Audio4Soul is a small company based in Greece and they produce just two items, the Xtreme 16 (tested here) and the Xtreme 16 with USB streamer. The company has an interesting philosophy and one that will appeal to a good few people I suspect – they want to produce a straightforward product that simply allows people to enjoy theOLYMPUS DIGITAL CAMERA very best sound quality at a price point that is achievable for most people. They also recognise that not all music lovers want to have boxes and boxes of hifi equipment strewn all over their living room. Of course, having a box of tricks that does it all means you have more to spend on great quality loudspeakers and this is another important aspect of the company’s philosophy.

It’s an attractive looking bit of kit and worth noting that is it is built by hand, though I’m sure it will have its detractors – the front panel is reminiscent of a piece of lab equipment. However, there is a lovely touch on the top of the unit where the ventilation grill is a cut out in the shape of a treble clef. On the front of the unit there is an SD card slot, a power switch, a small red LED screen, a switch to alternate between optical input and coaxial and a host of LEDs to let you know the status of the machine.

So what is it exactly? With the Xtreme 16 you get a16 watts per channel integrated digital amplifier that has a powered DAC onboard with a PCM/PWM converter. You can connect a CD transport (or laptop with appropriate converter) using Spdif or Toslink (the unit uses a Wolfson 8804 receiver) or you can use the front mounted SD card reader to play Ogg. Mp3 or Wav files. Aceptable files are up to 24/96 (16/44 for the SD card). OLYMPUS DIGITAL CAMERA

Here’s what Tasos of Audio4Soul says “…there is NO dac and no amp. Its a true digital amplifier that is a “dac” powerful enough to drive speaker’s. This “dac” takes a PCM signal, converts it to PWM and then through a “low pass”filter (cutting high frequencies after the limit the designer chooses) which converts the signal to analogue it’s then directed to the speakers.” So now you know!

Out of the box it’s a pretty simple affair to set up – plug it in, wire up your chosen speakers and connect your source or sources…or not if you’re using the SD card. I chose to use a very basic, sub £50, CD transport and a laptop with a USB to Spdif converter – I also of course used the SD card. 

Immediately I thought I’d been sent a unit that wasn’t working or had been damage in the post and so contacted the manufacturer who asked if I’d turned the volume up…well of course I had!! Well no I hadn’t as the Xtreme 16 needs a lot of “turning up” before you can hear anything at all and when you turn it off it reverts back to its starting position. This is a tad annoying to be honest but you soon get used to it. You turn the volume up and down on the remote which is a nice and chunky little unit that feels very comfortable in use. You use the remote to control the source and you can mute with it too.

I’ll get another couple of little niggles out of the way before I start talking about how the unit sounds if I may. I have a god few albums I’ve ripped to FLAC so that when we have people round and I don’t have to get up every five minutes. Now, the Xtreme 16 is perfectly happy to be fed these flacs via the computer and SPDIF, but if you are using the SD card (which I was keen to do) you have to rip to WAV or OGG – great if this has been your chosen route but a bit of a pain if not. Another minor quibble is not being able to see what you have on the SD card as there is no screen to indicate which track is playing. This means that you have to scroll through the tunes you don’t want to listen to before you get to the tune that you do want to listen to. The SD card reader plays tunes in the order that they were added to the card and so the sensible thing to do would be to decide a playlist, pop it onto the card and away you go…thing is I don’t think most of us listen to music like that! OLYMPUS DIGITAL CAMERA

My main listening room is large, but having loudspeakers with a sensitivity of 95dB I thought that perhaps the 16 watts per channel would be ample to fill the room to high volumes (I do listen at high volumes and it is a very large room!!). However, listening at levels I normally would drove the amp into clipping on a good few occasions. Now let me stress here that for most people in normal sized room the volume issue wouldn’t be a problem at all, but I wouldn’t be doing my job properly if I didn’t mention it here. The solution here was clearly to spend a little time listening at what some would suggest are more reasonable listening levels and, I have to say, I actually quite enjoyed listening to the unit at these lower levels a good deal – it is detailed and articulate and great for late night listening sessions as it’s just so quiet and adds so little. In most listening rooms of normal size the Audio4Soul will be perfectly adequate in driving the room. I must stress that Audio4Soul do make a point of saying that the unit is not intended for use in large rooms and that it has been manufactured with 12 to 25 square metre spaces in mind and so I located it into a smaller room (after an enjoyable day or so at lower than usual levels in the big room it must be said) using 86dB sensitive speakers and found the unit played tunes at high volumes easily and without clipping – the reviews of music herein are all with the unit in the smaller room.

A few tunes then:

On the Massive Attack album ‘Blue Lines’ (via the laptop and using a FLAC file played on Foobar in WASAPI mode and a SPDIF converter ) the basslines, which are deep and rumbling, were delivered in a very nice, taught and tuneful manner. Vocals are reproduced fine and there is good depth and width to the soundstage. The unit is clearly very accurate and seems to add very little of its own character to the playback (see notes in conclusion) – over the last few months there have been a couple of digital amplifiers in the house and without a doubt this unit, whilst being far from the most expensive, seemed the most truthful to the original recording. Top end instruments and sounds on the album stopped and started on a pin which I liked a great deal and reverbs also ended where they were supposed to with no overhang.

Eels ‘Beautiful Freak’ is one of my favourite albums and I listen to it a great deal and here it was ripped to WAV and played via the SD card. The first thing that struck me about listening with the Audio4Soul was that the background noise was very quiet indeed  – ok I’ll be absolutely frank about this, there is no background noise from this unit at all whilst music is playing. I know this is something of a cliché, but the music does indeed come from a background that is inky-black. “Susan’s House” has a great bass line and I found it easy to follow and presented with a laidback and tight style – which is how the record has been mixed. The track “Rags to Rags” was a delight to listen to. Quiet passages in the track give way to understated but overdriven guitar and I found myself playing the track over and over with the Audio4Soul. Placement of instruments is precise and vocals a little forward in the mix – something I actually enjoy! I’d say that the Audio4Soul is very accurate in its presentation. Clinical? – perhaps some would say so, but I didn’t tire of it at all and really connected with the music – isn’t this what a bit of kit should allow? Cranking up the volume to high levels the Xtreme 16 was never found lacking in presenting the dynamics of the music. I played the same tracks via CD and found that I much preferred the presentation using the SD card as it seemed a truer representation of the recording – perhaps this is a result of using a cheap CD player and the SPDIF converter!

Time for some Gil Scott-Heron, one of my favourite artists and one with a voice full of emotion. The track “Pieces of a Man” played on WAV on the SD card was a delight! Piano was in its proper place in the mix and within its own space around it so that it was easy to follow the changes in the playing style from delicate touches on the keyboard to more aggressive chords. Decay of the notes was, as noted on previous tunes, accurate and precise. The bass line was again easy to follow and true to the way the tune has been mixed – deep enough and with an insight into the playing style and the room’s acoustics. Scott-Heron’s voice was portrayed with emotion, delicacy, and when needed, power. Again an absolute delight to listen to on this bit of kit – this is a simple tune with just piano, voice and double bass and the simplicity of the recording shines through. Soundstage is deep and wide. So again accurate and true to the original recording – a bit of a theme developing here!

Let’s have a listen to some electronic music then and see how the Xtreme 16 behaves. VCMG “SSS” is a fabulous album full of classic analogue synthesizer sounds and gives any system a bit of a work out. Here it is listened to via the SD card on Ogg file. “Spock” is a great driving track with deep basslines, electronic washes and “noodly” sounds in the background – Teutonic! Not much to say about how the Xtreme 16 performed other than all is as it should be. There is a real feel to being in front of the mixing desk, with instruments (ok noises) being where they should be in the mix and plenty of whoomf and delicacy where needed.  “Single Blip” is again relentless and with the Xtreme 16 it loses none of its head down, foot stomping, fist in the air immediacy and clout!


I could very easily live with the Audio4Soul Xtreme 16! It is tonally accurate, dynamic and a real pleasure to listen to. My preferred listening format would be the SD card, with the caveat that functionality is sacrificed in place of sound quality. Had the Xtreme 16 had some visual display of the track playing it would have been the ideal low cost all in one unit. Once you get your head around the way the unit plays back tunes on the SD card it is a simple task to make up playlists prior to a listening session. As I say I don’t think this is how most people listen to music but a small change in behaviour does reap the rewards here.

My least preferred way of listening to the Xtreme 16 was via the computer and SPDIF converter where sound quality is sacrificed for functionality and I wished I had had the opportunity to listen to the Xtreme 16 USB unit, as I strongly suspect that what I didn’t like was the converter – something I’ve noticed whilst using other equipment to the point that I no longer use this specific converter for playback.

The remote control is simple to use, the unit itself is visually attractive and it sounds great. For those looking for an inexpensive solution to listen to tunes without the need to go out and buy lots of gear, that may or may not work in synergy with each other, the Audio4Soul definitely is deserved of a Recommended award. At a price of €970 delivered to Europe and €980 to other countries I think the Xtreme 16 represents great audiophile value for money and will leave buyers able to dedicate a larger proportion of their budget to loudspeakers.Recommended 100 x 66px

The Xtreme 16 USB is available at €1320 (Europe) and €1330 (rest of the world) and the Xtreme 16 can be fitted with a retro-upgrade to include USB should you wish.

Tech Spec’

Xtreme16/xtreme16 USB

USB DAC/Amplifier (True Digital Amplifier design)

Power: 2*16W

Inputs:SP/DIF (optical and coaxial) of up to 24bit/96Khz data rate, USB asynchronous

of up to 24bit/192Khz. Providing driver for Windows platform (only on USB model).

SD card player: SD card up to 16GB (8GB included with SD to USB adapter)

and data rates of 16bit/44,1-48Khz (.WAV) and 128Kbps-320Kbps (Ogg/mp3).

FAT 32 system for the SD card.

THD+N:0,01% (1W, 1Khz)

THD+N:0,1% (Full  power 20hz-20Khz)

Remote control (hand made).

Dimensions:360x145x275 (L*H*D)


Author – Stu

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