September 2014
 

iFi audio Micro iDSD Battery Powered DAC / Headphone Amplifier
Holy &%$&! the Micro iDSD DAC with headphone amp rocks!
Review By Steven R. Rochlin

  Welcome to 2014 where online crowd-designed products have firmly made their way into high-end audio. Have been keeping a very close eye on the development of the ifi Audio Micro iDSD as reviewed here. Within only the past few years, manufacturers have wisely opted to go to popular discussion boards, such as Head-Fi, and ask board members what they'd love to own if they created a high fidelity audio product. This is a change from years past where manufacturers would develop and design 100% in-house and then release a product in hopes of it being well-received. iFi Audio's Micro iDSD ($499) takes the road many more will pursue in the years to come. Today, you mix in brilliantly adaptive designers with social media and you have the potential for explosive sales. What is that old adage? Oh yeah, give the customer what they want. Business Insider's December 18^th, 2013, SAP-sponsored article says "Because now more than ever, with access to infinitely more purchasing options, customers have the power to decide how, when, and whether they will do business with a particular company. In the future, the companies that will thrive are those able to give customers exactly what they want, the way they want it, when they want it—before they even know what they want." Ok, perhaps that last part is Steve Jobs territory, yet the other points are common business sense in today's marketplace. You need to be actively engaging customers. Today it is my joy to bring forward one of those great designs that meets exceeds, their customer's 'wants list'.

Technical Details
ifi Audio's Micro iDSD is the only DAC in the world, says the company, to play true native octa-DSD512, PCM768 and double DXD. It can drive virtually any headphone with a tremendous 10v/4000mW output. There are three different power modes Eco, Normal and Turbo (250 mW, 1000mW and 4000mW respectively). Thus anything from highly efficient IEMs to my beloved Audeze LCD-3 Steampunk edition can be driven with ease. A SmartPower function handles charging the internal 4800mAH battery. This battery storage is so large that it can fully recharge an iPhone twice over! The ifi Audio Micro iDSD is compatible with Apple and Android devices.

Other features include 3D Holographic and XBass, which expands the soundscape within your head and extends bass output accordingly. This is not just for headphones either, as the XBass and 3D Holographic have specialized, custom programming/filtering for both headphones and loudspeakers. There is Direct/Pre-Amp functions, a 3.5mm input, S/PDIF input/output and far more in this incredibly versatile product. You can see their website for a complete list of features.

As for the extremely critical internal power supply, designer Thorsten Loesch went through the same troubles as others during initial design of the iFi audio Micro iDSD. "Okay, fun week. After flying back from Shanghai I found the first cut circuit boards for the iDSD micro have come back, so I have to test them. Keeping Gaggia in business with an Espresso or ten strong enough to stand a spoon in and just jump right in. All went well until we came to the amazing new power supply for the DAC and analogue. Clearly a 4.2V battery is not going to cut it where you need +/-8V, so we designed something really cutting-edge into the iDSD micro. It even works. The only problem is that efficiency is way too low, everything gets too hot and the special step-up converter IC gets way hot and shuts down as soon as a bit of current is drawn. Trying different parts etc. got nowhere, there seems something that just does not work in this particular case. Adding an improvised heat-sink to the IC allowed to complete testing, but still that one is definitely FUBAR. Excluding the power-supply that cannot deliver enough current for the Headphone Amp to drive any load, it all tests really well. So we can make the few small corrections and get the next bunch of PCB's made up, except for the power management. With only 30% of the current taken in from the battery coming out at the other end of the converter, with the rest turned into heat there is no way we can use this in production, battery life would be a joke and the whole thing would run hotter than a Class A Amp." After a variety of redesigns, they finally found a solution that works extremely well, while also providing hours upon hours of musical bliss from the internal battery power supply.

Listening
Right of the box the unit sounds quite good, yet you really need at least 200 hours for things to settle in nicely. After another 100 hours of use, the ifi Audio Micro iDSD is ready to deliver everything she was designed for at top-notch sound quality. This is why no one should ever try to reviewer a product after only a week or two of use, as the component itself has not reached its full potential! Of course wise readers and longstanding audiophiles know it takes time for a product to achieve its best sound potential.

After about 100 hours there was still some slight dynamic compression. After 200 hours of use the compression was reduced to a good degree, yet at the 300 hour mark there was an extremely small bit of dynamic compression as compared to the very best I have heard at any price (read: cost-no-object $25,000 setups). For a unit that does so many wonderful things for a mere $499, this is an outstanding achievement!

The lower mids are a slight touch warm sounding, yet are minor and if anything add a very inviting sound. Almost a teeny tiny touch tube-like... almost. For those of you who are curious, during break-in the uppermost frequencies were a touch on the shallow side yet opened up quite nicely. What I mean by that is, it seemed that while the instrument's sound was there, it was lacking a bit of weight and solidity. Most reviewers use 'heft and weight' for lower registers, yet it is a factor at all frequencies if one pays close enough attention and one's high fidelity audio gear is capable of seamlessly and transparently delivering all frequencies in perfect time and phase. This reminds me, for filtering I chose the Minimum Phase setting as it sounded best to my ears within my systems.

Audeze LCD-3 Headphones With Nordost's Heimdall 2 Cable
For headphone duties I could not have picked a better, or as challenging to drive, Audeze LCD-3 custom factory-made Steampunk Edition planar magnetic headphones. While the stock cables are good, I substituted them for the far superior Nordost's Heimdall 2. These extraordinary cables are made with 32 AWG 7/40 conductors that are individually insulated and twisted using Litz construction. Nordost's Heimdall 2 headphone cables provided a great improvement to overall sound quality to the spectacular Audeze LCD-3. Since some of us can be a bit rough with our headphone cables, Nordost wisely included an Aramid fiber strength member to the cable's construction. Furthermore, Nordost's proprietary Micro Mono-Filament technology with extruded FEP insulation around the conductors furthers the sound quality and overall durability of the cable. Thanks goodness Nordost includes a variety of end connectors and adapters, as the high-end headphone industry uses a few different types of contact plugs. Everything from top-to-bottom frequency response to inner detail and resolution were improved with the Nordost's Heimdall 2 over the stock Audeze cables. If you have a set of Audeze headphones and want to get the best from them, then you had better get yourself a set of Nordost's Heimdall 2 headphone cables ASAP.

Back To The iDSD
Getting back to the ifi Audio Micro iDSD, I almost want to say the internal amplification sound like a seriously good tube amp, but that would be generalizing. As you know, all generalizations are wrong. Still, the sound does have a smoothness and characteristic like that of a triode tube amplifier to some degree. I'd say more like a 300B than a 845 or my fave 211, yet closer to the hints of a 211 than the 845. Well, since all generalizations are wrong I may as well take the complete liberty to make absolutely no sense on a purely logical manner. Those of you who know what I mean about tubes, you know who you are and be proud of that fact, probably comprehend the concept of what I'm trying to convey here.

Top to bottom frequency response and harmonics were spot on and very transparent. i heard a seamless, cohesive flow of the frequencies with very smooth overall response. Imaging was outstanding, and with the 3D Holographic enabled I heard a seamless expansion to the soundscape. With properly engineered recordings, it is as though one could bask in the enveloping soundscape as it is smoothly portrayed and delivered to your ears with headphones. With loudspeakers, it also gets quite interesting and is as equally smooth at rendering an enhanced, very wide stage as compared with the same music without using the 3D Holographic setting.

Perhaps in great part due to extensive research and development within the power supply and amplification stage, the iFi Audio Micro iDSD delivers impressing, nearly reference-level bass. This is astonishing for any unit, let alone one that costs a mere $499. While many portable headphone DAC/amp products only produce 1200mW, the iDSD's amplifier can produce upwards of 4000mW and can directly drive highly efficient home loudspeakers! Thus, as many (?most?) such units have long run out of amplification, the iDSD have over twice as much amplification and thus far more headroom so as to not dynamically compress the music. This is especially true with EDM, techno and bass-heavy hard rock. If you love pipe organ music as much as I do, those 32' pipes come though very clean and with proper oomph. If you're a basshead and want more, simply turn on the XBass setting and get ready for the vibratory capabilities of frequencies below 50 Hz. Whilst I could go on and on about setting and specific music genres, the bottom line is that no matter what I played through the iFi Audio Micro iDSD, it was delivered with an amazing clarity, resolution, soundscape and authority that would easily challenge, and probably trounce, any portable DAC near its price of only $499.

A Little Secret
As a stand-alone DAC, only some crazy reviewer-type would compare the $499 iFi Audio Micro iDSD to the ~$26,600 Gryphon Audio Designs Kalliope DAC. Allow me to let you in on a little secret. When designing the Max Rochlin Memorial S/PDIF cable over a decade ago, i knew that those early DACs had problems. Add to that fact that those going the DIY route would probably use said cable on less-than-reference-level DACs back in the day. Thus i designed it to have the characteristic of being smooth-sounding and musically enjoyable versus trying to deliver the very last word in all those audiophile-type aspects. To this day, 10 years later, i still get e-mail praising the sound quality, which the Max Rochlin Memorial Cable delivers in spades even with modern gear today. If you want true reference-level sound quality you're going to pay for it. If you want something at a lower price point, then you hope the designer made the right compromises you can live with whilst also delivering an involving and engaging sound that brings hour after hour of musical bliss. iFi Audio, imho, made all the right compromises and could listen to the Micro iDSD hour upon hour and get lost within the music. It is obviously not producing the very last word in bass definition, transparency and high frequency extension. iFi Audio's Micro iDSD does produce music that in involving and very enjoyable. If you want reference-quality sound that rivals the very best recording studio, then you need to have the Gryphon Audio Designs Kalliope DAC. For those on a budget plus want a headphone amplifier and battery powered portability should seek out the iFi Audio Micro iDSD unit. 

The Wise Music Lover
About two years ago during a seminar at RMAF 2012 I warned other reviewers, and the audience, about the 'DAC-of-the-month' club pitfalls we were (then) about to experience and it was sad to read how many people fell into that well-worn trap as they did back in the 1990's during the first round of high-end DACs for home audio. This is also why smart reviewers wait it out instead of saying this or that device is the best, only to have said device upgraded less than a year later (and/or new firmware) and the game begins all over again... and again... and yet again within the past two year period since the RMAF seminar. Longstanding music lovers who peruse reviews can get burned out from the endless accolades, countless magazine awards, and perhaps constant equipment upgrades trying to keep up with the Joneses. This can also turn off a magazine's readership who see over-the-top reviews one after the other, month in and month out and thus make our love of achieving the very best for the dollar within their music system so very frustrating... let alone all the time and money thrown about without care of true longstanding value and enjoyment. This is also why reviews by Yours Truly take time and I am never one to just jump aboard without very careful assessment of technology and the marketplace. In addition, knowledge of newer technology already available, and those being developed within the industry, pays dividends. Products that use old technology have merits, provided newly implemented techniques are done correctly. It makes me wonder how much time people have wasted trying bi-monthly upgrades and yet never really reaching a truly enjoyable system on a longstanding basis. It also makes me wonder if said people value their time, as of all the things we have within this world, one's time is the most valuable resource. If you're on a budget and want to hear what all the commotion is about computer audio and/or headphone amplification, then the iFi Audio Micro iDSD should serve you well on a longstanding basis. It should deliver hour upon hour of engaging and enjoyable music that is never fatiguing or offensive given the proper music (read: some music is recorded horribly, or on the other hand said music is meant to sound 'offensive', as the artists intended it that way).

Award-Winning Design
As this month is Enjoy the Music.com's annual Blue Note Awards, am sure you can already tell that the iFi Audio Micro iDSD has earned not just my highest of respect, but my personal fave award for best portable DAC/amp combo too! For only $499 the ifi Audio Micro iDSD delivers and incredible value, can handle every conceivable digital music file type today and for the foreseeable future for many years to come. You also get a variety of settings for filtering, XBass, 3D Holography, variable amplification output setting, plenty of amplifier power and it can even charge your USB-powered device too! It can also serve as a headphone amplifier and as an external DAC for your high fidelity audio system. The bottom line here is that it will be very hard for any such unit in the years to come to sound better while also providing so many features at this price. In this word of disposable and cheaply made audio devices, I foresee the iFi Audio Micro iDSD unit being one of those products you will be gladly using 10 years from now. A decade from today it should still handle everything you can throw out it from modern digital music files, an external DAC, plus handle everything from custom IEMs and those hard-to-drive planar magnetic headphones too. Smart audiophiles can stop wasting their hard earned cash with typical DAC-of-the-month products and instead get a device that can keep them happily enjoying the music today and for many years to come. As always, in the end what really matters is that you...

Enjoy the Music,

Steven R. Rochlin

Specifications
Type: Battery powered DAC with headphone amplifier

Inputs
USB 2.0 Type-A OTG socket (with iPurifier technology built-in)
Compatible with computers (Apple/Win/Linux), iPhone, iPod Touch, iPad and Android Devices, camera kit or USB-OTG cable required (full USB 3.0 port compatible)

Intelligent S/PDIF coaxial RCA three-way combo S/PDIF port
Coaxial In/Out and TosLink optical In) for up to 24-bit/192kHz PCM 

Outputs
Analog audio RCA, SmartPower Socket fast charge all portable devices. Compliant with USB battery charging standard 1.2V to 5V @ 1.5A

Controls 
  HP Output: Audio 6.3mm Headphone Jack 
  Volume with Power On/Off switch
  Precision analogue volume control <2dB tracking error 
  3.5mm Input Auto disable the digital section when this is in use 
  X-Bass On/Off 
  3D Holographic Sound On/Off auto-switching
  3D Holographic speakers and headphones (two separate and distinct circuits) 
  Power Mode: Turbo, Normal, Eco computer controlled power and gain scaling 
  Polarity: Normal or inverted 
  Filters: 3 positions, 6 filters total
  Line Direct / Preamplifier function enable / disable, 0/9dB gain selectable
  Fixed 2V or variable to 5V 
  iEMatch: Perfect-matching circuit for IEMs

DAC Section
  DAC: Dual-core DSD, DXD, PCM DAC by Burr Brown two-DAC chipset
  Chip has 4-Channel; 8-Signals, custom interleaving for maximum SNR
  Bit-Perfect DSD processing, Bit-Perfect PCM processing

Clock
  Ultra low jitter GMT computer controlled
  Femto Clock: RMS jitter 12 kHz to 1 MHz < 280 Femtoseconds

Audio Formats (all native decoding, no internal hardware conversion)
  DSD 512 / 256 / 128 / 64, 24.6 / 22.6 / 12.4 / 11.2/6.2 / 5.6 / 3.1 / 2.8 
  DXD 2x / 1x at 768 / 705.6 / 384 / 352.8 kHz
  PCM 768 / 705.6 / 384 / 352.8 / 192 / 176.4 / 96 / 88.2 / 48 / 44.1 kHz

Filters 
  PCM Bit-Perfect Processing/Minimum Phase/Standard Digital filters selectable 
  DSD Extreme/Extended/Standard Range Analogue filters selectable 
  DXD Bit-Perfect Processing Fixed analogue filter

DAC Section Specifications
  Dynamic Range (Line) >117dB (A-weighted) 
  THD & N (0dBFS Line) <0.003% 
  Output Voltage (Line) >2V 
  Output Impedance (Zout) < 240 Ohm 
  Jitter (correlated) Below AP2 test set limit

Headphone Power Output
  Turbo mode 10.0V/4,000 mW @ 16 Ohm (>1560 mW @ 64 Ohm)
  Normal mode 5.5V/1,900 mW @ 16 Ohm (>950 mW @ 32 Ohm)
  Eco mode 2.0V/500 mW @ 8 Ohm (>250 mW @ 16 Ohm)

Specifications For Headphone Amplifier Section
  Dynamic Range (HP) >115dB (Eco Mode, 2V Out) 
  THD &N (HP 500mW/16R) < 0.008% 
  Output Voltage (HP) >10V (Turbo Mode) 
  Output Impedance (Zout) <1 Ohm (iEMatch not engaged) 
  Maximum Output Power 4,000mW @ 16 Ohm Load
  Continuous Output Power 1,560mW @ 64 Ohm Load

Price: $499

Company Information
ifi Audio 
E-mail: contact@ifi-audio.com
Website: www.iFi-Audio.com