Acknowledgment   

Thanks Airist Audio for organizing this tour and producing this brilliant amp. I was the last stop on the tour and bought this amp directly from Airist Audio (without sending it back) with a small discount.

Introduction

First, I’ll tell you a bit about me, below the fold. Every reviewer is biased, but we all have different flavours of bias. I think my flavour is maple walnut, cause I’m the sweet mildly complex stuff with a bit of crunch and overall neutral visual tone that is an ironic reward for a trip to the dentist in the winter cold of Fairbanks, Alaska (my home town). Like dentists, audio gear is pricey, and the good ones don’t charge that much different than the bad ones. It doesn’t matter if it’s cold outside give me that creamy smooth frozen yummm—Hot Licks, RIP. Frozen eyelashes and blue lips build character.
 

 

 

Airist Audio: aiming for the stars and quicker student loan debt relief?

Airist Audio is a New York startup founded by a small group of audiophile tech nerds with a passion for audio. These 5 baby-faced entrepreneurs have some serious school credibility, these kids are either done with or doing degrees at Columbia, Harvard, MIT, etc…. If these kids are anything like me, their student loan debt would make most of the bourgeoisie blush. That’s the American education system for you—I saved money by getting a degree in England. I hope this audacious endeavour pays off some of those debts. Go get ‘em kids. Look at those faces. So much courage!
 
 
 
 
 
If you’d like to know more about this start-up from New York, check out Airist Audio’s website for some hot pics and information. They don’t skimp on catwalk worthy New York style (I'm so sorry, I had to do it).
 
 

 

Vital Statistics (what the manufacturer says about their gear)

Audio gear comes with fancy charts and marketing descriptions. Here are some from Airist Audio. The main selling points that Airist Audio puts forth are a completely flat frequency response accomplished with a completely accurate phase response. They also boast of ridiculous resolution, silence, and lack of distortion. The proof is in the pudding. This amp is neutral, silent (with right impedance headphones), and instrument placement is special. To the charts and graphs!
 
 
 
 
 
 
 
 
Yep, that tape measure isn’t drooping at all. Ruler flat on frequency response. Looking below, we see something I’ve never seen and can’t really judge without having sufficient math or engineering expertise, a flat phase response across all frequencies. From the explanation on the website, this means that instruments are in the exact place they should be without bleeding into other instruments. I can confirm this, and its gorgeous.
 
 
 
 
 
Courteously, Airist Audio provided lots of numbers. Here are the rest of the numbers Airist Audio has provided:
 
 
The noise floor and SNR really stand out when listening.
Other features listed in the owner’s manual include the following:

1. 100% discrete power supply and amplification circuits
2. Minimum phase amplification with bandwidth from DC to 30Mhz
3. Active power regulation synchronized with the amplification circuit
4. No coupling capacitors or DC servo in the signal path
5. OCC pure silver wiring in the signal path
6. Highest grade toroidal transformer with a laser inscribed carbon steel core and American-made winding wires
7. Power transformer with overhead capacity rated at 5x power consumption
8. Class A output power with an internal chassis design that keeps the Heron 5 warm, not hot to the touch (without ventilation holes  on the top—winning!)
9. Soft start circuit protects your headphones from equipment destroying start-up peaks
10. Elite grade Mundorf capacitors in the main power supply

 

Form & Function

The Heron 5 is a big hunk of aluminum that has reassuring heft whilst maintaining lean lines and a serious stately stature. The amp has no visible screws and keeps the facia simple. It features a delicate curvature to the top and bottom of the facia, the Airist Audio insignia (like two birds flying in concert), a simple small power button, two headphone jacks marked high and low (more on that later), and a big stepped attenuator volume knob with a red LED line drawn in a black circle signalling the benthic depths of the joy pumping into your cranium. The Kraken, Leviathan, and Dandân battle in the depths here.
 
The back of the unit has has the IEC port, a pair of balanced inputs and a pair of RCA inputs. You can flick a switch to choose which you’ll be listening through. My balanced source died before I could get a chance to listen in balanced mode, so all my listening in this review was done in single-ended mode, which is fine, as the internals are single ended.
 
The front headphone jacks are somewhat confusingly labelled. The ‘High’ jack is intended for lower impedance headphones (Airist Audio says for better impedance matching), whilst the ‘Low’ jack is for high impedance headphones. I found that basically everything sounded clearer on the low jack (high damping factor) but it was also more prone to buzz, the high jack adds a bit of body to headphones and is slightly less prone to buzz. I don’t think either of these jacks are truly low impedance and Airist Audio doesn’t tell us any output impedance statistics. If I had to wager, I’d guess the low jack has an impedance of around 5. The reason for this being that my venerable RE0 iems (64 ohm impedance) had no buzz at all out of the Heron 5. Actually they sounded pretty darn great.
 
Inside the box are the unit, a manual, and a USA plug IEC cable. The manual is informative, with good diagrams, details about features, startup instructions, dos and don’ts for using the Heron 5 and a short FAQ. I would have liked if I could lay the manual flat—I had to type most of the above bullet points one-handed because the binding is too tight. The included power cable appears to be well made, but I didn’t use it during the review as I have a shielded IEC cable that has a UK plug. Airist should be making plugs for the region the amp is being sent to, not telling people to use an adaptor. This is something to fix in the future. I don’t have much confidence that my available adaptors will provide enough quality to the power lead.
 

 

Audio quality

In one word: spectacular. I used this with a number of pieces of excellent gear in the test-bed. Here are the constant parts:
 
Acer Revo RL70 mediaPC to LH Labs Lightspeed 2G USB Cable to iFi iUSB3.0
 
The LH Labs Lightspeed 2G cable adds definition to the upper end, blackens the background a bit and opens up the soundstage a bit. The iFi iUSB3.0 makes the background even blacker and increases soundstage in all dimensions whilst giving notes a rounder more natural attack and decay (review of iUSB3.0 here).
 
Other elements that were used include Atlas Element Integra interconnects, a LH Labs Lightspeed Micro USB, a custom made Van Damme 3.5mm to RCA cable, the Chord Mojo, the LH Labs Pulse X-Infinity, LH Labs Geek Out V2, and a pantheon of headphones. The mountaintop vista included such headphones as the Sennheiser HD600, Sennheiser HD800, HiFiMan HE6, AKG K1000, oBravo ERIB-2a, HiFiMan RE0, and Echobox Finder X1. I won’t list impressions with all of those headphones, but will attest that there was some buzz with the Echobox Finder X1 and the ERIB-2a (dependent on track and volume), but no buzz with the RE0.
 
The first setup I listened to was the X-Infinity feeding the Heron 5 with the Atlas Element Integra interconnects, a 2^nd Lightspeed 2G USB cable from the iUSB3.0 to the DAC, and the HD600 as the headphone. I nearly cried. I’ve never heard the HD600 sing like it does with the Heron 5. I listened to City of the Sun – to the sun and all the cities in between, and to Keith Greeninger & Alex deGrassi’s  Live at the Fenix (from Blue Coast music). City of the Sun is binaural and very immersive especially with the Heron 5. I was getting sound like a speaker presentation. Live at the Fenix has the best recording of a live acoustic environment that I’ve ever heard. The purchase of the set in advance for Live at the Fenix was the best audio decision I’ve made so far this year (all formats including DSD256 for $25). Listening to the album with the HD600 fed by the Heron 5 was like sitting in the front row of the concert venue next to the very California lady telling Keith Greeninger when he’s done a ‘nice job’ just to your left.
 

 
My X-Infinity packed it in the next day (RMA in process—I’m sad), so I listened with the GO V2 with all other elements the same (adaptor to use the interconnects was a cheapie ebay number, but works). The GO V2 doesn’t have as much stage or as much precision as the X-Infinity, but it still pairs wonderfully with the Heron 5. The HD600 continued to sing, but not like any long-necked marsh bird you ever heard. The Heron should be the Blackbird 5. There are few things as pretty as a blackbird’s song sweetly sung while the sun is just awakening dusky eyed from its nightly slumber. With 9bach – Llwynog in 24-96 the background is completely black, silent. The soundstage has exceptional depth and height. Instruments are coherently arranged with articulate interplay in a well-defined sonic space—percussion instruments hang in the air and echo in the soul. The bass grooving throughout the track has excellent weight and tonality. Notes are well-rounded, but with excellent precision. I can find no flaw in the transient representation. The sound is clean, yet musical. There is no white coat sterility here. The sound is like a buxom renaissance nude with a coy smile that grows ever more suggestive and more vivid in your mind with more time spent with her. The canvas of the tune is alive with sonic brush-strokes.
 
Turning to Fleetwood Mac – Never Going Back Again (a track I like for the acoustic presentation) reveals no new insights, but provides a pleasurable listen to the articulate guitar with organic attack and decay.
 
There are moments when the Heron 5 tells you the truth about your music, and you might not be ready for it. When listening to Father John Misty – Nancy from Now On, the Heron 5 reveals track noise from the recording process. This album isn’t audiophile top fare and it is apparent, but I love it none-the-less. Aside from bringing out noise, the amp also highlighted some subtle over-dubbing on Josh Tillman’s voice on ‘run boy, run boy….’ I never noticed the layers in his vocals on that before. On Hollywood Forever Cemetary Sings (the music video is spectacular and features Aubrey Plaza of Parks and Rec—watch her), the cymbals and tambourines crash within their own violent little halos more than I’ve ever heard them. Heron 5, I dub thee the Phase King.
 

 
The Heron 5 is a truth-telling straight shooter from New York. In the classic mythology of six-gun slinging straight-talkers, this amp should really hail from The West, The Frontier, somewhere like Arizona or Colorado, or a gold panning town in the streams surrounding San Francisco. New Yorkers have no right to mete out frontier justice on my audio. When listening to vinyl rips, the vinyl is more apparent with the Heron 5 than any other amp I’ve heard, there is no doubt that your digital track came from a flawed purely analogue source, no matter how well that record was cleaned, no matter how good the recording set-up.
 
Eurythmics – Love is a Stranger is a great track for looking at imaging. The Heron 5 doesn’t disappoint. Drums are back in the deep depths of the stage, Annie Lennox seduces from up high and at the front of the stage, whilst David A. Stewart’s grunts undulate from low to middle height and from varying depths in the stage with excellent precision.
 
The spacious aeries of Kraftwerk’s Autobahn gave the Heron 5 another opportunity to be a straightshooter, this time about the limitations of the HD600. I’ve listened to the record with speakers, and the soundstage can extend up to the ceiling from my almost pension-collecting Mordaunt Short bookshelf speakers (28 years old is past most speakers retirement age).  For the first time, the HD600's stage height goes a bit higher than my head, which is truly impressive. The panning cars zoom across miles of horizontal space.
 
I found myself taking notes about the flaws in the music or the flaws in my headphones. It was especially apparent on my West German Target CD pressing of Stairway to Heaven. The track is not an audiophile track, it has compression artifacts, an elevated noise floor, and other flaws. The Heron 5 pulls no punches. The Heron 5 doesn’t force anything but honest representation of the music. It sounds natural, neutral, and transparent with precise imaging and expansive soundstage. I think that my other components (especially the iUSB3.0) help the Heron be the best it can be, but it is something special in its own right.
 
When listening to Rodrigo y Gabriela – Viking Man I was wondering who let these Mexicans in the house and what kind of beer that brilliant person wants in thanks. It was like being in the front row, while the guitars duel at breakneck speed, with the amp and headphones keeping up, never missing a beat, never smearing a string transient. If you want to blow your mind on a supremely layered percussion track, go check out KUNIKO – Xenakis IX Pleiades 1. Melanges. The track is busy as hell on a Saturday, but every element of the stage is beautifully articulated.
 
I also booted up the HD800, HE6, K1000 and ERIB-2a (review of ERIB-2a here) with the Heron all fed by a Chord Mojo connected to the iUSB3.0 with a LH Labs Lightspeed Micro USB cable and a custom made Van Damme 3.5mm to RCA cable. The Heron really lets each headphone shine. The best pairing, to my mind was the HD800. I threw City of the Sun on again, and for the first time, the haze (it has a sort of ambient feel) that is prevalent on the album was pulled back a little. Sennheiser lifted a veil.  The sound was crystal clear, the soundstage was vast (especially in width), the treble had excellent attack while sounding organic. The ambient tones from hanging transients are plucked like so many apples for Grandma’s pie. The pie is delicious and there’s no need to wait for it to cool on the window sill. With the HE6 the menace of organs on Jan Kraybill – Allegro from Symphony No. 6 in G Minor (HD Tracks 2015 sampler, which is free) is present, but the HE6 doesn’t quite have the treble clarity of the HD800 (the only mod on this HE6 is removal of the screens, a lot more can be done). The K1000 was also beautifully powered by the Heron 5. There wasn’t a headphone that sounded under-driven on the Heron 5. From memory, I prefer the HE6 with a custom made First Watt F6 30w per channel power amp fueling them (the minibeast). The HE-6 likes the extra energy. I don’t think the HD800 has ever sounded better than it sounds with the Heron 5. HD800 owners should be lining up around the block to buy this amp.
 

 
I did find some flaws with the amp, mainly related to the front headphone jacks. The labelling is not intuitive, so those who hurry to listen and don’t read the manual will likely be disappointed in what they hear. I would have rather had one well-labelled (labelled with output impedance instead of ‘low’) high damping factor output than two ambiguously labelled jacks. Both outputs buzz with low impedance headphones, this may be related to the fixed, decently high gain (12.5 dB). This isn’t really a design that makes you think: ‘You know what this big beefy amp needs to power? An uber sensitive iem!’, but it would be nice to have the option. I think having variable gain might solve some of the problem. When comparing the Heron 5 to the iFi iCAN SE, the iCAN SE did a much better job at impedance matching, but was worse at everything else (even with switches engaged).
 
Some reviewers on the tour reported volume issues with the stepped attenuator, after hearing on Massdrop that there were two versions of the volume control I asked William at Airist Audio for clarification. Apparently, the first six or so amps were made in two batches. The first batch had some units with volume control issues. All amps built after that point, including all European units don’t have a volume control issue. Speaking of Massdrop, this amp is currently live on Massdrop (3 days left at time of writing). Two more people and the price will be $749. That is a steal of a deal, and people should consider it strongly, especially if you've got an HD800.
 
Other reviewers have expressed disappointment that the amp doesn’t have a balanced output. However, the amp has single-ended internals, a balanced output wouldn’t have sounded better than the single-ended outputs the amp has. Adaptors are prevalent, get an adaptor for your balanced cable. I’ve got one, you can get one. This amp sounds better than my Pulse X-Infinity balanced out sounded, and competes with my memories of previous listening on the balanced Schiit Ragnarok with the HD600. It’s been too long since that listening session to draw any clear comparisons, but both amps are fantastic.
 

Non-audio niggles

Airist Audio is inexperienced, and it shows. When they took volunteers for the tour, they were incredibly brave. The person who was supposed to be after me on the tour was a person with 0 posts with a freshly minted join date. I was concerned that I would send off the amp with tracking and it would be to a phony address meant to steal the amp, luckily that zero post Head-Fier never responded, which might have led to my purchase of this amp. Because I was the last on the tour, the amp was going to be shipped across the ocean to Airist Audio after me.
 
I asked about buying the amp, and was offered what looked like an unbeatable price. Before I paid the invoice (I was still debating), the official price was cut in half. I don’t think economies of scale quite covers that. Beyond that they offered a CanJam discount to $850, but now have a potential $750 price on Massdrop. Not only that, but the price of shipping to the UK on their website was $190, whilst the price of shipping to the UK on Massdrop is $73. Airist Audio needs to realise that people won’t trust you if you sell them a product and then immediately lower the price.
At this point I’ll put it down to inexperience, but it is something they need to be vigilant about in the future lest they create customers who feel that Airist Audio has taken advantage of them.
 
I think if Airist Audio keeps putting out gear that is as special as the Heron 5, they have a bright future. With the new lower MSRP of $1000, I think they have a headphone amplifier that could be a run-away hit.
 

Conclusions

The Heron 5 is a special amp. It has wonderful transparency, tight natural bass that digs as deep as your headphones will go, treble that is smooth and natural without any touches of harshness, flawless imaging, and a tell me no lies injectable truth serum quality that still manages to be forgiving as it is revealing. Until the Heron 5, I never felt like I was reviewing the music and the headphones more than I was reviewing the amp when I was taking notes on an amp. The Heron 5 doesn’t impose it’s will on the sound, it is natural and neutral, the music and headphones are completely allowed to be themselves without any colouration from the amp. For these reasons I bought the Heron 5.
 
The only problem I have now, is that I feel like I need the HD800 to pair with it. That match is made in heaven, and that heaven is a Southpark heaven. Fly, Kenny, fly.
 

 
I can’t wait to see what their DAC has to offer in the future (make sure it has a pre-amp, Airist Audio).

I was fortunate to be accepted to the Heron 5 beta test group. This is one of many amazing programs that is supported only because of the proper participation of the members of Head-Fi. Thank you Airist Audio.

The Heron 5 arrived at my house in a the well protected double-sleeved cardboard box. Inside, the Heron 5 was protected with custom cut foam that adequately protected the amplifier from potential shipping damage. Given that this amplifier has been shipped to multiple locations, it is proof to me that the packaging is adequate to make sure that your purchase will arrive safely.



Included in the box is the Heron 5 amplifier, an owner's manual and a nicely upgraded power cable. Boy this amplifier has some heft to it. I added the Heron 5 to my simple setup which consists of an 11" MacBook Air feeding a Schiit Wyrd through a Grace m9xx to a modded HD 700. I connected the Heron 5 to the SE output of the Grace setting the output to a unity gain.






The fit and finish of the Heron 5 is excellent. My only nitpick is the headphone jacks which are not secured to the front faceplate. There is a little wiggle to the connectors. All the other connectors are nice and solid. I really like the large and easy to use volume control. Powering on the Heron 5 is relatively quiet and adds a subtle Amber/ red line to glow on the volume knob. This amplifier is a single ended amplifier through and through. On the input side, you can use either single ended or balanced. However, the balanced inputs are just converted back to single ended. So don’t feel if you are not using the balanced inputs you are missing anything, you are not. Out the output side, things are a little more different. There is a “High” and “Low” 1/4” plugs for the headphone outputs. The manual was kind of confusing as to what high and low reference. Is it gain? Or, was it the impedance of the headphones? After plugging into to both connectors, I liked the “Low” connector better. Your headphones may benefit from the “High” setting, so I recommend testing for yourself.




I let the Heron 5 warm up for several hours before I began my listing. Since I was way down the list of beta testers I figured it would be safe to say the amplifier has "broken in". That is, if you believe that sort of thing happens on electrical components. I do believe that products perform best when their electrical components reach their thermal stability. After warming up, The Heron 5 sounds great. The amplifier sounds quite effortless. There does not seem to be an emphasis on any particular area of the frequency spectrum. The highs are extended without sounding blown out or splashy. the mid are quite smooth. If I was going to pick on the the overall frequency balance, I would say the bass sounded a little soft or slightly mushy with my set-up. Your milage may vary. Never did the amplifier sound like it was working hard. Also, the amplifier never really got that hot.



As much as I liked the frequency balance and the effortless of the amplifier, I disliked the performance of the volume control. This is difficult to explain because I like the ergonomics of the volume knob, but, the performance is another thing. First, when first powering the amplifier on, I noticed some scratching noise when rotating the volume on the lowest three detents. This problem did seem to lessen as the amplifier warmed up. It did not go away completely. Granted, once the volume was set, the noise is not present. It only happens when going from one detent to another. Another issue to me was the volume control has bigger than ideal volume jumps between detents. There were sometimes where I couldn’t get the output I wanted. I felt like Goldilocks and trying to find the right temperature porridge. This is not a deal breaker, but I would have liked smaller jumps in output. This brings me to the biggest annoyance. The last detent. There is a HUGE repeat HUGE jump in volume on the last volume detent. From what I could tell this was around a 8dB jump! I had been playing with some equalization. As a result, the maximum gain overall was reduced to prevent digital clipping. The first time I got to the last detent it scared the **** out of me. Like I broke something. It is a definite “11” on the volume control. It did not distort, which was good, but damn, that could be a potential to damage gear, hearing etc. This should be fixed before released to the public.

Before I continue the review, I need to take a step back. I am a former product manager for an audio company. I have been involved in the development of speakers, amplifiers and processors. I was forced to believe that most amplifiers, when unclipped, sounds the same. I have taken the ABX and failed just like everyone else. I do believe amplifiers sound different in how they perform near their maximum. How they clip by running out of current or voltage the sound quality difference is obvious. It is this point that brings me back to the Heron 5. From the first moment, the amplifier sounded different. Not in frequency response, but in imaging, soundstage, space around instruments. This is not a frequency response thing but a real difference in the feeling of being there.

Up to this point in time, I just accepted that most headphones differed in width and height of the stereo image. Depth, while there, was just limited in the headphone format. Now the Heron 5 comes in and I am forced to re-evaluate. The depth from this combination is quite staggering. Sounding more like they way my Apogee home audio speakers present depth. Not depth behind but in front! This is the most impressive aspect of the Heron 5. Live recorded tracks like Cowboy Junkies - Trinity Session, or Sara Bareilles - Brave Enough: Live at the Variety Playhouse just came alive. Even studio recorded albums like Norah Jones - Not Too Late or guilty pleasure electronic music like Kraftwerk - The Mix sounded amazing on the Heron 5. With its effortless sound and amazing soundstage, I found myself listing to entire albums, just enjoying the music. Isn’t that what it is all about?

Obviously, when looking to upgrade, your audio system, price to performance does play a part in the decision making process. This is where I struggle with the Heron 5. At the original price of 2k. I would be hesitant to drop that kind of money on a single ended amplifier that does not have the features of other amplifiers. The Schiit Ragnarok is only $1699 for comparison. However, I just learned that the price of the Heron 5 was reduced to $1000. Is this a show special or the final price? If they fixed the volume control (At least the noise and big jump on the last detent), I could see wanting and recommending this amplifier for someone who doesn’t care about balanced inputs or outputs. The imaging and soundstage are that impressive.

I was part of the EU Review Tour of the Airist Audio Heron 5 Headphone Amplifier and as such had the opportunity to listen and compare this with my other kit for 10 days . A lot of listening was had during that time. After extensive and painstaking switching between this and my First Watt F6 Clone I sent the last half of my time listening exclusively to the Heron. By then I was comfortable with the differences between this and my main kit.


 


I was not aware of the Heron until I applied to be put on the review tour. In view of the price point I felt my existing equipment should be of high enough resolution to bring out the qualities both good and bad in the Heron. I came into this review with as few preconceptions as possible although being on the thread I was aware of the impressions others had. However, what is always the case is that others have neither the same equipment I have , the same music or the same ears.


 


The equipment I tested the Airist against were the best I had. I tested the Heron 5 against my finest Amplifier by a long margin - the DIY First Watt F6 Clone Power Amplifier. My friend and fellow headfier @dill3000 meticulously built this around the design offered to the DIY Community by Nelson Pass of Pass Labs and First Watt fame. Dillan has changed out some of the components in favour of some higher quality bits, all plusses for me of course. We have dubbed it "The Mini Beast" because it is huge and it is powerful. The Mini Beast was built specifically for one purpose - to slay the HiFiMan HE-6 which many of you will know needs a lot of power to perform at it's best. 


I had such good results with the HE-6 and The Mini Beast I had no particular interest in changing anything. Then my friend @glassmonkey  suggested I try the AKG K1000 Earspeakers with the Amplifier. So I am now able to bring you a review which exclusively covers my adventures with the Heron and one of the most power hungry headphones ever made - the Bass Heavy AKG K1000.



 


The Heron 5 delivers 5 Watts into 32 Ohms and has a separate 6.3 out for either low or high impedance headphones, this means your balanced cables for your HE-6 or K1000 will need the 6.3 adapter. Let me tell you right now it will drive either of these headphones perfectly well and will produce great results with them. As another teaser to the rest of this review , I preferred the sound of the Heron 5 to the sound signature of the Mini Beast. Now read on for more detailed stuff.....


 


Sound Signature of the Heron 5 compared to the Mini Beast


 


The Heron 5 has a smooth refined gorgeous HiFi sheen to the music I put through it. It was a joy to listen to any and every track. In short I loved it! Let me explain what I thought were the differences between the Heron 5 and my F6 Mini Beast. First of all - price. The F6 Mini Beast DIY build - the cost of that is a matter of a conversation between you and @dill3000 . The retail model is nearer to $4000. The Heron 5 is currently showing as $1995 on their website. The power . The F6 is designed to be powerful enough to run small to medium size speakers and can even run some floorstanders. The Heron 5 is designed to run headphones but with 5 W at 32 Ohms it will run even the most power hungry headphones that I have. The Sound - the Heron 5 has a refined smooth sound, whereas The Mini Beast has a much more lively sound signature. The power and slam of this amp is impressive. It has a crisp accurate attack. No wonder we have named it the Mini Beast!


Power and slam vs smoothness, each person will respond differently to what suits them dependent on their mood at the time their approach to music and what type of music they prefer. For the 10 days I had the Heron , I got a lot of enjoyment using my Chord Mojo as a source and had a relaxing time listening to the wonderful laidback presentation this headphone amp gave. I would be surpised if anyone who bought wouldn't feel any different from seeing this as a piece of audio kit to cherish; especially with something as difficult to get good results with as the AKG K1000s.





The AKG K1000s bass heavy model take even more volume on the Heron 5 than the HE-6 ; significantly more. However before the Heron 5 is maxed out and clipping the AKGs are singing. The difference between the K1000s and conventional headphones is that they are designed to be worn away from the ears. The further away they are from the ears the more spatial the sound becomes although this reduces the bass response. The impression is of a halfway point between the intimacy of headphones and the realism of loudpseakers.

The build of the Heron 5 is solid . It's weighty measuring almost 7 kg on the scales nodoubt due to the power supply inside the aluminium enclosure which is an elegant white appearance. There are the 2 jacks




one for low and one for high impedance phones on the front and a huge volume knob



that has a knotch adjustment that goes up in specific increments. At the rear of the unit is a metal switch that toggles between RCA in and Balanced in Mode.



It looks strange in relation to the finish quality of the rest of the Heron; almost like an afterthought. There is a 110/230 V power selector




which for my model was thankfully switched to the correct setting but at least this being user changeable can be used anywhere in the world without the need for modifying.

I have come to the end of my time with the Heron 5 and would encourage any of you interested in upgrading your headphone amp to one which can take on the best , or should I say The Beast....... to look very closely at the Airist Audio Heron 5

 
 
 
   First and foremost I must express my extreme gratitude to Airist Audio for allowing me to take part in their Heron 5 tour. This is an extremely high dollar piece of equipment and to be entrusted with such bestows me an amount of pride that I cannot be grateful for enough. However that be said with this being the super high price it is of $2,000 I will be of the up most critical of this unit. Throughout every aspect for if a company is going to present such an elite class product then I feel it should perform in representation of such. So pleasantries aside, let me put forth my review of the Airist Audio Heron 5.
 
EDIT: This product was previously rated 3.5 stars. Since Airist's recent price drop from $1,999 to $999 ($849 during their CanJam promotion period [MAR2016]) I feel it WELL performs above that price point thus my decision to change the rating from 3.5 to its current 4.5 star rating. For the hiss is very nominal but present and for those (as myself) without any balanced equipment there's no use for a balanced output jack thus only a .5 star loss in my rating choice.
 
 
 
 
 
The Opening Experience
 
    For those who follow me, rather on here or my YouTube channel, know that I’m a stickler for the unboxing experience. For to me this represents a company's “handshake” as it introduces itself to a customer. Will I be given a firm “handshake” that shows pride, confidence and empowerment? Or will I receive a timid, boring and uneventful? As with the Heron 5, unfortunately it falls pretty close to the later. Inside the very large and equally heavy box was, well another box. Inside that other box lies 2 exact cut styrofoam blocks encasing the beautiful silver Heron 5.
    On top of the styrofoam is certainly the nicest instruction manual I’ve ever seen being very thick as if every page is made from premium resume paper. That was a teaser for that was the only bit of excitement I had while opening this. I felt this was a meh, here you go. Here’s this $2,000 headphone amp. that’s simply packed in a regular cardboard box. I felt rather disappointed in the initial “handshake” I received.
 
 
      
 

 
 
 
 
 
 
 
 
 
 
 
 
 
Construction
 
    Ok, so the “handshake” was rather impersonal and uneventful so how’s the build quality? Will its construction at least impress me? Absolutely! Everything about the Heron 5 screams quality and stirness. It’s made of primarily aluminum throughout with minimal plastics. It possesses a weight to it that too states that it’s built to last, but on that same note I would take great care for it to not drop for I feel though it wouldn’t shatter it would still break, or at the very least break whatever it landed on.
    The feet are very premium. I don’t at all believe they’re just rubber stops glued to the bottom but instead true feet that are designed to absorb and disrupt vibrations and noise.
    The front has a single power button that’s the perfect amount of resistance to it as with the large and sensitive volume button. As for the outputs there are unfortunately only 2 3.5mm headphone jacks (one high and one low impedance) so for those who enjoy and prefer the balanced headphone sound, you’ll be unable to on the Heron 5. As for inputs you have a L & R channel rca input as well as a L & R XLR input. So perhaps you can still get somewhat balanced sound? I’ve unfortunately yet to hear a balanced amp. and/or headphone so I can’t give personal insight into this (anyone wanna send me a loaner for a week to change this?).
 
    
Specifications
 
    The specifications for this are a good bit detailed. Please see the attached link below for their specification page.
 
Sound
 
    So here we are. The most important part of what makes one decide how well a $2,000 amp. performs. Will this breathe unsung life into music that one’s never experienced before, or will it sound only minutely better than the current setup? Well first I feel I must disclose what I will be using for my comparison/review use.
 
-Amp/Dac combos.
    -Aune X1s
    -Audio gd NFB-15.32 w/ upgraded dac.
-Headphones
    -Sennheiser HD650
    -Bowers & Wilkins P7
    -Empire Ears Hermes VI
 
    So as you can see this is multiples higher tier than what I’ve prior experience with. At first this was a little unnerving for I am to present my finding to both the ever experienced head-fi community and my YouTube subscribers as well. But then I realized something; that’s exactly what will make this a great review. I’m going into this with open ears and an open mind and I can really have that wow moment vs. a ‘ok this compares to this feeling’. So, did I get my awe inspiring moment when I plugged this in?
    With an unresounding and unflinching scream I cry yes! The first night I had this on it couldn’t have been more appropriate. I had just finished a 77 hour work week and was exhausted, all I wanted to do was just relax and listen to my favorite songs and let myself drift away.  When there it was waiting for me, the Heron 5. I barely contained myself to do my unboxing video but as soon as I finished it I plugged my Aune in for the dac, plugged in my HD650 and then had a moment of hesitation. What would be my first song? What would I listen to to feel the first musical tone? Finally after what seemed like forever I decided upon “Pirates of the Caribbean” by Rhapsody Philharmonic flashmob. A YouTube video. I have over 2,000 songs in my inventory that are primarily lossless rips from CDs but this is the song that beckoned to me.
    Upon pressing play my eyes were immediately forced closed by a force that could only be described as unearthly. The sense of realism and soundstage was incredible. This piece is played outdoors on a sidewalk so already you have a sense of being there but the Heron just skyrocketed that. If ever there was a thought in my head that an amp. is only for making headphones louder, listening to this has completely erased that.
    For those who are familiar with the HD650 (which is likely the vast majority of you) know how impressive their soundstage and imaging is. Now I’m still a die hard believer that a tube amp is what’s best paired with these headphones but if ever you want to be transported to the performance to where positional cues are properly engineered into the audio, the scaling abilities of the HD650 brought forth so many new and smile forcing sounds I’ve never heard before. I’ve listened to this track dozens upon dozens of times but have never gotten chills as I have with the amp.
    If fact just writing this review has been delay after delay, not because of life events or long work weeks (56 during the week I had this) but just because it’s so hard to focus on anything except the experience in being bestowed. Now yes the HD650’s are amazing headphones but I’ve had them for roughly a year and listened to them through a many of amps. but this piece of art is just magic.
    And power, oh my gosh power. This art piece reminds me of the beautiful Liger; majestic rarely seen, elegant but when prompted will deliver a force that leaves the most hearty of seekers cowering. I don’t have any legendarily hard to drive orthos i.e. Hifiman HE-6 but I am quite comfortable with the volume only being at 4-5. So like the majestic Liger, be extremely wary when approaching this because if not careful, you could receive a bite that you (or your gear) may not recover from.
    So does this incredible amp. have any fault audio wise? Unfortunately yes and it is potentially a pretty darned annoying one. When I’ve my Bowers & Wilkins P7’s plugged in (the low gain port obviously) I hear the oh so irritating hiss. Now, it’s not audible with music playing but seeing this is a $2,000 amp that boasts silence I find the fact that I’m hearing hiss on my normal 22 ohm impedance. I won’t include my Empire Ears Hermes VI ciems because they’re hyper sensitivity in the grading but I will add the note that my Aune X1s has absolutely nominal hiss on even my hyper sensitive customs (which are still 17ohms). and zero on anything else I’ve ever used. Now on the brighter side, when I plug in my Ultimate Ears buffer jack the hiss is eliminated on everything minus the ciems but still for 2 grand I expect silence.
 
                                                                               
 
 
 
Conclusion
 
    To sum up my experience with the audibly euphoric Airist Heron 5 is essentially that. Audibly, it’s euphoric on high impedance headphones. The design is what I like, simplistic, professional, elegant. My only regret audibly with the Heron is that I don’t possess an equally tiered dac to complement it and allow it to spread its wings even more.
    So awe struckness aside, I will say that this amp not having a balanced output option is a huge let down. I feel for an amp. of this caliber of price to compete with the elite class market a balanced output should be a given. Also it should be dead silent, especially when that is something boasted multiple times. I understand that a 22ohm dynamic driver is quite low but still should be so sensitive to attract hiss. The 6 driver, 17ohm customs sure I’ll allow SOME leway by refraining it from the grading but it took finding one of my headphones of around 50 impedance to remove the hiss.
    Build quality is top notch and is to be expected of 2 grand as is the power output to be completely honest. For those who are in the market for an upper elite class amp. that doesn’t use balanced outputs I would greatly encourage you to look into the Heron 5.
 
Till next time my friends, also make sure you check out my Unboxing and Review videos as well!
 
 

I would like to thank the crew at Airist for adding me to the demo route. It was a pleasure meeting them at the NYC meet. This will be short and sweet...
 
Overall, the amp is excellent. It performed better in most aspects than my Benchmark DAC1, including having much more detail. It wasn't too analytical though, and it made for quite an enjoyable listening experience. The one area I felt it was sub-par in was the attack, but most people don't really care for attack frankly. I feel most people that listen to Jazz probably don't need the attack I crave listening to AC/DC, so it shouldn't be much of an issue. It wasn't bad, it just wasn't quite up to snuff. However, the soundstage was excellent. Each instrument was placed in its own little area of the soundstage, and it was really quite impressive.
 
The amp was very easy to listen to, and is an excellent product. At $2000 it may be hard to sell, simply because that's a lot of money for anyone to drop on an amp, but I feel the performance more than justifies its consideration at that price. 

Thank you to Airist Audio for adding my stop to the current tour.

Airist Audio (http://www.airistaudio.com/) is a young company now jumping into the personal audio market with their first piece of gear - the Heron 5 (US$1999) headphone amplifier. The Heron 5 is a solid state amp aimed directly at the higher end. According to their site, both its circuits and cosmetic designs reflect Airists principles - those of purity and subtlety.

 

 
 
 
 
 
 
In the 7 days I've spent with the Heron 5, I have found its many qualities are closely aligned with Airists stated design principles.
 

Temporarily stacked on the Schiit Gungnir, for reference.

 



Design (http://www.airistaudio.com/tech-and-specs/)
The Heron 5s appearance is understated. Modern minimalism. The matte silver-grey finish of the top, front and sides of the chassis is uninterrupted by any mounting hardware. The only visible screws (hex) are on the bottom and back plates. Power button (left) and volume knob (right) sit opposite each other on the front plate. The volume knobs front plate is black and the indicator glows red when the amp is operating. Though only single-ended outputs are provided (not an issue for me currently, since I'm using the stock Nighthawk cable), there are separate High and Low impedance connections.
The only other cosmetic addition is the Airist logo stamped above the power button.
 
On the back we find one pair each of RCA and balanced inputs, with a switch for input selection. A standard IEC jack sits on the right end, opposite the inputs.
 

Heron 5 rear view



The internal design is focused on signal purity, with discrete circuits for amplification and power. The signal path includes silver wire and no coupling capacitors or DC servo. A custom made power transformer and stepped attenuators are key components of Airists design. For additional technical details and specifications, use the link above.

Quick note on operation:
The amp has a soft start function, so when powered on, you'll wait for 5 seconds before it's ready to rock. The volume knobs indicator light flashes until the amp is ready.

 

Gear 
I'm running a dedicated Win10 machine with multiple tweaks to improve audio quality (Fidelizer among them), Tidal/Roon server as my software, with the Roon Android app as controller. USB (Audioquest cables) out to a Schiit Wyrd which in turn feeds my Schiit Gungnir multibit dac. I have used the single-ended (Anti-cables) connections on the Heron 5 for the entire week. Utilizing the Gungnirs multiple outputs, I was able to quickly switch between the Heron 5 and my Bottlehead SET amp. Clearly, not apples to apples. Yes...but, perspective was needed. Finally, I used my Audioquest Nighthawks (25ohm) 99% of the time, connecting them via the high impedance output jack. AKG Q701's made a brief appearance - again - this provided much needed perspective.
 
Disclosure
I admit, living solely with tube amps the past couple years, I had in mind in advance how the Heron 5 would perform.
Happily, I concede my expectations were only half right. Er, less than half.

 
 
 
 
 
 
 
 
 
 
 
 
 
For those who're done with me now...If I was to compress my thoughts into one line:
The Heron 5 is musical, quiet, powerful, refined (silver-tongued), highly resolving and smooth in its presentation.
 
Listening
I have logged about 40-50 hours with the Heron 5, so while I think we've not hit the recommended (per Airists manual) 72+hours of 
break in, allowing the amp to reach optimum performance, I can safely say I am familiar with its qualities. 
Limited time with the amp drove me to focus my listening sessions. I built a playlist (4 hours running) covering a wide array of styles and production quality.
Jazz, Rock, Hip hop, Electronic, Classical, Americana - my tastes vary.

 

 

 

 

 

The Heron 5 is dead quiet - both the signal and operating ambient noise are imperceptible.
The exception would be when turning the volume up (no music playing) all the way - there was hiss in the last 3 clicks.
I ran the Nighthawks somewhere between 10 and 11 o'clock, depending on source volume.

 
 
 
 
 
 
 
 
 
 
 
 
 
As expected, the very low noise floor allowed micro detail to float up out of that quiet space. Not something you get with  my SET amp and 25ohm headphones. Immersion is the result.

The amps ability to set the stage is remarkable. Rock solid, defined though not to the detriment of overall coherence. As time passed I chose more complex and dense recordings to confirm my impressions. On Talk Talks album Spirit of Eden, the track Inheritance is very quiet, warm, atmospheric and full of subtle musical cues. All were anchored in the recorded space, and layered in way that lent new perspective on the song.

No slouch in the tone department, the Heron 5 delivers rich tonal colors balanced by a clear mid-range.
Woodwinds have body and harmonic texture. Snare drums (initially a tad papery) have snap and body. Whock. Not whack. When appropriate, of course.

Well-recorded pianos are satisfying - the complex overtones are presented beautifully.
Nils Frahms 'Solo' record - the track Chant - the oscillation of the bass piano strings is palpable. Hammer attack is tactile.


Vocals are rich with their natural overtones. Sibilance is presented, if the recording delivers it, and I do note a touch of silvery sheen at times. This is apparent at times with cymbals too - a subtle unnatural sheen. I do feel this has lessened as the hours pass. In comparison, the SET amp delivers a touch more dimension, air, and natural tone. In trade, it's less linear and far-reaching in the frequency extremes. No surprise. These are subtle differences.

Shabazz Palaces - Forerunner Foray is a cloudy experimental hip hop track. A lot happening here, and the amp handles it with commanding bass (depth and control), clear synth textures and sparkling high end. Definitely some harshness on the backing vocals, and the Heron doesn't mask this.

Kirk Knuffke: Arms and Hands - on the track Umbrella, we have bowed upright, trumpet, and cymbals and toms played with mallets. Cymbals open up and bloom as they should. Hats have tone - not just snick. The air apparent in the space. A great example of the balanced, linear performance in the mids and upper frequencies.

Nothing's latest record isn't a great recording, but I dig the heavy shoegaze style. On the title track, guitars are well represented, and the Heron 5 manages the dense layers of distortion, cymbals and heavily affected vocals with ease. This is one loud band, and confirms the Heron 5s ability to rock balls.

Shudder to Think: Pony Express Record - X-French Tee Shirt
This is a great, though typically clinical rock recording from the mid 1990's.
The Heron 5 anchors the tune with solid kick drum and guitars.

All Them Witches: Dying Surfer Meets His Maker -
This swampy, heavy psychedelic rock bands dense guitar layers are laid bare, and the drums (over-compressed) punch and kick at chest level.
This record is muddied by lesser gear. Not so here.

Finally
The Heron 5 is a highly musical, resolving and authoritative amplifier. Staging is rock solid and balanced with a coherent delivery.
Quiet, and smooth - it can deliver the micro detail when called for, and the tone, texture and dynamics make for an engaging listen.
 
I am curious as to how well the amp pairs with high impedance headphones. And, how it compares to other solid state amps of similar quality.
I'm hoping some others on the tour will provide that insight.

 

 
 
 

 

 

 

 

Not sure if this is the amp for you? 
If you're a solid state music lover, looking for linearity and purity, and US$2000 is in your range, the Heron 5 is absolutely worth a spin.
I believe Airist Audio have succeeded in making the amp they set out to make - well done.