iFi iDSD Micro DSD512 / PCM768 DAC and Headphone Amp. Impressions, Reviews and Comments.
Jul 26, 2014 at 11:58 AM Thread Starter Post #1 of 9,047


500+ Head-Fier
Mar 20, 2014
Knoxville, Tn
Hello all.  
I just took delivery of the iFi iDSD Micro Digital to Analog converter/ Headphone Amp.  
Over the next day or two I will be posting a complete review. (REVIEW NOW POSTED BELOW)  In the meantime I may be adding impressions as I go.  Early returns are impressive.  This is a serious audio tool.  It has an exhaustive feature set, and manages to sound excellent in the process.  
First impressions say it has the typical iFi house sound, but with notably improved clarity over the iDSD nano.  If you have been following the reviews of the Nano, you are aware of what a little overachiever it is.  Such an overachiever, that the iDSD micro needs to make a serious return on one's extra investment to make it worthwhile.  
I can say that yes, it is worth the extra investment.  The extra clarity and refinement are immediately obvious.  
iDSD nano and iDSD micro side by side

iDSD Micro on iRack with iUSB Power, Gemini USB Cable

Jul 26, 2014 at 12:00 PM Post #2 of 9,047
It was around February of 2014 when I first read of iFi while skimming the Head-fi forums. I was looking for a DSD capable DAC in the sub $500 range to replace the first generation Audioquest Dragonfly serving my desktop listening needs. There was only a handful of options at the time, and my interest in DSP free DSD playback further limited the choice. Actually, my choice was made for me. The iFi iDSD nano was the only DAC I could find that fulfilled this requirement in my price bracket. The only problem was I knew nothing about iFi, and I was concerned by the incredibly low price. Surely the raw sound quality would be compromised at this price point. Then again, at a mere $189 there was little risk, so with a 'What the heck?' attitude I ordered one. And wow. Wow. Wow again.
I am glad I took the risk of a blind buy. In addition to being impressed with the sound quality, I became equally impressed with the crew at iFi/ AMR. Their customer interaction and support is superb. And they are truly committed to their vision of Hi-Fi, which is unapologetically different than the hi-fi norm. In the end, they are committed to providing the best sound and most useful feature set for the dollar.
It should come as no surprise, then, that I followed closely the crowd design of the iDSD Micro, and am among the first 512 owners. An 'Octa-Adopter.'
'Octa' as in 8x DSD, or DSD512. Yes, this DAC will playback DSD rates up to 24.6 Mhz! This is the first example of such support in a consumer level product. It also supports PCM up to 768khz. Although I know of no content currently available at these high rates, upsampling to DSD512 is possible in software, and PCM 768 allows for DSD256 playback via DoP, which means ASIO is not required for playback at that rate. Although I am not as familiar with the state of Mac computer audio, I believe this may be the first time DSD256 is available on the Mac without a need for special driver software.
I mentioned earlier that iFi doesn't follow the hi-fi norm. What does that mean? iFi believes in minimal DSP, and believes that one should be listening to as close to the source audio as possible. DSP's such as upsampling, volume control, format conversion, etc. create unavoidable mathematical losses. The more conversions, the greater the losses. The more changes to the source signal, the more likely the changes become audible. This may especially be the case with DSD. DSP such as filtering, sample rate conversion and volume control require conversion of the 1-bit bitstream to a multibit intermediary, and remodulation back to 1 bit.
Therefore, the iDSD Micro uses a chipset that converts DSD to analog natively with no extra digital conversion or DSP. The 1 bit DSD signal is sent to an analog FIR filter for conversion. That's it! Also, the iDSD micro has a 'BitPerfect' filter option for PCM. This eliminates the oversampling reconstruction filter used in PCM conversion.
So in a DAC loaded with features, simplicity characterizes the nature of the actual audio conversion. This matches my personal audio values.
Unboxing an iFi product is a treat! Packaging is reminiscent of that other "i" company.
In the box you will find a plethora (hyperbole, of course) of quality adapters and cables. Which calls attention to the unique 'OTG' USB port on the back of the Micro. It is a unique port engineered for mobile convenience. To use it with a standard desktop USB cable, an adapter is required. Two versions of the adapter are included. The adapter I chose to use is cable-less. The other adapter has a very short cable between terminations. I chose the first adapter presuming higher quality, but the cabled version may be more convenient when space behind the DAC is a concern. The 'hard' adapter combined with my iFi Gemini cable requires several inches of clearance.  It is also an interesting little detail that the 'hard' adapter comes packed in an anti-static bag, like what you would expect to find enclosing delicate computer components.  Also, I think it is important to add that the included USB cables are OTG cables, so if you don't already have an expensive USB cable like the Gemini, I would suggest forgetting about the adapters and going with one of the included cables.
This is all I will have to say about the adapters, mobile uses, battery, etc. I will leave that to others, as I use this iDSD exclusively in a desktop environment, and cannot adequately review mobile functionality.
Build quality and appearance is typical iFi. The iDSD micro is well built but take care with the switches. They feel a little fragile, and as a matter of fact, I had some trouble with a sticky switch.  My over aggressive tugging, attempting to 'un-stick' it, caused the red 'Turbo' switch that controls amp output level to go flying off into the floor!! Fortunately it easily reattached, and works properly now.
Now on to the good stuff! The sound! Crisp detailed highs, smooth upper mids, slightly warm lower mids and upper bass. Clean extension into the lows. Not too much bass; just about right. Does it deviate from neutral? That is something I am not sure I can answer. Tonal balance is the product of an entire system, and all I can tell you is how it sounds in mine, which is a custom built AMD PC running the latest Jriver Media Center software, iDSD micro, iFi iUSB power, iFi Gemini 'split' USB cable, and a modded USB cable eliminating the 5v line pre iUSB Power. The review headphones are Grado RS1i's.
In comparison to the iDSD nano, the sound is the same tonally, but there is a notable increase in detail and dimensionality. On the Nano, audio images are wide, but slightly flat in comparison. The Micro has greater depth of soundstage. Never is the extra detail harsh, though. The micro is always delightfully smooth and listenable.
DSD was the strong suit of the iDSD nano, and is improved in the Micro. I feel the greatest improvement, though, is with PCM material, especially using the BitPerfect filter. The promise of the Burr Brown DSD1793 segment DAC is realized more fully here. PCM sounds both silky smooth AND extremely detailed, like a hybrid of true PCM and Delta Sigma conversion, which is EXACTLY what the segment DAC is.
For headphone use, which is how I exclusively use the iDSD, power is abundant and flexible. There are three settings, from Eco mode to 'Turbo' mode, which will tear paint off the walls with my Grados!!! Eco mode is already stronger than the headphone amp in the iDSD Nano, but I have settled on the middle 'Standard' mode for all my listening.
The headroom it provides for the dynamic orchestral recordings that dominate my listening is welcome. This addresses the only other weakness of the iDSD Nano. The iDSD Micro has plenty of power, dynamic swing and driver control to keep up when the music gets loud and complex.
I enjoy the 3D and XBass 'Analog Signal Processing'. The effect of both is subtle but notable. They never get in the way, and depending on soundtrack can really enhance the experience. For instance, the bass drum on orchestra recordings has deep authority with XBass turned on, and 3D mode really does widen the soundstage nicely, and puts the center image more 'out in front.' But I did notice that with 3D mode engaged, images on recordings I know well were placed too far to the edges for my liking, and overall imaging suffered. Instruments gain a greater sense of space, but lose their precise placement 'in space', so I do the majority of my listening with 3D mode disengaged.  XBass seems ESPECIALLY useful at lower to moderate listening levels, filling in the low end nicely.  At higher levels, or with music recorded with little dynamic range, the bass emphasis may be a bit much.  But as most of my listening is to very dynamic music with moderate average levels, I leave XBass engaged most of the time and do enjoy the effect.  Ultimately, results vary from soundtrack to soundtrack, though.
There are many more features included in this incredible product that I have not mentioned, but I believe I have covered everything that stands out to me after two days of listening. This is a special product, both in feature set and sound quality. Designed by a renowned audio engineer, with customized software and extreme functionality. Oh, and it sounds in a word, amazing. If you are looking to spend in the $500 to $1000 range, and maybe even more, you owe it to yourself to hear the iDSD micro.
Highly recommended.  
Jul 26, 2014 at 3:05 PM Post #3 of 9,047
Have you tried it with both USB 3.0 and 2.0 ports?  
Jul 26, 2014 at 4:44 PM Post #4 of 9,047
  Have you tried it with both USB 3.0 and 2.0 ports?  

unfortunately I only have USB 2.0 ports.  I do believe iFi modded their code in the latest firmware to address Intel USB 3.0 issues.  But again, I cannot directly confirm one way or another that 3.0 is trouble free.  
Jul 27, 2014 at 9:25 AM Post #5 of 9,047
  Have you tried it with both USB 3.0 and 2.0 ports?  

Yes, full compatibility with any USB3.0 port or USB2.0 port.
The nano iDSD had the USB 3.0 port firmware update (including Quad-Speed DSD256) back in May.
If you are a NANO iDSD owner, please go here for the update:
Do NOT UPDATE if have the micro iDSD.
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Jul 27, 2014 at 12:27 PM Post #6 of 9,047
Yes, full compatibility with any USB3.0 port or USB2.0 port.
The nano iDSD had the USB 3.0 port firmware update (including Quad-Speed DSD256) back in May.
If you are a NANO iDSD owner, please go here for the update:
Do NOT UPDATE if have the micro iDSD.

Thank you very much!  I was still running the Beta 6.52 firmware and while it allowed me to use the Nano on my Macbook, when I moved it to my PC, I had to use one of my USB 3.0 ports because the beta software didn't work with my USB 2 ports.
I downloaded the new firmware and installed it without problems and now I can switch back and forth between USB 2 and 3.0.  Awesome!
Jul 28, 2014 at 3:29 PM Post #8 of 9,047
A question about using the iDSD Micro with amplifiers and speakers:

Hey folks, got my unit Saturday, unpacked her yesterday but still haven't had time to sit down and put her through her paces. That won't be until tomorrow evening at the earliest.:mad:

Looking for advice on what settings to use when feeding either a 100 Wpc solid state power amp (Audio Research 100.2) or a 45 Wpc integrated tube amp (Conrad Johnson CAV-50).

Will be listening mostly to PCM and Internet Radio for the time being. (I can't wait to hear the iPurifier's effect on that sometimes very nasty internet noise.)

Thanks in advance for your help!

Jul 28, 2014 at 3:41 PM Post #9 of 9,047
When I got my micro I first put put the power from eco to normal.  Second, I put the output switch from direct to preamp mode that that I can use the micro volume control to control my active monitors. Also the preamp mode is currently the only way I can control volume on native DSD files.
Jul 28, 2014 at 4:22 PM Post #11 of 9,047
I would say it is even smoother and clearer than the nano. Sill has plenty of detail. Very little dynamic range compression at all. You can check my posts by clicking on my username. I would recommend to charge the micro at least a full day regardless of the charging light at first time. It seems to setting in better and the battery seems to run cooler after that.

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