iFi micro iDSD Signature Review

The iFi micro iDSD Signature is the latest in iFi’s line of highly adaptable portable DAC/amp combos. The Signature follows up from the Black Label and provides some tweaks to the design as well as upgrades to the digital and analog sections of the device. With the latest round of improvements, does the iDSD Signature take iFi’s signature sound to the next level?

The Build and Design

Like the Black Label, the iDSD Signature is on the “transportable” end of “portable.” It's battery powered with solid battery life, and can very easily fit in a bag, but its length and weight are going to keep it out of your pockets. The device itself is a simple, sturdy design. It has a long, thin aluminum shell, with the 6.3mm unbalanced and 4.4mm balanced headphone outputs, volume, XBass+, and 3D+ on the front – and the USB and SPDIF input, as well as the RCA output on the back. The left side features three way switches for Power Mode (Eco, Normal, and Turbo), Filter (Standard, Minimum Phase, and Bit Perfect), and IEMatch (Off, High Sensitivity, Ultra Sensitivity). It’s all very sleek and neatly arranged, but one quibble I had is that I was completely unable to turn XBass+ or 3D+ on or off without accidentally changing the volume.

iFi micro iDSD Signature Unboxing

The package includes everything you need to get started: a USB data cable, USB charge cable (like many portable Hi-Fi devices, charging and data are separated to eliminate noise), a 6.3mm to 3.5mm adapter, RCA cables, the SPDIF/Optical adapter, USB-A to USB-B adapter, and a set of elastic bands designed to help you temporarily attach a player or phone to the iDSD Signature for increased portability. As always, iFi delivers with an excellent accessory package.

The Sound

The iDSD Signature is slightly warm, but on the neutral end of iFi’s house sound. The sound stage is quite good, and it provides excellent dynamics and response. In terms of overall sonic performance, it provides an improvement in detail, resolution, and soundstage over the micro iDSD Black Label.

As I mentioned in the design section, the iDSD Signature includes the ever popular suite of iFi features including XBass+ and 3D+, as well as a built in IEMatch, selectable power output, and filters. XBass+ is excellent as ever, adding just the right touch of low end to more flat/neutral headphones like the HIFIMAN Ananda without feeling overpowering or compromising the delivery of the mids and highs. 3D+ has more mixed results, sometimes providing a slightly better sense of space, but other times it doesn’t seem to make much of a difference.

The “Eco, Normal, Turbo” selection really just seems to be “Low, Medium, High” gain selection. In my testing, the modes worked essentially as expected: Turbo provided the best response and most headroom for planar magnetic headphones like the HIFIMAN Ananda and Meze Empyrean, Normal was good for dynamic headphones and most IEMs, and Eco – in addition to improving battery life – was perfect for more sensitive IEMs.

iFi micro iDSD Signature Meze Empyrean

IEMatch provides an alternate way to tame noise from sensitive IEMs, and depending on the specific IEM and your own preferences, you may want to use Normal mode and IEMatch instead of Eco mode. With the Campfire Andromeda and Empire Ears Hero, Normal mode with IEMatch provided a better soundstage than Eco mode. However, IEMatch also made the volume a little bit finicky, and there was a pretty steep jump around the 25% mark where you go from low volume to no volume with IEMatch on. Again, this is the sort of thing that you’ll want to sort out for yourself and your specific headphones, but the key point here is that the iDSD Signature gives you the tools you need to tweak the sound to match the different headphones or IEMs you’re using.

Digital Filter selection isn’t quite as exciting, but provides some subtle tweaks to the sound. Bit Perfect seemed to be the most neutral to me, while Standard was a touch warmer, and Minimum Phase was virtually indistinguishable from Standard to my ears. According to the official documentation, Standard provides iFi’s preferred measurements, Minimum Phase reduces pre and post ringing in the digital signal to create a more natural sound, and Bit Perfect provides the most accurate reproduction of the original signal.

In terms of power, the Signature iDSD totally delivers. With a max of 10V and 4100 mW in “Turbo” mode, it provides enough juice for demanding over ear headphones, and powered everything we had available in the office with plenty of volume without getting past 12 o’clock on the dial. You do need to balance out power and battery needs though, as using the high power modes limits the battery to just about 6 hours. In my use around the office, I found that 8 hours of continuous use on Normal mode was typical. iFi claims that you can get up to 12 hours with Eco mode. The balanced 4.4mm channel provides the extra power to improve the impact and provide additional headroom for more demanding headphones. The power improvements were definitely noticeable, but otherwise the balanced channel performed the same as the unbalanced.

Comparison: iFi NEO iDSD

If you’re in the market for a DAC/Amp right now, the big question on your mind is probably going to be whether you want the iFi NEO iDSD or the micro iDSD Signature. To compare these two, we’ll talk about the sound signature, convenience, and usability. You can also see our full review of the NEO iDSD.

In terms of sound signature, the NEO iDSD captures the balance between iFi’s warm, musical house sound and strong technical performance right out of the box. The iDSD Signature provides a slightly more neutral tuning, with a little more air in the highs, but also with a number of options to either push it a little bit further towards a neutral sound, or to give it a little bit more of the warmth of the NEO iDSD. The soundstage and imaging is very close, but I felt that the NEO iDSD more strongly enhanced the feeling of space and the imaging quality on some headphones that don’t have particularly large soundstages to begin with like the Meze 99 Classics and iBasso SR2.

iFi micro iDSD Signature vs iFi NEO iDSD

In terms of convenience, the winner will probably depend on what’s more convenient to you. Is convenience being able to connect to a desktop device with your phone via Bluetooth or is convenience being able to throw it in your backpack and take it with you? If you’re looking for a desktop unit, and Bluetooth connectivity is important, then the choice should be pretty clear for the NEO. If portability is at all a concern… well then you’re probably going to need the one with the internal battery. At the same time, while the NEO may be able to power 80% of headphones sufficiently, the iDSD Signature’s additional power output can probably handle 95%, and the built in IEMatch makes it a stronger choice for IEMs.

For general usability, the NEO is the clear winner. The iDSD Signature is more geared for the hardcore audiophile who wants as much control as possible over every aspect of the sound, and while switches are nice (I love turning knobs and flipping switches), it’s often difficult to adjust the front switches without accidentally changing the volume, and the side switches aren’t clearly labeled, so until you memorize what each doesn, you need to flip the device over to check the settings. By contrast, the NEO iDSD has a volume knob and an input selection, as if to say, “This is the sound. You love this sound. Just plug in your headphones and enjoy it.”

The Bottom Line

The iFi micro iDSD Signature packs a lot into a little box. It is versatile and powerful with a natural, musical sound signature. If you’re looking for a portable device that can do it all – and sound great doing it – the iDSD Signature might be just what you need.