iCAN SE: Technical Notes (1). TubeState, the engine at the core
Following on from the Features outline, is a subject oft discussed around iFi gear. We hope you find it informative.
The iCAN SE has TubeState, 3D for Headphones, XBass and real high power. Each of these special features will be covered in more depth. So it goes above and beyond what other headphone amplifiers are capable of. Even the big headphones gulp when they see the iCAN
TubeState® is the real difference
At AMR/iFi we have always loved the sound of tubes and have produced Tube Equipment under the AMR brand name in the ultra-high end arena for going on ten years.
The venerable AMR CD-77: with 6 tubes no less!
For iFi, where possible, we always strive to recreate the (original) valve sound using solid-state circuitry (a quest we are hardly alone in) and we wanted to include our best effort on this account as part of the iFi Headphone Amplifier that became known as ‘iCAN micro.’ It sounds darn good and despite its modest size, it has garnered a nice following.
Some have asked if the Class A circuitry is behind its ‘sonic magic’ – we can answer yes and no. Yes in the sense that Class A sounds to our ears the most desirable and is the minor constituent but no in the sense that there are many other very nice sounding Class A amplifiers yet the micro iCAN is just has that
je ne sais quoi despite its modest size and market position.
TubeState® – the reason behind the iCAN's sonic ‘rightness’
Now most people would tell you that "real tube sound with solid state - that's just impossible". But it is possible and it really is worth the effort.
Those who can recall the tube sound or who listen to real tube amplifiers will be able to relate to this... Tubes sound warmer than transistor circuitry, but not overly-warm (when done well) - they render the bass much more naturally than solid-state. Tubes render the presence band differently, communicating the 'feel' and 'emotion' of the music. The treble sounds as clear as the peal of a small bell, but not edgy, so it is easy to discern between similar instruments.
Of course, there are some circuits that just have a tube in there for the sake of having it and it is almost an afterthought as it is not an integral sonic component. But with tubes implemented well, music morphs into something everyone enjoys. Tubes always ‘tell the story’ better!
Tubes run hot, take up a fair bit of space and cost a fair bit of money; solid-state can be made to be small, run cool, and be very affordable. Wouldn't it be great if we could get ‘tube sound’ from solid-state gear? Okay, not an exact replica of real tubes but as blinking close as possible. This is what we have done with the TubeState
® amplification stage. This is what the original iCAN and the iCAN SE have that others don't have which gives them the sonic edge.
TubeState® - Captain, it cannae work or it just adds gobs of distortion!
There are various arguments as to why solid-state cannot do the valve majik and also a number of cases where there are claims of ‘tube sound from solid-state.’
Usually ‘tube sound from solid-state’ focuses on adding the characteristic distortion of Tube circuits, but we have long maintained the key to tube sound is not directly found in just added harmonic distortion. Adding distortion only is mere ‘mimicry’ of one singular aspect of how tubes behave and often not the one that is sonically important.
How much the result approaches the result of real tube circuitry varies widely, but in many cases the words ‘hilarious dummy sound’ come to mind. We would be one of the first to admit this. The key is not add distortion, but to avoid certain types of distortion.
TubeState® - a blend of theory and experience
The TubeState
® technology is the result of nearly four decades our Chief Designer Thorsten Loesch spent with tube and transistor gear, building kits or published designs at a young age and also repairing and refurbishing classic tube gear, not just HiFi but also Guitar and Bass Amplifiers as well as Pro-Audio Devices added to which were many years of research, exhaustive development and testing culminating in publishing or putting into production well-regarded designs in both Tube and Solid-State circuitry, analogue as well as digital.
Once it is understood which specific distortions are endemic to solid-state circuitry and are pernicious with respect to subjective sound quality, we can eliminate these from solid-state circuitry; without adding on tube like distortion and noise. This is how TubeState® does 'Tube Sound from Solid-State' ie: THE specific circuit used in the CORE amplification.
As an aside, it is worth noting that Class A is a totally separate point, relating to the output stage primarily/only. Small signal stages (voltage amplification stages) almost invariably operate in Class A, even using the cheapest Op-Amp. Only if loading of the gain stage becomes notable (low input impedance pro audio gear or headphones) do these circuits leave Class A.
In summary, what defines the iCAN SE's special sonic signature is having TubeState® as the core engine and the Class A power stage being the afterburner.
They dovetail perfectly to make sure the sonics deliver and the music flows. All with 4,000mW on demand.
And the metric we use is not whether the bass or treble is better but whether you spend more time listening? Because this means your brain is telling you something - this just sound 'right so more of the same please.'
Further reading:
“Why tube? iFi references a study by Jürgen Ackermann for the Frankfurt University of Music and Performing Arts where 50 participants took part in a blind listening study listening to a tube and a solid state system.
The results showed the participants felt the tube system improved their overall level of enjoyment by 187% where the solid state system made 30% of participants feel worse after listening. This study was referenced in the excellent piece by Markus Sauer for Stereophile titled, "God is in the Nuances*", highly recommended reading. So why tube? It can make you enjoy listening to your music more, the proof of which lies in the listening."
*http://www.stereophile.com/features/203/index.html
Next time, part 2:
So what's the TubeState® secret? 
