I appreciate this review. Here’s my own take on the successor to this unit.
I recently purchased the Pro iCAN Signature, which seems to significantly overcome the output limitations of its predecessor—it comes with a balanced 4.4 mm headphone output, a single-ended 3.5mm, both balanced and single-ended 6.3mm jacks, a stereo XLR balanced jack, and dual-mono left and right XLR balanced jacks on the front panel, along with unbalanced RCA and balanced XLR line outputs on the rear panel. It also adds a wireless remote with a mechanized volume pot, and comes with a very robust “iPower Elite” ANC power supply—whether this offers any benefits is unclear in the absence of measurements.
They also claim to have revised the internal circuitry with “higher grade” components, and the amp now advertises a balanced output power of 14 watts (!) at 16 ohms (4.8 watts single-ended). There are three gain settings (0, +9db and +18db), along with four input stages—three unbalanced RCA inputs and one balanced XLR input, all on the rear panel. There is a dial on the front to select between inputs.
It comes with a tube upgrade as well, with matched NOS GE 5670s, apparently from a proprietary supply they managed to obtain somehow. This is the equivalent of WE 2c51s and 396A’s, along with the matched NOS Bendix 5670s I rolled into mine (note that this voids the warranty, as the chassis has to be disassembled to access the tube sockets).
The tubes do glow on their own, but I noticed that iFi added an LED lamp beneath the tube section to artificially enhance the effect (personal opinion on whether this is nifty or cheesy). In my experience, I have noticed none of the audio interruptions Amir described when switching between solid state and tube modes in the original. It does still have the Tube+ option, but I dislike the sound and don’t use it.
I paired this unit with the Topping D90se I purchased on the advice of Amir’s testing and review, and I’ve been quite happy with the results. It certainly has plenty of juice to drive any headphone, including my Utopias and Susvaras. I sought it out mainly for its analog bass enhancement, which has now been expanded to provide boosts at four discrete low end frequencies, all with some Q overlap—and with it engaged I can overcome the roll off on the Utopias without the use of external DSPs. The added bass is subtle and does not seem to cause any boominess or loss of detail to my ears.
The unit still includes the “3D holograph” crossfeed equivalent intended to mimic more speaker-like conditions, and although I cannot say whether they improved this function in the Signature, I experience the same tone alterations and gutting of the bass that Amir described in his review of the original, and I never use this feature. Some have claimed that it is more effective in floor or bookshelf speaker setups than with headphone use, but I haven’t tried this to confirm—and the claim seems counterintuitive.
One controversial feature that has been useful to me is iFi’s ieMatch tech that they integrated into both the 4.4mm and 3.5mm headphone jacks. The execution of it here seems entirely different from the passive nature of the external devices they sell, which are meant to be placed in line with the headphone cable and have to be manually set by the user (with the guidance of ifi’s “Headphone Calculator”). As it’s employed in the Pro iCAN Sig, the ieMatch circuitry allegedly “detects” the sensitivity of the headphones attached, and makes adjustments to the output impedance accordingly—ostensibly to improve the S/N, per iFi. I cannot speak to the logic or validity of this claim without the assistance of those with a higher level of EE knowledge than I.
But on practical terms, when I previously used the balanced XLR headphone jack with my Utopias, I was forced to choose the lowest gain setting to obtain optimal volume ranges. At this zero gain setting, particularly when I had the xBass engaged, I experienced significant clipping at higher volumes, with the usual alarming pop coming from my drivers. However when I eventually switched to a 4.4mm headphone cable and ieMatch was engaged, I was now able to kick up the gain to 18db, and could not get the amp to clip no matter how much bass I threw at it, well above comfortable listening ranges. I experienced similar results with my Susvaras and Z1Rs. To my anecdotal ears the results are fantastic.
To my knowledge, other than perhaps the DAC/amp/DSP RME ADI-2, I know of no amp-only offering that includes ASP bass enhancements like the Pro iCAN Signature does, although I welcome feedback with alternatives. If this weren’t my only amplifier, I would gladly submit it to Amir for his assessment, but hopefully another user or iFi themselves will consider doing so, to verify if the Signature does indeed resolve the issues Amir encountered with the original.
