[Listening test] Wyred4Sound mINT Integrated [English]

Wyred4Sound Mini-Integrated Amplifier

Worth a mINT?

Product name: Mini Integrated - mINT
Manufacturer: Wyred4Sound - USA
Supplier: Item Audio
Cost: 1300UKP. (Currency conversion)
(YMMV)
Reviewer: Andy Norman - TNT UK
Reviewed: September, 2012

Introduction

Wyred4Sound (I'll use W4S for short) is a young company from the USA. It grew from a sideline of a couple of employees of Cullen Circuits who started modifying kit at work then, using the knowledge they'd gained, to design and build their own electronics from scratch. Now the business is growing by serving the migration of hi-fi towards computer based systems. The W4S product line is based accordingly around high quality digital to analogue converters and high power pre and power amplifiers.

Following their taste for quirky product names, mINT is short for "mini integrated" - which is just what we have here - a 100 watt integrated amplifier with a built in DAC, in a half sized case. So you can just hook this unit up to a computer and a pair of speakers and away you go. It doesn't get much simpler. Often though, when manufacturers bring together different elements into the same downsized unit, it can be at the cost of reduced quality. So we set out to find out if that applies here.

What You Get

Sometimes I look at photographs of the inside of hi-end hi fi (….sad I know…). What I see is a big box with a transformer, a couple of circuit boards and a handful of components. Not with this baby. It's crammed. It's a major engineering design achievement just to have managed to squeeze so much into the box never mind getting it to work.

Starting from the front end, the DAC is based on the same ESS Sabre technology as W4S's stand-alone DACs (though using less chips than their high end models). The DAC will take and switch between three independent inputs - coax, USB and optical. Moving to the preamp stage there's also a line input and two further - configurable - sockets. Using a button on the rear of the unit one of these can be configured as either a variable or fixed or level input (the latter for home theatre use where volume is controlled by the HT receiver). The other socket can be configured between a variable preamp out, typically for a powered subwoofer, or a fixed level output (effectively an output for the DAC). Then the power amp stage delivers 100 watts of clean power. This structure gives a good deal of flexibility allowing the individual elements of the unit to be used separately, offering an upgrade path or reuse in different configurations. The only slightly surprising thing, given current trends and the likely target market, is that the unit contains neither a wireless or direct IPod connection. Given that W4S also market a network player which would pair up well with the mINT then I guess that keeping it focused on the core functions makes sense.

Specification

OK, let's look in a bit more detail.

The DAC is driven by an ESS chip. The marketing material says it uses the same technology as used in DAC1 and 2, which is true but overlooks the fact that it uses a reduced number of chips in the conversion. So you're not getting a DAC 1 in the box although the DAC stage is available separately (as the £350 W4S micro DAC). Having said that, in the mINT the DAC benefits from a better power supply than the micro DAC so I'd expect the sound from the integrated to be a little better than the stand alone.

Channel "tracking" (presumably separation) for the DAC is specified as +/- 0.015 decibels. Frequency response is flat to 0.045db between 20hz and 20khz. Which is all fine, except I find specifications on DACs really don't seem to have much bearing on how they'll sound. The amplification stages use Bang and Olufsen "ICE modules" in common with W4S's larger amps. Strange – and strangely impressive - to think that B&O, a company I had always associated with overpriced lifestyle systems, has come to be a leader in digital amplification. These Class D modules deliver 100 watt per channel into 8ohms. The implementation here gives the lowest specified distortion of any other W4S amplifier. So, for example, the mINT running at 10 watts suffers 0.004% distortion compared to 0.008% on the 1000 watt monster. The mINT also offers the highest dynamic range - 119db compared to 115db for the 500watt model. The bottom line is that this is a very powerful and capable amplifier despite the small form factor. It is comparable to the (themselves well specified) bigger amps in virtually every performance characteristic except brute power.

Then there's a headphone amp. This is specified to drive headphones of up to 600ohm so should work well with virtually all models. Plugging in headphones mutes the speaker outs. The specification is given as 720mW into 32 ohms at 0.1% distortion which strikes me as a slightly low output and high distortion figure (compared, say, for example to the Musical Fidelity X-Can v8P which claims 1.3 watt and 0.008% into 32 ohms). In listening tests with a couple of pairs of headphones though there was no hint of distortion and the headphone amp performed very well.

I think a picture starts to emerge that this is not a poor cousin to the separates in the W4S range. Attention to detail in the design continues with the volume control. This is a resistive ladder rather than a conventional pot and the volume knob on the unit acts only as a position reference – the signal does not pass through it. Although this gives the knob a slightly unusual feel it works well and does mean the control preserves channel separation and is very linear. In any event, controlling the volume is likely to be done via the remote control.

A plastic "stick" shaped remote is provided with controls to switch inputs, control the volume and mute the device. I was pleased to find that the remote control is very easily usable – it's not fussy about angle of acceptance and worked consistently well throughout the review period. A really nice touch is that muting and unmuting cause the volume to fall or rise smoothly to and from silence over the course of maybe half a second, rather than instantaneously. It's rather like the feature in luxury cars where the interior lights fade in and out rather than switching straight on and off when the doors open and close. It's not a major feature but it does show the type of attention to detail that you might expect from a piece of hi fi that, whilst very economical in high end terms, costs more than the vast majority of the population would ever think about spending on a hi-fi.

Material Quality

The impression of quality continues with the grey aluminium casework. It feels very solid and professional. The hardware is good, the speaker terminals in particular being very substantial. The aesthetics may not be to everyone's taste though. It follows the W4S house look of a grey aluminium case with black cheeks but whereas on the big amps this looks OK, the cheeks appearing to cosset the body of the electronics, I think it makes the controls look crowded in the centre of the mINT. It doesn't affect the functioning, and the cheeks are used to house the on/off switch on one side and the headphone jack on the other, but the look is best described as professional rather than luxury.

Installation & Set Up

It's a box. You plug it into your speakers and your source and that's it – or at least it should be. To get asynchronous USB you need a dedicated driver. I gained a false sense of security when this downloaded and installed in minutes on the Windows XP netbook that feeds my main system. I was also struck by how much better the asynchronous link sounded so, when I moved the unit to my study to spend some time in my second system, the first thing I did was to download the driver. Then I spent a stack of time, and half dozen emails to Clint at W4S, trying to get the unit to work with my Windows 7 64bit machine. Eventually I tracked the problem down to the driver being unsigned and Microsoft trying to protect me from using it. Either way, after I'd loaded the driver once, having overridden driver signature enforcement, it worked without issue. Clint assured me that there is a stack of these units in use around the world and this problem hadn't arisen before although he took the problem away to double check. Software conflicts are a perennial problem with complex operating systems and, unfortunately, a willingness to track down issues can sometimes be a cost of using computers for audio.

Listening Test

First off I tested the mINT in my main system. This means it was fed initially by a simple netbook with the USB converted by a KingRex UC 192 USB to Coax converter. The outputs of the mINT were then connected to Usher Be-718 loudspeakers. The speakers are fairly revealing and difficult to drive so set a stern test for the little amplifier and DAC combination. My first impression was that the sound was clear but a little thin and bright. That impression lasted only as long as it took me to download the USB driver and connect the USB direct to the mINT. The change to a direct USB connection immediately brought out the qualities that I remembered from the DAC2 that I reviewed last year. The bass gained immensely in presence, detail and pace and the top end, whilst not the richest (there is no hint of valve-like presentation here) became more detailed and sweeter in tone, losing a slight dryness I thought I'd found via the converter.

The review unit I was using already had some hours of use on it so did not need burning in. Anyway, I left the mINT in the system for a few days and listened to a broad range of material. I found the sound to be very consistent with different genres. The best word I can find to describe the sound is just "clear". Imaging and instrument separation are very good. Transients appeared suitably fast – evidenced by the presentation of piano (using my favourite test of this, the 2004 album "Baroque Reflections" by the Italian pianist Alessio Bax). Bass remained a strength, with similar qualities to the DAC2 that I reviewed last year. The bass is deep and detailed but remains well controlled – without boominess. So, for example, listening to Boy in the Bubble from the Paul Simon album, Graceland, on its 25th anniversary, I was reminded of how well the bassline really drives it along. At the same time the percussion parts were picked out clearly and vocals sit tidily in the mix rather than being thrust forward.

While I was reviewing the mINT I was lucky enough to attend Paul Simon's 25th Anniversary concert to mark the release of that album (can it really be so long...). It was a great night which also featured Hugh Masekela. Masekela performed his great protest song, "Stimela (the Coal Train)" but, to be honest, it fell a little flat in the context of a huge outdoor gig. So I went home and listened to an old recording of the same song via the mINT and it really delivered. It's a long track that majors on dynamics – with loud drum crescendos and soft guitar passages. Clarity in the detail delivered the atmosphere of the live recording and beautifully rendered the electric bass textures beneath the entry of Masekela's trumpet. Overall the mINT made light work of the dynamics, staying clear and unruffled and delivering the musical experience in a way that the live concert had failed to do.

I find classical voice a good test of a system and often play the sublime Anna Netrebko's rendering of "E Strano" from La Traviata (Sempre Libera, HD Tracks). The mINT's high definition delivered a convincing image of her magnificent voice in an opera house space. I was slightly less keen on its presentation of orchestral strings. With strings, I felt a slight lack of warmth may have been holding back a full involvement with the sound. I checked this further with the magnificent, closely mic'd, recording of Vivaldi's Four Seasons by the Venice Baroque Orchestra (Guiliano Carmignola 1999). But the level of detail, say on the cellist Steven Isserlis's 1997 recording of compositions by the modern English composer John Taverner (not, incidentally, to be confused with the early composer of the same name) overcame any reservations I may have had.

The limitations in terms of string tone reflected a slight mismatch with the Ushers. Such inefficient speakers really need more electricity thrown at them to really sing. My normal amplification delivers 300 watts and that gives a thoroughly different experience. The W4S did however give a pretty creditable performance but it's not a combination I'd recommend.

The reservations I'd had about a slight lack of warmth fell away when I moved the mINT into my other system. Here I was asking less of it in terms of drive. I hooked it up to my Acoustic Energy AE509s that are 91db efficient, a far cry in practice from the (optimistic) 86db rating of the Ushers. The mINT rewarded me for this relaxation with a great step up in sound. The SPDIF input, fed optically from an Asus Essence soundcard, still sounded a little cluttered, as it had through the Ushers but it was not thin as it had been before switching inputs previously. Once I'd overcome the software problems and was able to move again to direct USB input the sound again came to life. The switch caused the soundstage to open up and the detail was tremendous, even in a smaller room. The first thing I listened to on this system was a BB King greatest hits collection. Lucille sounded so sweet. Then onto a 24-96 edition of "When I Look in Your Eyes" by Diana Krall. I was struck by the depth of the reverb and the tight, but richly detailed bass. This would be a great amp for bass fans! I really enjoyed the double bass intro to "Use Me" from the old audiophile favourite Patricia Barber's album Companion. The treble remained clear and open without feeling analystical and the mid-range was very natural. A few examples included the old Joe Cocker classic "Delta Lady" that I'd not listened to for ages. The piano tone was really natural and the detail brought out the rasp in Cocker's voice perfectly. The chorus, with its backing vocals was little harsh but I suspect that's the recording. A complete change of style to Dick Hyman's "From the Age of Swing" brought the unit's strengths to the fore. Double bass was deep, tight and detailed. Piano tone was rounded, percussion crisp and metallic where it should be. Altogether enough to cause me to drift off from review mode and into the music. Always a good sign!

Finally, I listened to the headphone amplifier. Not a lot to say really – it struck me as clear, realistic, and satisfying. A good addition to the package. It possibly falls a little short in theory compared to a stand alone headphone amp but it sounded just fine to me. Headphone nuts could always used the fixed output to incorporate a separate amp but most people will find that unnecessary.

Conclusion

The mINT seemed to me a really well-balanced combination. There was a synergy between the rich tonality of the DAC and the refined, detailed presentation of the amplification stages. When I listened to each stage separately I was still impressed, but slightly less so. The result is definitely greater than the sum of the parts.

Then there is the question of value and comparisons with alternatives. Powerful digital amplification is fairly expensive and, as an introduction to that technology and its associated fast clear sound this is pretty economical, compared, say to Bel Canto or PASS Labs. This combination delivers a huge chunk of what is good about the W4S house sound at a relatively reasonable price. Of course, it is possible to put a system together for this money which may compete on quality with the mINT but I think it would be pretty challenging, especially when you consider that there's not even any need for interconnect cables with the unit. And obviously its great if you're pushed for space. So in summary, the sound is agile, clear, direct and to the point. It's not for you if you want a complicated system or an overtly sweet, valve like sound. Apart from that I felt you can't really go wrong: it works well, sounds great.