Who are Just Audio?

Just Audio is the brain child of Justin Harris, an experienced electronics/embedded software engineer with a love of Music and Hi Fi, whom previously has worked professionally in the mobile/wireless devices product creation domain. His passion is infectious, he obviously relishes the chance to talk about his ideas, electronics in general and getting the very best out of Hi Fi gear. Justin has worked for some of the mobile phone manufacturing giants, you may even have some kit he was involved in already.
“This all started with designing some functionality to incorporate into my modified Quad 405 power amplifiers, to enable standby and best in class audio detection and wake-up functionality, with the intention to make this in such a way that it could be retro-fitted without making a mess of the existing internals. ”

It was a desire to get the very best of his own Hi Fi kit which lead to the ground up designs for the uHA-120 and now it’s Class A big brother the AHA-120.

In 2009 he decided to start his own company. “The main theme originally was modularity and utilisation of surface mount technology to enable making the modules small enough to fit in tight spaces. I wanted to make operation seem natural and intuitive to the end-user and perform better than other implementations that I’d experienced myself.”
Having such a strong engineering background seems to have provided Justin with an understanding that  individuality, through modularity and customisation, will develop products with the end user always in mind. It can take a long time to find the bit of kit which has all the required abilities and compliments existing headphones or source. By understanding the wants and needs of the enthusiast he hopes to be able to bridge these difficult gaps for customers whilst keeping an eye on the shifting sands of the audiophile landscape.

“By early 2010 We had started to think along the lines of making a complete product that could be tested to the relevant standards. We had already built up a library of components and a capability to produce electronics modules. I’d been studying on various audio amplifier topologies and experimenting with my own Hi-Fi system at home, attaining both measurable and perceivable improvements. I’d also been looking at headphone amplification projects and products out of passing interest for some time and had already built my own headphone amp for use when I was working at the office. The idea occurred too me, why not use the technological advances to make a pocket sized headphone amplifier more akin to the standard one would expect from a respectable desktop amplifier. Of course, the idea of creating a pocket sized amp isn’t new, but we noticed that everyone in this market seemed to be just using an operational amplifier or some form of dedicated amplifier IC combination. Coming more from a Hi-Fi power amplifier interest area, we felt that using a commercial IC would never provide the same level of audio quality as a carefully crafted discrete circuit, so I set about building some prototypes of more discrete topologies usually found in larger power amplifiers. A few months later we had determined most of the system level components (battery, charging, connectors, volume control pot), along with a hybrid class AB topology that we had built in enough flexibility to fine tune and provide what I felt is a more High Fidelity sound, yet able to operate from a low voltage power source.”

With a direction that many enthusiasts will recognise Justin is still committed to customisation and the minor adjustments that provide the best possible performance. So far he has carried out many mods working closely with customers requirements. Several such projects have seen him build a range of Studio quality cabling and adding mods to hardware which have helped  him shape the future direction of the Just Audio range and additional services. More about Justin’s big plans for the future of Just Audio and functionality upgrades (which will be available for existing Just Audio amp owners too) later on.

AHA-120 Put To The Test

Having a Pair of  the truly excellent Beyerdynamic 600ohm Tesla T1 Headphones at my disposal, Justin suggested he send me the Just Audio Class A AHA-120 to test. Quite a few manufacturers have products in this small niche market, some fail to deliver improved sound quality or improved player usability with hard to power headphones, Justin expects the AHA-120 will be a great match to the T1’s. I have been using the excellent iBasso D10 with headphones regularly and also other acclaimed portable amps for some time now, this will be the first proper portable test with the Beyer T1’s.

Many audiophiles believe that class A gives the best sound quality with its absence of crossover distortion and reduced harmonic distortion. Class A amplifiers are typically more linear and less complex than other types, but they are very inefficient. This type of amplifier is perfect though for driving sensitive low distortion headphones where the listener wants the very best audio quality, without the massive electricity bill potential of a full sized class A HiFi system at home! Operating in class A means that the amplifier is always passing current through upper and lower sections of the electronics even when there is no signal, negating any artifacts as a result of the transistors turning off and back on again during the amplification process. The Amp arrives in it’s plain box  - usually an exciting sign. Inside the box there is bubble wrapped AHA-120, a mini usb cable and four self adhesive stick on feet. Inside the bubble wrap bag with the amp is a silica gel sachet, included to prevent any moisture in the air from condensing and damaging the product. Removing the amp from the bubble wrap bag it becomes clear that extruded aluminium case is flawless with a soft anodised finish, and ultra fine print on both the front and rear panels. The company logo on the front panel is in colour and the serial number on the rear panel is engraved, which is a nice touch. The version I have is a product sample and is already burned in.

I can’t resist turning the large volume knob, switching the unit on revealing two things - a warm Amber glow from the LED and the silky smoothness with which the volume turns. The Aluminium case with soft anodised finish is solid and picking it up the unit weighs neither more nor less than expected - it is a little large though compared to most portable amps (26mm x 80mm x126mm, the uHA-120 is much smaller - 23mm x 52mm x 85mm) but still has a very small footprint when used as a desktop amp. Print work is detailed is flawless with all controls well labelled, panel fixings appear to be stainless steel. At the front, right to left, you have the chunky volume knob with accompanying Amber on/off LED, next the 3.5mm output then the input and finally a five-way selector nob for impedance matching your headphones. This feature is probably more accurately described as class A biasing level, most users would like to match current setting to  their headphones, this is simplified by just providing a selector for selecting the amount of bias needed to maintain class A operation for a given headphone impedance. Without this feature the battery would apparently only last around 18 hours whereas now you can get up to 60 hours of battery operation when driving 600 ohm headphones. Round the back there is an engraved serial number, USB charging socket and red to Green Charge LED and two small charging operation switches for charging management with other USB devices. The AHA-120 contains a Vishay P11 potentiometer mounted on a solid ground plain PCB, low ESR Capacitors, Burr Brown Opamp to provide a FET input stage and Alps switches. The flat front panel sockets feel rather nice and connection seems very solid and reliable with a very positive feel to the connection.

The first device I connect to the AHA-120 is my iPod touch via an iBasso CB07 pure Oxy sealed LOD cable, I plug in the Beyer T1’s and turn the five-way switch to 600. Firing up the first lossless track, Radiohead - Pyramid Song, I am instantly impressed with the balance of weight and air, there is an instant feeling of synergy between amp and headphones.  As the song unfolds I find myself closing my eyes and feeling my way around the stereo image. There is real texture to the sound which is vivid, heavy and fluid - detail is is apparent but subtle giving structure and very accurate movement to each instrument. The piano in this track is distractingly pretty and I am already excited to try plenty of other favourite music. There is a ton of headroom and I never get the white marker on the volume control much past 12 o’ clock.The iPod touch is surprisingly charged twice in two days before the amps lithium polymer battery runs flat, which I had not expected at all. It isn’t the best I’ve heard from the T1’s, but the iPod is the most likely culprit and I will put that to the test next. After a decent couple of hours with this initial setup I connect the AHA-120 to the analogue outs on a broadcast quality sound card (running .WAVs from a Mac Book Pro) and revisit the first track I heard. Within seconds I’m glaring at my iPod and shaking my head in disappointment as if it had just kicked a football through my kitchen window. This shows the pairing has real merit, as inferior sources are often shown up by a great headphone/amp combination. The sound is more lush with even more realistic texture and structure, solid and powerful but lighter, quicker. I run through a few classical favourites (this is, to date, the best I have heard Prokofiev’s Piano Concerto No2) and the first bad thing I think is when I realise that I have to give the amp back. It follows me everywhere with the iPod touch, great results with Ultrasone Pro 900, Beyer DT770 and DT880, Sennheiser HD650 and HD600 and fantastic in 32ohm mode with my Grado 325is, until sadly it has to go back. Just Audio have a balanced configuration ,using two AHA-120, which includes either balanced XLR or Jack output into the amps and a HD650 balanced cable. Justin expects Beyer T1 and Sennheiser HD800 users will be interested in a cable mod or replacement cable to use this configuration too.

The AHA-120 is very accurate but has a lush warmth which adds to its very real sound. It seemed to encourage the already super clean Beyer T1’s to find convincing sculptural depth in some quite difficult recordings. As promised Just Audio seem to have built a portable Class A which can contribute the power and finesse needed for high impedance, flagship model headphones.

Future Just Audio Projects

Just Audio have some exciting projects under way. They are currently designing a very forward thinking DAC which may be modular, new Balanced operation cables are available now with more cable variants to come and Balanced amps may eventually appear. Due to customer demand some iPod modifications may be added to their service repertoire and customisation of Just Audio amps will continue to be carried out for the best possible operation with specific headphones. Thanks to Justin for talking to me, the loan of the AHA-120 and for the use of the Photos.

Just Audio at Head-fi Meet

Just Audio will be attending the London Head-fi meet where you can try the AHA-120 and uHA-120 for yourself and pick Justin’s brain about his approach to Audio Design. He will be there with another of our favourite HiFi people, Mark Dolbear who will have the latest HiFiMan HE-5LE and HE-6 and Schiit Audio amps on display and for you to try.

More Information

More information on the full range of Just Audio Products can be found here.

At HiFi Headphones we’ve just taken delivery of our first batch of FiiO headphone amplifiers.  The brand new FiiO E5 and FiiO E3 are ultra small headphone amplifiers with a price tag that makes them affordable for anyone with an iPod, MP3 player, laptop or mobile phone.

The FiiO headphone amps promise increased output power (to power hard to drive headphones), added bass response and even better clarity of treble notes.

FiiO E3

The FiiO E3 headphone amp is the perfect introduction to improving your portable audio setup - look out, it’s a slippery slope! :)  At a price point that makes it possible to try without risking to much cash, the E3 has taken the headphone amp World by storm.

Just connect the FiiO E3 between your portable audio device (iPod, iPhone, laptop, mobile phone, etc) and enjoy the improvement in volume and sound quality.

FiiO E5

The next step up from the E3 in the FiiO line-up is the all new FiiO E5.  With an exterior casing that has been redesigned to fit more comfortably in the pocket, and internals completely revised to improve noise figures, the FiiO E5 is a force to be reckoned with.

When compared with higher end headphone amplifiers, such as the iBasso T4 or Graham Slee Voyager, the FiiO E5 does colour the sound to some degree (it definitely warms up the bass response), but with the FiiO E5’s price tag of less than £25 I shouldn’t really be comparing.

More Information

For more information on FiiO Headphone Amps, a range of other Headphone Amplifiers & DACs and iPod Line Out Docks (LODs) please visit the HiFi Headphones shop.

If you’ve been following the world of headphones you may have noticed that headphone amplifiers seem to be cropping up more often than ever, but what’s the point?  Do they just increase volume, or is there more to it?

Below are a few good reasons to upgrade your audio setup with a headphone amp.

Ability To Power ‘hard to drive’ Headphones

Some headphones are notoriously hard to power.  A headphone amplifier gives your audio source a boost in output power, which gives the headphones a more full sound, improves bass kick and often makes trebles more defined.

For example the Sennheiser HD650, HD600, HD595 and many Beyerdynamic headphones have relatively high impedance ratings, which mean they need more power than most to drive the headphone speakers.

Interestingly, many lower impedance headphones and earphones (normally the high end models) also appear to benefit from the use of a headphone amplifier.  For example the low impedance Grado GS1000 or Grado RS1 can be easily be driven by a humble iPod, but add a headphone amplifier such as the Grado Slee Solo to the equation and the improvement in sound can be very satisfying.

Avoiding Cheap Headphone Outputs

The headphone output on many portable audio sources, such as iPods, iPhones and laptops, can be very poor indeed.  The electronics used often leave much to be desired and are obviously designed with budget, rather than sound quality, as the major design factor.  A headphone amplifier offers ways to avoid the noisy headphone output completely.

The iPod and iPhone headphone socket can be avoided completely by using a Line Out Dock (LOD) cable.  These cables take the un-amplified line out signal from the 30 pin dock connector provide a way to drive a headphone amplifier with this better quality signal.

Laptop and computer owners can avoid the often breathtakingly bad headphone output with the addition of a Digital to Analogue Converter (DAC) and headphone amplifier.  The DAC is connected to the computer’s USB port and the conversion to analogue audio signal is done well away from the noisy electronics inside the computer.  Some products, such as the iBasso D2, combine a DAC and headphone amp into a single unit.

More Information

For a full range of headphone amplifiers & DACs and iPod & iPhone line out dock cables (LODs), please visit the HiFi Headphones online shop.

FiiO and KS Distribution today announced a partnership for distribution of FiiO’s audio electronics products in the UK.  Based near Brighton on the South Coast of England, KS Distribution is a specialist distributor of headphone and earphone related audio products.

KS Distribution is to be distributing FiiO audio electronics products to independent specialist retailers in the UK and Ireland.

FiiO headphone amplifiers provide a way to get the best audio performance from portable audio sources, such as MP3 players (Apple iPod, iPhone, etc) and laptop computers.

The FiiO E5 has taken the headphone amp market by storm, with a high specification and entry level price making it accessable for anyone looking to upgrade their portable audio system.

About KS Distribution

A leading audio electronics distributor, KS Distribution specialises in bringing innovative products to the UK market and providing a World class service to their customers. Offering a carefully selected range of products for home and mobile listening, KS Distribution are a highly focused team whose primary aim is to develop strong partnerships with retailers and manufacturers.

For more information visit www.ksdistribution.co.uk

About FiiO

FiiO Electronic Technology is a personal audio consumer electronics manufacturer with a product line-up that includes headphone amplifiers and speaker systems.  Leading the field in affordable personal audio products, FiiO is constantly innovating to stay ahead of the competition.

For more information visit http://www.fiio.com.cn

There are other models in the range, including an ultra portable headphone amp called the iBasso T4 (it is VERY small and weighs just 29 grams) and a high end model that comes with various types of Op-Amp to swap over to alter the sound signature (one for the perfectionists).

The iBasso D2 works especially well with higher impedance earphones such as the Sleek Audio SA6 and Klipsch Image X10, where there is good improvement in depth of bass, as well as high frequency detail and soundstage. I’ve yet to test with lower impedance earphones (Ultimate Ears Triple.fi 10’s, etc), but I would guess the effect is similar, but maybe not so pronounced.

Below is a photo of the iBasso D2 with my Sleek Audio SA6’s and an old iPod Nano:

In my opinion the most interesting application for the iBasso D2 is using the DAC with a laptop. With my IBM ThinkPad T62 laptop feeding the D2’s DAC and a pair of Sennheiser HD650’s the difference in overall sound quality is significant compared with the laptop’s standard headphone output. I would say this is the application where the biggest improvement in sound quality is seen.

More Information

For the range of iBasso headphone amps, including the iBasso D2 and iBasso T4, please visit the HiFi Headphones shop.

These very well made units from Pro-Ject Audio, an Austrian high end audio manufacturer, really do sound superb. Pro-Ject’s headphone amps are ideal for driving high quality dynamic Hi-Fi headphones.

With RCA phono inputs these headphone amps are ideal for connecting to TV’s or home cinema amplifiers, where a line level output is available.

Pro-Ject Head Box SE II

The dual output headphone amp from Pro-Ject is perfect for setups where you need to drive two pairs of headphones with independent volume controls.

The Head Box SE II is the second generation in this model from Pro-Ject. Featuring a completely revised internal circuit board, this revision offers a fuller sound, with plenty of bass kick and high end detail. The build quality has also improved, making this a very robustly built little box.

Featuring two independent high resolution volume controls, the Head Box SE II is an ideal headphone amplifier for good quality Hi-Fi setups, home cinemas and computer based audio systems.

Pro-Ject Head Box SE II in Silver

The Head Box SE II is available in Silver or Black.

A typical configuration for the Head Box SE II is a home cinema setup where the output from the DVD player is routed across the room to the Head Box amp (via high quality interconnect cables). The Head Box SE II can be located near the seating with each listener having their own independent volume control. This setup is great for late evening film viewing where you don’t want to annoy the neighbours or wake the children!

Pro-Ject Head Box II

The Head Box MK II is a single output headphone amplifier with the same high quality construction and superb audio quality that the Head Box SE II offers.

The Pro-Ject Head Box II is a very nice little unit and has been award 5 Stars by What HiFi? Sound & Vision - see Pro-Ject Head Box II Review.

The Head Box II is ideal for computer audio setups, or where only a single headphone output is required in a Hi-Fi or home cinema setup.

Project Head Box MK II in Silver

The Head Box II is available in Silver or Black.

More Information

For more information on Pro-Ject headphone amps or headphone amplifiers from other brands such as Graham Slee, please visit the HiFi Headphones store.

John Cadman, Graham Slee’s production manager, reported that the delays have been caused by a shortage of the Voyager case component. The case is manufactured outside the UK (in Canada) and the shortage of this one component has held up production.

About the Voyager

Graham Slee produced the Voyager headphone amplifier to be used with MP3 players, such as the iPod, and other portable audio devices. The Voyager amp simply plugs into the headphone output of the audio source and you plug your headphones or earphones into the Voyager’s headphone out.

Alternatively the Voyager can be connected to an iPod with a cable that connects directly to the iPod’s dock connector. This setup provides a better quality line level signal than the headphone output socket.

About Graham Slee

Graham Slee have a long standing reputation in the British audio world for producing phono pre-amplifiers (for vinyl record playing turntables) and high quality desktop headphone amplifiers, such as the Graham Slee Solo.

The Solo headphone amp is popular in broadcast and recording studio environments. The Voyager is the first venture into portable headphone amplifiers for Graham Slee and has been very well received by the audio and HiFi press.

More Information

For a range headphone amplifiers, including the Graham Slee Voyager, please visit the HiFi Headphones store.

Graham Slee Voyager - Give your iPod a high quality audio kick

The incredible sounding Graham Slee Voyager iPod headphone amplifier is now available from the HiFi Headphones store.

If you appreciate high quality audio and feel that listening to your iPod is a bit of compromise, then the British built Graham Slee Voyager Headphone Amp is an ideal solution. As most high end audio enthusiasts will quickly tell you, the iPod’s headphone output is actually pretty bad at driving many headphones. The Graham Slee Voyager gives an iPod the extra grunt that enables it to easily drive high quality headphones, such as the Sennheiser HD650, with added warmth and fullness and without distortion.

As well as allowing the iPod to drive higher end Hi-Fi headphones, the Graham Slee Voyager is a also perfect for driving lower impedance earphones and headphones. The Voyager headphone amplifier features a contour switch to equalise street-wear headphones, emulating the sound you get from “home” or Hi-Fi headphones - putting back that missing bottom-end bass and replacing the usual scratchy highs with the whole clarity that makes this portable headphone amplifier “hard to switch-off”.

About Graham Slee

The Voyager headphone amp has been developed and produced in the UK by the team at Graham Slee based in South Yorkshire. Graham Slee have a long history manufacturing high end phono amplifiers and headphone amplifiers. The Graham Slee Voyager is their first step into the world of portable audio, but this is fast becoming a major part of the business.

More Information

For more information check out the Graham Slee Voyager Headphone Amp and a range of other high quality Headphone Amplifiers at the HiFi Headphones online store here in the UK.