving both sides of the coil in each earpiece. This means that the load looks half the impedance to a single sided drive scheme. Since both signals are driving you effectively double the slew rate (which is the transient speed of the drive signal). But maybe most importantly, you get rid of the common connection in the ground the two drivers share. The impedance between the common connection on the ground side of each driver to the actual ground of the power supply allows a common signal to develop on the ground side of each drive effectively providing crosstalk between left and right channels."
Many of these features also apply to the pre-amp section as well. Including the fully balanced design and volume control, as well as separate xBass and 3D Holographic circuits for the pre-amp outputs. It also has a basic remote control.
Build Quality Impressions
The Pro iCan seems overall to be built to a very high standard. The volume control and front panel connections all seem solid and sturdy. The aluminium casing is slightly lightweight but is quite a nice finish with interestingly shaped cut-outs. The input selection and other switches and dials all seem sturdy to touch.
I found this video showing a full tear-down of the headphone amplifier, which appears to show iFi have really gone all out with the design and construction of this unit.
The iCan is supplied with a separate switch mode power supply. Usually this isn't the best sign as they are typically of average quality, however iFi are well known for producing much higher quality switch mode power supplies than their competitors. It's not too large so doesn't get in the way of other wall warts.
The base of the unit is an interesting nylon design, presumably to help the amp grip to a surface. However, due to the relatively compact size of the unit it seems to move around a fair amount when attaching balanced connections. You will typically need to hold the amp with one hand while connecting or disconnecting anything.
In use, the iCan seems to get quite hot. A fully class A headphone amplifier will typically do this, it's probably not something to seriously worry about, but generally speaking it will be worth keeping an eye on. I wouldn't leave your headphones (or anything else) on top of the unit.
Starting with the Solid State Mode, the first headphones we tried were Sennheiser HD800s. Immediately, a very large, wide sound-stage is evident, with instruments placed quite accurately. Bottom end control was excellent although there wasn't quite the impact and slam achieved with Moon's 430HAD. Mid-range and vocals seemed quite present, and spooky accurate. This amp is quite capable of spine-shivering moments.
My only gripe with this combination was that the top end seemed a little grating. It seemed very clean and extended, but just a little too much emphasis. Sometimes cymbals felt like they completely cut through the rest of a recording. It's worth noting that when listening to the same tracks in the standard tube mode, this emphasis seemed to disappear completely, leaving a very smooth response (to my ears)
The tube+ mode to my ears, is a little heavy handed. However, I can see how it would be fun with certain bright recordings or aggressive sounding headphones, such as the Grado RS-2.
Changing now to Oppo PM1's, we used both the stock OCC cable and Wireworld's custom eclipse balanced cable. In the solid state mode, with the balanced cable is basically some of the best sound I have heard from these headphones. Some of my personal downsides with the PM1's are basically their lack of very extended bottom end and an overly smooth top end. The power, control and finesse through the frequency range really show off these headphones.
Experimenting with the selectable bass boost, I found the 10Hz setting actually quite pleasant and subtle with these headphones on a variety of recordings. Both the 20Hz and 40Hz settings were far too heavy handed for my preference. With some particularly meager headphones, or for bass lovers, this might still be useful I suppose.
Experimenting further with the 3D holographic setting, I found it to be surprisingly subtle and effective. Normally, I am militantly against cross-feed circuits, which typically muddy the low end and confuse top end detail. This is the first I have found that is genuinely effective at creating a slightly more focused image, without taking away other aspects of a recording. I highly recommend you try this feature as with many recordings it will make them seem a lot more natural. My preferred setting with both the HD800's and PM1's was the 30 Degree setting.
This is certainly a reference class headphone amplifier. No headphone or recording is perfect, so a tool that can make imperfect headphones and recordings sound bearable, while still showing off the best parts of top end headphones.
A good quality source and balanced cables for any headphones that are capable, are highly recommended to get the most out of this unit. Set up correctly, this headphone amplifier is capable of taking already great headphones to dizzying heights.