Micro iDSD Black Label: A Different Flavor of Review

[sdolezalek]

The iFi Micro iDSD Black Label is a tremendous value in a portable DAC/headphone amplifier that also very capably doubles as a DAC in a high-end home audio system.  I recently had the pleasure of having two weeks with this DAC as part of iFi’s World Tour (that lends out some of its new products to a few lucky regular audio consumers like me). 

 

There are numerous reviews of the Micro iDSD BL as a DAC and headphone amp; almost all saying its audio capabilities far its exceed its very modest roughly $500 price point.  I don’t want to repeat that other than to say I wholeheartedly agree with the rave reviews it has received.

 

Instead, I’d like to talk about how the Micro iDSD BL can serve as a great way for computer audiophiles to get the most out of a combined hardware/software combination that maximizes the Micro BL’s sound capabilities and lets you, the user, fine tune exactly how you want your DAC to “sound.”

 

Arguably, we don’t want the Micro iDSD BL, or any other DAC, to sound like anything.  It should just be “transparent.” What you will learn is that in reality transparence comes in many flavors.  The big difference is that the combination of the Micro iDSD BL and computer audio software lets you, the user, choose the sound that is most “transparent” in your room and for your system. 

 

The truth is that what goes on in the D/A (digital to analog) transformation always has an influence on the final sound (MQA is trying to build a big business on that proposition).  By definition, the D/A conversion process involves tradeoffs that tend to pit linearity in frequency response versus accuracy in dynamics (or timing response), among others.  Typically, the DAC designer makes those choices for you and you get to decide (at the time you make the purchase) whether that set of compromises is best for you.  Unfortunately, you are typically forced to make that choice listening to your dealer’s system in your dealer’s room – not your system in your room.    

 

The Micro iDSD BL provides a very affordable way to fine tune your DAC to your system in your room, including any future updates you make to system or room.  How does it do that?  It does that by interfacing with a set of affordable software tools that allow us to choose a) the resolution of the music stream b) whether we use a PCM file or a DSD file, and c) what software filters we apply.  Those software tools include HQ Player, Roon, Audirvana, Foobar, JRiver MC, Amarra and others.

 

There is endless debate on whether the standard 16/44 redbook CD format suffices to give us audiophile quality sound, or whether we need DSD64 (the standard SACD format) or even higher resolution (i.e. PCM 24/192 or DSD512) files and whether there is a difference between them we can actually hear.

 

I’m not addressing that debate here.  But, I will argue that the iFi Micro iDSD BL provides a very affordable way for you to test each of these formats and that most of you will indeed hear noticeable differences.  Those differences, for the most part, don’t come from the resolution of the starting file as much as they come from how the iDSD Micro BL handles that file and how it applies digital filtering methods to produce the analog output.  My own view is the true benefits of higher resolution come from moving the filtering process further away from the audible (20Hz-20kHz) frequency band and thus less likely to produce artifacts that we can hear.  Specifically, I would argue that hi-res is not about hearing some frequencies not contained in a 16/44 file.  It is to benefit from gently sloping anti-aliasing filters, which, in turn, provide extremely good transient response. These filters also attenuate pre- and post-ringing.  What that means is that you can take an ordinary redbook CD file at PCM 16/44 or what a service like Tidal streams to your home and upconvert it in software to a much higher resolution file that is either PCM or DSD as you choose.  In addition, you can then carefully choose among a range of different software filters to apply before feeding that signal to your DAC. 

 

Most DACs do all of that internally when they are fed a 16/44 input.  How they do it is a decision the DAC manufacturer makes based upon what they “believe” is the best result using whatever their reference system is.

 

But your system is different.  Your ears are different.  Your listening space is different.  Given that, it is likely you’d have made a different decision if offered all of the choices your DAC designer went through.

 

That is where the iDSD Micro BL comes in.  It provides a highly affordable way to test those choices for yourself.  The tradeoff is you need to dedicate the time to learn how to use the software.  There is no “free lunch.”  What you save vis-à-vis a $5,000 DAC, you do have to spend some time learning and trialing with the Micro BL and your choice of software.

 

I have heard from a number of users that they have tried this or that software and can’t hear a difference.  That may be true because they don’t know what to listen for.  It may be true because their system isn’t resolving enough to matter.  But if I had to guess, in most cases it is because they didn’t take the time to learn the software enough to take advantage of its true capabilities.  To my ears, the differences are not at all subtle. 

 

The first step, in each case, is to test what level of upsampling your computer can perform before it starts to stutter.  In most cases a multi-core Intel i7 7000 series or better processor (or equivalent) together with at least 16GB of fast RAMM memory will be all you need for at least DSD256, if not DSD512 (depending in part on which filters you choose).  Next, make sure that your iDSD Micro BL is receiving that level of upsampling.  After that try both high res PCM and hi-res DSD and see which you prefer.   Most will say that DSD sounds a bit smoother.  The final step is then to test a variety of filters.

 

Every filter has its benefits and its tradeoffs.  What matters is which of those your own ears are most sensitive to.  Some ears are super-sensitive to linear frequency response or correctness of pitch.  Others are more sensitive to just how crisp the attack of a new note is and those ears generally dislike “ringing,” particularly “pre-ringing.”  Still other ears are sensitive to frequency roll-off over 10 kHz, whereas older ears often don’t hear much beyond 10kHz and are thus ok with tradeoffs that affect that region. What makes this step more difficult is that each software vendor has their own naming system for these filter choices (Audirvana using iZotope is all about numbers and there is a virtually unlimited number of choices), HQ Player offers filter choices with names like poly-sinc, minring, and closed-form but also offers a variety of Dithering choices and DSD Modulator choices, and Roon offers filter choices labelled “smooth” or “precise” and minimum or linear phase as well as DSD Modulator choices of 5^th and 7^th order CLANS and normal. 

 

This is where many of you ask: “Can’t I just tell you what my system I have and you tell me which choice is best for me?” If we all had the same rooms and ears, the answer might be yes.  Because we don’t, the only right answer is: “If you really want to get the most out of your system in your room, you need to try them all and the iDSD Micro BL gives you a really affordable way to do that.”

 

As you start listening to the different choices, if you are patient, you will hear clear differences, but you will also learn just how difficult it is to choose a single “best” result.

 

I’m going to use photographic rather than music terms to describe the effects of some of these choices because we have developed richer, crisper language to describe them in photography.  For example, some choices give the music more bloom, making it sound fuller in the same way that oversaturating the color in a photo can make it pop.  Choices that add more ringing can sound great at first because the ringing adds extra energy to the sound.  But over time your ears tire for the same reason that the best photographers don’t oversaturate their photos – too much all the time is just that, too much.

 

Other choices affect the seeming clarity or bite of the sounds.  Here the comparison is to using of sharpening tools in something like Photoshop.  Once again, a highly sharpened photo may look great at first glance; but it will grate on you over time because it isn’t really giving you fine detail; it is just highlighting the differences between light and dark.  Certain DAC/filtering choices will do the same, making the music sound really clear at fist listen, but grating over time.  A relatively new tool for photographers is “high dynamic range” or HDR.  It is a way to let a photograph show you a bigger spread between light and dark that the camera can really capture.  Certain filters can seem to do the same for music, highlighting certain differences that otherwise wouldn’t be noticeable.  When done right, it can provide significant benefit; overdone it looks and sounds, fake. 

 

Training your ears to hear these differences takes time and effort, but once you learn you can never go back.  You start noticing little things like just how certain notes hang in the air and decay differently from others.  Or you can suddenly hear a particular instrument stand out when in previous listenings it just blended in.  Or you can get a real sense of the room the music was recorded in, be it a studio, a jazz club, a cathedral or a stadium.  To me, the biggest difference when I get the filters dialed in right is that I suddenly notice how many more individual instruments I hear and how much more clearly I hear each one of them, including individual voices. 

 

So how does the iDSD Micro BL let you do all of this?  I’m going to explain it using the software combination I use most, namely Tidal + Roon + HQ Player (although I also have used each of Audirvana, Jriver Media Center, Roon alone and Amarra to do the same).  I use Tidal as a way to access 16/44 or better streaming content to go along with a library of digital files I have on my server that range from 16/44PCM to 24/376PCM, DXD, and from DSD64 to DSD512.  I use Roon to manage my music library and to present it to me in an extremely flexible and user-friendly fashion.  Lastly, I use HQ Player to handle the up-rezzing, conversion to DSD512 and filter choices because I believe that it has the most sophisticated set of filters available today.

 

The nice thing about doing all of this in software is that those choices are constantly improving through software updates in a way that hardware systems traditionally have not.  So, when your DAC manufacturer made his or her choices, they were based on the then available tools.  As newer, better tools are developed, many DAC manufacturers aren’t sending you updated firmware for their hardware (though some, like iFi do).

 

In my case, I let HQ Player upsample all of my files to DSD512 and then choose the filters I like best to feed the end result into my DAC.  Part of my reason for doing so is that I have highly resolving speakers (the Magnepan 20.1s) and I find that using PCM rather than DSD gives me just a bit too much edge on the sound.  Those with smoother sounding speakers may make just the opposite choice.  That is the easy part.  The choice of filters is somewhat harder as it also depends on what computer equipment you are using.  I use a dedicated PC built to handle the processing load that these software packages can create.  Older or less speedy computers may limit somewhat the choices you can make (for example you may have to choose DSD256 and different filters). 

 

The last step is to test filter choices (of which most of the software gives you many, and the explanations of what does what often leave a lot to be desired – partially because each choice will sound slightly different in your own system).  This is where the iDSD Micro BL really shines!  In my system the differences between filter choices are not subtle. Early on, there were choices that sounded great, but that no longer sounded so great after a few days of listening.  The longer I listened, the more I went for choices that seemed subtle on first listen, but ultimately gave my ears the most information about the recording venue/space, the exact location of musicians across the stage and the greatest ability to pick out individual instruments.  I have no doubt that my final choices reflect the interaction between my software, computer, the Micro BL, my amplifier and my speakers.  So, my choices are likely to be different than yours would be.

 

By taking your time with the iDSD Micro BL and making the choices that are best for your system, I believe that you can get as much sonic bliss from it as DACs costing 5-10 times as much.  Change your system, or switch from one room to another, and the iDSD Micro BL allows you to adjust your choices to best fit that particular system.  By itself, the iDSD Micro BL is an enormous value for a $500 DAC/headphone amp.  But combined with the right software and the choices that are best for your system, it can function on an entirely different level and teach you a lot about just how great your system can sound.  Yes, you also need to spend a bit of money on software and a fair amount of time in learning that software and making your choices, but the end result is hugely worth it. 

 

Stephan Dolezalek

[sdolezalek]

53 minutes ago, buonassi said:

Can you point me to a thread that discusses CPU requirements perhaps?  I'm new to the site and still figuring out the searching techniques.  Just for info, my chain is below:

 

There are two places that discuss CPU requirements: a) the Audirvana 3.1 thread as suggested above and b) a number of the HQ Player threads, including:

https://www.computeraudiophile.com/forums/topic/37965-roon-hqplayer-server-fanless-if-possible/?page=2&tab=comments#comment-759630

https://www.computeraudiophile.com/forums/topic/38043-ipad-pro-or-mac-airbook-for-server/?tab=comments#comment-759181

https://www.computeraudiophile.com/forums/topic/34601-ta-dac8-dsd-first-impression/?page=2&tab=comments#comment-758159

https://www.computeraudiophile.com/forums/topic/37775-best-cpu-for-hqplayer/?tab=comments#comment-749643

 

That should get you started.