iFi Audio Pro iCan Fully Balanced Headphone / Line Stage Amplifier
iFi is proud to present its flagship Professional ‘Pro’ series. The first product in the range is the Pro iCAN – a studio-grade headphone amplifier AND audiophile line-stage. Inside beats ‘two hearts’ as there is are two individual Solid-State and Tube amplification sections – selectable on the go.
There is nothing quite like the Pro iCAN; literally.
Flagship, studio-grade headphone amplifier...
The Pro iCAN will for many, be used as a top-of-the-line, headphone amplifier that drives anything and everything – from CIEMs through to the most difficult to drive headphone ever made, the AKG K-1000.
Headphone Connections
The Pro iCAN has the following headphone connections:
XLR 4-pin Balanced
XLR 3-pin x 2 Balanced
6.3mm x 2 Single-Ended – able to drive two headphones simultaneously
Balanced – uses the iFi ‘SEC’ Balanced System*
3.5mm TRRS Balanced – with built-in fixed iEMatch (as first seen on the micro iDSD for CIEMs/IEMs)
3.5mm TRS Single-Ended – with built-in fixed iEMatch (as first seen on the micro iDSD for CIEMs/IEMs)
‘SEC’ Balanced System* = Single-Ended Compatible Balanced
– directly compatible with standard non-balanced 6.3mm headphones
– Balanced operation using custom headphone cable with 2 X 6.3mm Plug
Further, Gain is adjustable from 0dB/9dB/18dB. The Pro iCAN can output >10V in Single-Ended mode and 20V in Balanced-mode. The 20V mode is equivalent 100W into a 4 Ohm speaker. So the Pro iCAN can drive almost any headphone into very hard-clipping (protection circuitry typically kicks in under such circumstances).
…and audiophile line-stage.
The Pro iCAN has at the core, a Japan Alps motorised rotary volume potentiometer. This is the ‘6-Track’ version with 4 tracks used for a true balanced volume control. This is the litmus test for any amplifier to see if it is truly balanced, or operates internally in single-ended mode. Those using ‘2-Track’ volume controls may offer balanced in and out, but are not true balanced designs. The Pro iCAN however is fully-balanced from beginning to end.
In terms of flexibility, 3 single-ended and 1 balanced inputs and 1 balanced and 1 single-ended output, the Pro iCAN is a full-function audiophile line-stage that is at home in many expensive hi-fi systems. Its user-selectable Solid-State/Tube amplifiers remain and so are 3D Holographic˚ for Speakers and XBass˚ for ultra-fidelity home audio systems.
In the Pro iCAN, when the Tube circuit is selected the solid state part is completely off and it is NOT in the audio signal path. Equally, if the Solid state circuit is selected the solid state part is completely off and it is NOT in the audio signal path.
Most important of all, the Pro iCAN is balanced all the way through – from beginning to end. This is what we call ‘True Balanced’ and is the extremely rare in High End and a first in Professional Audio with the Pro iCAN.
General Electric 5670 x 2pcs
Compared to high-end headphone amplifiers, the tube stage of the Pro iCAN is different in two-ways. First, we don’t use good-quality 6922s or similar. Instead we use the very best; General Electric 5670 which is the premium variant with a different pinout.
Second and just as important is the circuit design. Unlike other headphone amplifiers that have the same circuit and just switch in/out the tube section, the Pro iCAN is the very first of its kind that has two individual input circuits – one tube and one Solid-State. This results in the best sonics of both worlds because the signal path is the shortest and there is no compromise to ‘shoe horn’ the tubes into an already existing solid-state circuit.
For the first time, one can enjoy both the sound of Solid-State and Tubes in a single package (rather than as an ‘Effect Type’ add-on within an otherwise conventional solid-state design) and be able to switch in real-time. For some recordings and headphones/loudspeakers, Solid-State may sound ‘more lively.’. For others, Tube and Tube+ (especially Tube+) will sound more ‘luxurious.’ Select the one that sounds best for that particular moment, be it the recording, the mood or even the weather. After all, enjoying music is an experience to be savoured and not a scientific research exercise.
We haven’t stopped there. We are tube lovers and we appreciate sometimes there is a need for even more tube-like sound, there are two tube settings – Tube and Tube+. The Tube+ position reduces overall loop-gain and thus negative feedback to the minimum. This gives a different trade-off between the tube’s natural harmonics and the transient performance.
Class A Solid-State, J-FETs and Fully-Discrete
The Solid-State amplification section of the Pro iCAN is just as seriously executed as the Tube amplification section.
The amplifer audio circuit is a development of iFi’s revolutionary ‘TubeState’ design. It is fully discrete, fully-balanced with either tube or J-FET input switchable, bipolar second stage and MOSFET-buffered bipolar class A Power stage (with Class AB for low impedance headphones at very high levels). The resulting circuit may be best described as ‘tri-brid’ where each device is used to greatest sonic advantage while minimising any drawbacks. Furthermore, the circuit is pure DC coupled to avoid using any sonically-degrading coupling capacitors.
3D Holographic® not one but two circuits
There are two 3D Holographic SoundSystems:
For Headphones: (Headphone Outputs)
The Holographic for Headphones is not based on a standard cross-feed system, as found in some High-End headphone amplifiers. Many so called ‘3D systems’ are usually DSP based that artificially effect the sound and add unwanted reverb in order to simulate a ‘spacious‘ type of sound.
It’s true that traditional cross-feed tends to produce an ‘out of head’ sound, but with much diminished spatial components and a narrower soundstage, sometimes almost approaching mono. Most DSP based 3D designs produce an unnatural, echo-like sound, which may initially be impressive, but soon becomes tiring.
By contrast, Holographic for Headphones, provides not only ‘out of head’ placement of the sound sources, but renders the whole sound field in a manner that strongly parallels listening to loudspeakers in a normal room, all achieved without the added reverb. This is the first system in commercial production to achieve this.
OFF
30° Loudspeaker Angle
60° Loudspeaker Angle
90° Loudspeaker Angle
3D Holographic Sound for Headphones
As stereophonic recording and reproduction became widespread in the 1950’s, a glaring problem was noticed when replaying such recordings through headphones.
First formally described by Benjamin B. Bauer of CBS and previously Shure Brothers, in his 1960 patent filing for the US Patent # 3088997A as a “gross distortion in space perspective” and later gained the name “in-head localisation”. BB Bauer proposed a correction circuit, quite similar in nature in fact to the EMI Stereosonic Circuit originated by Blumlein, but with a near opposite transfer function.
Like the Blumlein/EMI Stereosonic corrector, the Bauer/CBS corrector was eventually forgotten and never gained much traction. With the increase in headphone listening in the 1980’s due to portable stereo radio’s and the visionary Sony “Walkmen” Cassette player, the Bauer/CBS corrector was revived and became known generically as Crossfeed.
However, while traditional Bauer crossfeed and its various derivatives do substantially remedy the “in-head localisation” problem, the result is a sound stage that may be best described as “wide mono”, much of the natural spaciousness of recordings are lost.
So Bauer/CBS derived crossfeed is still a rare feature. More often than not gimmicky and sound degrading DSP algorithms are promoted as enhancement to headphone listening that only distort the original recording more, rather correct the fundamental problem.
At iFi we have been building on research that extends as far back as the late 1980’s at the RFZ in Berlin, which suggested that a very different Matrix to the Bauer/CBS one is required and that additional martix coefficients are required to present a natural and spacious soundfield, like that from a speaker based stereophonic playback system.
Starting with this foundation we have applied further research and large scale listening tests to derive a purely analogue matrix, that translates a spacious stereophonic recording with good imaging when replayed on speakers into its equivalent when listening to headphones. That is 3D Holographic Sound for headphones, not crossfeed, not crossfeed plus something, but a fundamentally new way to correcting recordings made for speakers to replay correctly on headphones.Like the Blumlein/EMI Stereosonic corrector, the Bauer/CBS corrector was eventually forgotten and never gained much traction. With the increase in headphone listening in the 1980’s due to portable stereo radio’s and the visionary Sony “Walkmen” Cassette player, the Bauer/CBS corrector was revived and became known generically as Crossfeed.
However, while traditional Bauer crossfeed and its various derivatives do substantially remedy the “in-head localisation” problem, the result is a sound stage that may be best described as “wide mono”, much of the natural spaciousness of recordings are lost.
So Bauer/CBS derived crossfeed is still a rare feature. More often than not gimmicky and sound degrading DSP algorithms are promoted as enhancement to headphone listening that only distort the original recording more, rather correct the fundamental problem.
At iFi we have been building on research that extends as far back as the late 1980’s at the RFZ in Berlin, which suggested that a very different Matrix to the Bauer/CBS one is required and that additional martix coefficients are required to present a natural and spacious soundfield, like that from a speaker based stereophonic playback system.
Starting with this foundation we have applied further research and large scale listening tests to derive a purely analogue matrix, that translates a spacious stereophonic recording with good imaging when replayed on speakers into its equivalent when listening to headphones. That is 3D Holographic Sound for headphones, not crossfeed, not crossfeed plus something, but a fundamentally new way to correcting recordings made for speakers to replay correctly on headphones.
For Loudspeakers: (Line Outputs)
The Holographic for loudspeakers® is an analogue matrix circuit that has two distinct functions:
1. Corrects the fundamental spatial distortion in stereo recordings;
2. Increase the width of the apparent soundstage beyond the width dictated by the loudspeaker placement. The Holographic for loudspeakers® is an analogue matrix circuit that has two distinct functions:
OFF
+ (Original recording width)
30°+ (Original Recording Plus 30 degrees)
60°+ (Original Recording Plus 30 degrees)
Reference class parts quality
The Pro iCAN employed TDK Japan-made C0G type capacitors and Vishay MELF type thin film resistors. These are complimented by Panasonic Japan-made ECPU Film Capacitors explicitly designed for audio use with extremely low distortion (<0.00001% @ 1V/10kHz).
We employed ELNA Japan-made Silmic II capacitors for the power supplies. These use special silk fibre paper for the isolating barrier resulting in decreased odd-order distortion and reduced microphonics/mechanical resonances.
As one can see, the Pro iCAN despits its ‘desktop’ footprint is absolutely chocked full of premium components yet with a 4-layer pcb, has the ultimate topology in signal path layout/grounding.
There is just no more ‘real estate’ left to develop. It truly is deserving of the iFi flagship mantle.
