iFi audio iDSD Signature

I really liked the little hip dac from iFi but I still ran into power issues on more demanding full size headphones. The iDSD Signature fills that need by offering a middle of the pack(in physical size) unit that still allows you to take it in a bag with you out and about yet it still manages to give a good amount of power output as well. Alright, let's get into the review of the Signature!


Thanks to iFi and @Sebastien Chiu for hooking me up with a review unit. While I always appreciate stuff being sent in to test and review, It never affects the rating of my review.

Gear used​

S.M.S.L. SU-9/SH-9, iFi iDSD Neo, THIEAUDIO Clairvoyance, DUNU EST 112, DCA Aeon Noire, Focal Radiance.

Looks and Feel​

I absolutely love the looks of the Signature. It’s a nice long brick that comes in a really nice dark metallic-ish blue color and feels wonderful and well built. The device isn’t too hefty and while you can technically take it out for portable use, It would be harder to fit in a normal pocket with an attached source device. All the space was well utilized as well inside of the casing. One side of the device has switches. The front has the jacks, volume knob and switches all close together and the back has enough room to fit the USB in, RCA out and 3.5 optical in.

Accessories and unboxing​

Inside the box we get an abundance of accessories. iFi includes a set or RCA cables, USB cable, USB-B to A adapter, short USB-C charging cable, optical to 3.5 and rubber rings and a pad to keep things from scratching. I always feel like iFi includes a good chunk of accessories with their gear.

Switches and volume knob​

On the unit's right side we get a power mode switch which acts as low, medium and high gain. The next switch is a filter switch which goes standard filter, minimum phase filter and bit perfect filter. I can only assume the bit perfect filter is a linear phase. I can never really tell the difference between all of these filters on any DAC honestly. The final switch is for the famous IEMatch that helps with super sensitive headphones. Unfortunately I don’t have my set of andromeda anymore for hiss/floor noise testing but the DUNU ZEN picks up hiss via balanced fairly easily so that’s what I used to test the IEMatch. While I can’t confirm it, I could swear the off position provided the best sound. I also didn’t get that much annoying noise out of the 4.4mm jack compared to other gear so it will be personal preference on how quiet the floor noise needs to be. This wasn’t a problem on the ECO mode which was as high as I was willing to go on sensitive IEMs in terms of available power.

Sound(overall)​

These final impressions were done off the iDSD Signature with no external amp usage. This will be what the micro iDSD Signature sounded like with all the headphones I used. Things like headphone pairings or using different external amps will produce different results and impressions vs what my ears hear on my specific gear.


The Signature has a fairly musical sound to everything I plugged in. This is one of the better DAC/amp combos for chilling out and simply listening to music. The lows come in with a slight boost to the sound which makes all the headphones I tried have a little extra thump down low. Mids come in clear with a little warmth that helps with some of the more intense sounding vocals. Same thing with the treble. While it’s fairly clear and resolving, It has a nice warmth that can take the slightest edge off sibilant sounds. The Signature overall sounds like a nice warm amp but it still sounds fantastic and at its price point I have zero complaints about the sound.

Imaging/Soundstage​

The staging has decent width and depth. Not quite as good as some larger desktop gear I’ve tried but I think for a transport device like this, it’s fine. I’ll take a balanced width and depth any day over something that sounds way too wide or way too deep. Imaging is always something that’s headphone dependent IMO but I had no issues with the headphones I tried.

Inputs and outputs​

We get a USB(male) input, 3.5mm optical in and a set of RCA outputs. I think the option for the RCA outputs is a nice touch for a “portable/transport” device like this. I would still like to see Bluetooth in something this expensive since devices like the FiiO Q5 which comes in cheaper and has Bluetooth(at the cost of power output”. I would also prefer a USB-C input instead of their weird full size usb male input. They stay consistent and use it on everything so I’ll at least give them that.

Personal grips with the Signature​

The only issues I have with the Signature are small nitpicking issues. I wish the ECO mode had less power so if I accidentally adjust the volume, I don’t die or kill a set of IEMs. I also wish iFi would use stiffer volume knobs. This is an issue I had with the hip dac. I don’t take the Signature outside in a pocket so it gets a pass in this instance. The volume knob channel imbalance is noticeable from 9(close to off) to 11-ish o’clock. I didn’t have anything super easy to power that produced any imbalance issues but this could possibly be an issue as one set of IEMs was at my preferred volume between 11-12 o’clock.

Single ended/balanced power outputs​

Since the unit isn’t truly balanced, we get the same power output via the 3.5mm and 4.4mm jacks. The power output is fairly impressive and we get a max output in eco mode of 500mW, 1.9 watts in normal mode and finally 4.1 watts in turbo mode. iFi has a terrible habit of not using mW into 32ohm numbers and I didn’t feel like trying to do the calculations personally. What I will say is that eco mode is usually too much for sensitive iems(use IEMatch to solve this), normal mode is good for pretty much everything and turbo mode is only for extreme uses.

IEM pairing opinions​

DUNU EST 112​

The EST 112 is one of my new favorite IEMs for regular use around the house. I found the Signature did a great job of keeping the lows nice and strong. The mids still sound fantastic and the Signature didn’t do much to bump up the treble which is the most lacking part of the 112. There was a little hiss coming from the 4.4 jack.

THIEAUDIO Clairvoyance​

One thing I love about the clairvoyance is how spacious and airy it sounds while still maintaining both a detailed and smooth sound signature. The Clair and Signature make a very awesome pairing IMO and I probably used the combo the most. The balanced staging of the Signature meant the Clair could really shine with its staging without anything sounding off. I got to about 12 o’clock on ECO. Those looking for something to spice up the top end of the Clair will probably wanna look elsewhere however.

Over ear pairings​

Focal Radiance​

The radiance is super warm and super relaxed with its tuning. I found the Signature to be a pretty good pairing. The Radiance isn’t super hard to drive but there was a noticeable difference when I went from the hip dac to the Signature. Lows maintain a nice thumpy impact and the mids still remain somewhat detailed but just a bit warmer than normal. Treble seemed to come in a little clearer and I actually really liked the combo. The staging had a nice balance of width and depth.

DCA Aeon 2 Noire​

The Aeon 2 Noire is a fairly well tuned closed back planar. It does lack a bit of life in the low end so it can come off somewhat lifeless on certain source gear. The same issue remains with the stock iDSD Signature. The overall sound is a little warmer sounding but the lows are still lacking a little life. When the xBass is activated, this brings some of the lifeless bass to a more dynamic sound without causing any distortion. Staging stays the same as compared to my daily amp that I use. Good pairing here.

Amps comparisons​

iFi iDSD NEO​

I’ll paste what I said in my iFi Neo review here.
The Signature comes in around the same price as the NEO. How does it compare sound wise? I think the Signature sounds way better than the NEO. The stock tuning from the amp is somewhat warm but with a nice airy sound. There seems to be more life to whatever headphones I plugged into the Signature after using the NEO. The biggest difference between these two devices will mostly be the inputs and outputs. More input and output options for the NEO which make it a better desktop amp. If you could care less about XLR outs, bluetooth in or coaxial in then I would say grab the iDSD Signature. I think it's worth it over the NEO if you can live without the things I just mentioned. You also get around 4 watts at peak with the Signature which is wonderful for a device so small.

S.M.S.L. SH-9/SU-9​

Both the S.M.S.L stack and the iDSD Signature were competed well here. Both have wonderful detail retrieval for their prices. The biggest difference will come down to staging and the sound signature of the two. The iDSD Sig is warmer and has an in your face sound. The S.M.S.L stack goes for the more treble oriented sound signature. The SMSL feels a bit better in depth as well. Both have a good amount of power output. The biggest thing will come down to what you need for your desktop. The stack has XLR outs, the iDSD Sig only has RCA outs. The Signature is also missing bluetooth which the S.M.S.L stack has.

Overall thoughts​

So at the end of the day would I recommend the Signature? I found no real issues with the Signature outside of wishing it had Bluetooth and a little lower volume output for the eco mode. The device is well built, works well as a desktop unit and can be moved around as a portable-ish unit. The power output is wonderful for a device this size and it sounds great. I think iFi did really well with this release. I had issues with the desktop NEO iDSD and recommended the Signature over it. I think this is a well rounded Swiss Army knife DAC/amp from iFi and the micro iDSD Signature gets a full recommendation! Good job to iFi and thanks for reading!

The packaging is very similar to the BL, its efficient and looks good too,
The Accessories inside includes:
- 6.35mm slimline adapter
- ifi Blue USB OTG cable, adapter OTG
- 2 rubber bands for stacking
- optical adapter
-ifi purple RCA cables
- carrying pouch
- USB-C cable
- manual
- warranty papers

Some specs:
iFi micro iDSD Signature
Input range 16 - 32 bit / 44.1 - 384 kHz PCM, 352 - 768 kHz DXD, DSD64, DSD128, DSD256, DSD512, 88.2/96/176.4/192kHz MQA
Suitable headphones impedance 16 - 600 Ω
Output impedance < 1 Ω (without IEMatch)
Maximum output power 500 mW (8 Ω, Eco mode)
1,900 mW (16 Ω, Normal mode)
4,000 mW (16 Ω, Turbo mode)
1,560 mW (64 Ω, Turbo mode)
166 mW (600 Ω, Turbo mode)
Frequency response N.D.
THD+N (@1 kHz) < 0.008%
SNR 115 dB
Crosstalk 79 dB

The signature is built well as with all ifi products care is taken to design something that will be a lasting a valued piece of equipment for years to come. The amount of controls are really impressive to me at least. I like the options and both front and rear IO doesn't disappoint.

I finished my review of the Diablo and was super impressed, I really wasn't expecting the signature to be this well rounded. That said it just checks all the right boxes for me, the IEmatch is one of the best implantations I've ever used, throwing at it my really sensitive all BA and lower ohm IEMs to find the worked exceptional. then finding normal mode was all I needed for the Fostex T50RP and other headphones. I was very pleased with the idsd ability to power everything high and low without a problem.
The Sound:
The idsd sig has a nice open and airy sound with that warmth I've come to like from ifi's Burr-Brown chips.
The Bass has details and texture it give a nice bottom end punch without over doing it. Bass boost or Xbass works well it might be one of the most useful Bass enhancers out of everything I have used , very tastefully done. the 3D works well too boosting the upper mids and lower highs to create a larger sound field.
Mids while warm have a great amount details to them, vocals are clean and filled with emotion and texture. Instruments have superb separation making this excellent for every kind of music.
Treble: Is far from harsh but maintains its details and sparkle, it is more neutral than bright and like the other frequencies is rich with micro details and a airy presentation.
Soundstage: Is naturally wide and imaging is very accurate with good separation.

Conclusion:
Battery life , build quality, sound and features make the iDSD signature the most well rounded portable or desktop DAC/ Amplifier I have used , its more than a jack off all trades as there is little if no trade off with its abilities.

iFi Micro iDSD Signature : Breaking All Barriers



Disclaimer:

I have bought this DAC/AMP with my own hard earned money at FULL PRICE and no one has paid me anything or supplied me with any review unit. So, everything mentioned in this review are purely my own based on my experiences with the DAC/AMP.

Introduction:

When I think about iFi DAC/AMPs, the first thing that comes to my mind it that it will be fun sounding. I have bought and used quite a few of iFi products and I loved most of them if not all. They are not the sterile type like studio analytical use - and iFi packs lots of fun & punch into their units that are are just great for music be it on the go or at home.

The iFi Micro iDSD Signature however is a compact powerhouse packed with loads of very useful features which make it very versatile for the price bracket it comes in - $650

Specifications & Technicalities:

Please find below the specifications as published on iFi website:

https://ifi-audio.com/products/micro-idsd-signature/


The iFi Micro iDSD Signature is a DAC/AMP for desktop or portable use with practically every feature iFi has implemented into their previous units that worked out well.
It has so many useful features that I am having a rough time finding how to describe them all.

The internal battery that can power the unit for up to 12 hrs depending on the IEM or headphone being used. The battery has a dual function here.
Since batteries don't need to convert AC power to DC, the unit can be charged even with a dirty power source because this unit has iPurifier technology built-in.
You don't need to worry about interference, noise, or voltage anomalies from the power source with this power source design.

Another great upgrade from their previous models is the upgraded iFi custom ultra-low noise OPamp OV2028 on the digital end and another iFi custom chip on the analog side which is labeled the OP2627. These are wide bandwidth capable chips & are low noise devices that very low distortion.

Also, iFi Micro iDSD Signature comes with DUAL Burr Brown DAC chips. Doubling the DAC chips results in a 3-decibel reduction in the noise floor and better channel separation not to forget the improved power supply circuitry design. Noise has been reduced to half the level of past models. Details retrieval and micro-dynamics have also significantly improved over other iFi models.


Also, some of the nifty features that it has but I'm not going deep into are below:
- Selectable Power Output: This let's you choose how much power you want for your IEM/Headphone
- Choose your IE Match Level: This let's you calibrate level of IE match depending on how sensitive your IEM is
- 3D & xBass: This can enable either holographic 3D like surround OR extra Bass or both.



Packaging & Accessories:


The iFi Micro iDSD Signature DAC amplifier comes inside a white box with an outer printed sleeve.


Inside the box you get a USB-C charging wire, a USB wire with full-size plugs for PC connectivity, a set of stereo RCA wires, a full-size USB gender changer, and the 3.5mm optical adapter. You also get a 6.35mm to 3.5mm headphone plug adapter. Some rubber rings to couple the unit to a source are also included. You also get a velvet carrying pouch.

NOW LET'S TALK ABOUT THE SOUND PERFORMANCE....

Items used for this Review:

IEMs: Shanling UA2, IFI Micro IDSD Black Label Signature

DAP/Source : @DUNU-Topsound ZEN, JH Audio Roxanne (Customized IEM), DUNU SA6, TRI Audio Starshine, @FiiO FH5S, @UniqueMelody 3DT, Tinhifi T5, BQEYZ Summer

Streaming Source: QOBUZ

Plugs & Connectors: Both 4.4mm balanced and 3.5mm connectors used for the review






Tracks Used:
The tracks I have used can be found from the below playlist that I have used and generally use for most reviews...


Let's now talk about the quality of Sound....

The BASS:

Due to the warmish tuning of the Burr Brown chip the bass is very detailed airy & textured all throughout. It is able to retrieve insane amount of micro-details while retaining quality & texture and rumble and punch. The bass packs some punch & thump also. Even the IEMs that seem to lack Bass body & details on some other gears seem to work well here. This is just a superb quality iFi has

The MIDS:

Mid-range is detailed, textured, airy with wonderful micro-details and nuances... one can easily get lost here.
It's just so smooth and beautiful... be it Guitar or Piano or Cello or Violin... there is excellent separation and each of the instruments sound very real.
Both Male & Female vocals sound great with ample amount of details down to the the tiniest nuances like breaths they take while singing can be heard clearly.

The Treble:

While it cannot be considered bright in any way - The iFi Micro iDSD Signature has superb Treble overall and in a very clean and non-fatiguing way.
Even IEMs that have some peaks in the treble region sound much nicer while retaining the details.
Treble here is full of texture, air, micro-details and rich sounding. The sound is just clean and refined here.
No peaks to be found anywhere - and it is quite forgiving for quite a few tracks that have unusual peaks.

The SOUNDSTAGE:

The staging capability is amongst the key strengths of this DAC/AMP. It is massive & immersive. Both in terms of width and depth.
Nothing artificial. only as much as the track requires it to. turning the 3D+ ON enables holographic staging... given that your IEM or Headphone is good enough to support it can be truly immersive.

Imaging & Timbre:

Sense of direction is spot n and also gives a notion on depth/height. You can clearly understand where the instrument of the voice sound is coming from and how far it is from you. In terms of Timbre it is amongst the best I have come across so far and very real.

Conclusion:

In short I have found this iFi Audio Micro iDSD Signature DAC/AMP to be very resolving, detailed, textured, natural and just superb sounding.
It is clearly the BEST from the house of iFi in terms of portable DAC/AMPs and likely the best in similar category also.
While the price bracket remains quite high - I would say that every penny is well-spent on this taking into account the value that it gives.
It's just a great sounding Desktop grade DAC/AMP that you can easily carry around with you.