I first became aware of the Cayin brand some years ago as a neophyte to the Head-Fi hobby when a friend bought a C5 portable headphone amplifier.
Driving a pair of Beyerdynamic DT880 250 Ohm headphones, this svelte and well built powerhouse performed brilliantly, to my surprise it must be said.
It was the best of it's kind then, making comparable Fiio offerings seem anemic by comparison, and it remains a contender now.
Fast forward to present day, and Zhuhai Spark Electronic Equipment Company, better known as Cayin for the past 20 years, has rightly earned a serious rep in the community for their impressive tube amplifiers and DAPs. They do however also make a solid state, fully balanced headphone amplifier, the iHA-6, the subject of this brief review.
I felt compelled to air my impressions, not because
Lumous Audio, in their wisdom, decided to loan me a unit for a while to "get my opinion" but because it is the finest sounding headphone amplifier I've heard south of twenty grand South African (about USD$1300).
More amazing is that it retails for a ZAR shy of
half that (at the time of writing).
So I've gotten to the punchline upfront: it's a stellar performer, and it did not take long for me to come to this conclusion.
Out of the box one is struck by the solid mass of the thing, only 7 by 24 by 25 centimeters but weighing in at a dense 4 kilograms.
4mm thick aluminum panels are nicely finished in silver with nary a screw in sight.
Upfront one finds no less than 4 different headphone outputs covering low and high impedance 6.35mm and both 3 and 4 pin balanced XLR connectors by Neutrik.
The "low" has an output impedance of 10 Ohm whilst the "high" is 120 Ohm. More on this anon. The balanced outs both present a load of near as dammit Zero Ohm.
An illuminated power button resides next to three push-buttons for selecting RCA or XLR analogue inputs, high or low current delivery and low and high gain respectively.
The ability to increase the amp's quiescent current is a very neat trick too. Power output is decreased slightly while current delivery is increased.
This works very well indeed on low impedance headphones, and can be very noticeable or not so much, headphone dependent.
This should be the default mode for most Planars.
A large, onyx fronted silver knob controls the very smooth ALPS RK27 Blue fully balanced 4 way pot.
Since there are no pre-amp functions the rear panel is spartan, housing one pair each of RCA and 3 pin XLR connectors along with the usual IEC power socket.
I might mention that build quality and component choice are both excellent, and not just "at the price" - at any price.
Switching on one notices that the illuminated power button blinks three times and then settles into a constant white glow.
Protection against DC offset on power up. Nice. My headphones thank you. They don't need to be unplugged, ever.
Having given it 5 minutes to warm up I connect the trusty Sennheiser HD6XX to the 4 pin output on low gain and low current settings.
Source is a Windows 11 PC connected via AQ Pearl USB to Resonessence Concero DAC and thence single ended to the iHA-6 which coverts the signal to fully balanced internally using a bridge-tied load (BTL) circuit that converts single end input to balanced before feeding into the amplification circuit. Any signal loss via this process is said to be inaudible.
I almost always start listening with the HD6xx (and previously HD650) - since I know its sound so intimately, I can almost immediately hear where an amp is at based on this synergy. And synergy there certainly was! Santana's
IV album in 24/48 FLAC sounded full, detailed and engaging at moderate volume - around 10 on the pot.
Absolutely no need to use high gain, the Cayin outputting a handy 1.2W into 300 Ohms...did I mention this thing is POWERFUL??
Andy Kong uses both the HiFiMan HE6 and Abyss 1266 to demo the iHA-6 at shows. Two of the most difficult to drive (properly) headphones on the planet, and this in front of a rabid and knowledgeable crowd...either a very brave man or very certain that his amp can do justice to these two behemoths.
Power is the last thing an owner needs to worry about, so let's put that to bed: 7W @ 32 Ohm balanced, 3W @ 120 Ohm and 600mW into 600 Ohm.
According to the Rolls Royce Scale, sufficient. Oh boy, is it ever sufficient..!
I have not needed to use the high gain setting (+12dB) at all, and that should speak volumes.
All that power is delivered with a velvet glove-like delicacy though, refined and smooth when required but capable of huge bursts of dynamic range and slam without any hint of compression or clipping. I simply loved the way it allowed the HD6xx to sound better than I've ever heard it, and I've heard it from MANY sources.
It is well-known that the venerable Sennheiser scales with better equipment and this absolutely holds true here.
There is no "veil', perceived or otherwise.
Midrange is rich and full-bodied as it should be and in fact all frequencies are evenly presented.
Similarly it gets the best out of all my headphones, from HE400SE to AKG K701 to Fostex TH-X00.
Three very different headphones, all of them fully and authoritatively driven.
I heard detail from the HiFiMan I didn't know it could resolve.
Bass on the power-hungry AKG filled out and became...more...and better defined, with seemingly much less roll-off.
The 25 Ohm Fostex is sensitive and easy to drive and the iHA-6 allowed me to experience what it could
really do when subjected to massive power, current and control.
This headphone just thrives on current and with the amp in high current mode it's the best I have heard them.
They deliver legendary bass but now it's even better defined and there seems no end to its extension.
Highs in particular have even better extension with nary a hint of sibilance.
Considering that the Mahoganies have a tendency to sound a bit "zingy" with the wrong amplification, this is impressive control.
Whilst I would not call the iHA-6 a reference amp (it is ever so slightly warm of neutral), compared to the Topping A90 I found it to be more "musical". Not easy to quantify but noticeable once one has had a decent listen - for "musical" one might substitute "organic" or 'natural". Listen to Amber Rubarth's "Sessions from the 17th Ward" on DSD and you'll quickly understand the difference.
Perhaps the only negative about this amp might be the high output impedance of the SE headphone jacks, but truthfully its a non-issue for me. It is designed to deliver as a fully differential device and should be used that way.
In short, it sounds great running SE, but it is exceptional when used balanced.
'Nuff said!
I could ramble on, but I've got too much music to listen to...the honeymoon is not yet over.
It is all the headphone amp most (normal) people should ever need and redifines the cost to performance ratio in my book.
I love switching it on every day and can
highly recommend it.
UPDATE 08/04:
Having now had the opportunity to hear my HD6xx using the 120Ohm SE output I will need to change my initial opinion.
This is in no way a con now that I understand why it's there in the first place, rather a stroke of genius from the designer(s).
As per my thread post:
There's definitely a heftier, rounder bottom end but no bleed into mids and no loss of detail (not that the HD6xx is the most resolving headphone to begin with).
Yes, it's a tad warmer but I like it!
Yes, I would say slightly more euphonic (ok, tube-like) which was precisely the result I was hoping for.
HF seem to be largely untouched, but that's perhaps due to me not hearing much above 13kHz...
I will need a bit more time to hear if I can pick up on any LF nasties, but so far, so good.
Using the 120Ohm SE output with HD6xx initial impressions are...very positive!
I will need a bit more listening time but will report back shortly.