Review: iFi Audio Pro iDSD

Firstly I would like to thank iFi for sending this unit on loan for me to review.

*disclaimer: This sample was provided on loan for the purpose of writing a review, no incentive was given to write a favourable review. All opinions expressed are my own subjective findings

Gear Used:
Pro iDSD > HiFiMan Sundara + HE500 / Beyerdynamic T1 2nd Gen / Various IEM's
Pro iDSD > Keces E40 > QED XT25 > B&W 606

Tech Specs:

Packaging, Build Quality and Accessories:
The Pro iDSD comes in a large white box, the same that comes with the rest of the iFi Pro range. Open up the top and you'll fine the Pro iDSD held tightly in place by foam inserts that will protect the unit during shipping. You will also find separate small boxes which hold the accessories. I really like the heafty yet simple packaging, it feels good and the unboxing experience is great.

The build of the unit is impressive, sharing the same aesthetics as the rest of the Pro range it has a thick silver aluminium shell with cut-outs for heat dissipation. On the front you'll find an LED screen along with the various knobs and switches that are all aluminium, along with the headphone outputs which feel solid. On the back you have all the inputs and pre/line outputs, again all of these use high quality sockets. On the bottom there is a large rubber mat instead of feet on the corners, I do find it to slide across my desk a little easier than units with feet.

Accessory wise you get a set of short RCA cables, USB cable, power supply, wifi antenna and a remote for the volume control. The Pro iDSD comes with everything you need really, and I cannot say it is lacking anything.

Well where do I start? The Pro iDSD is full of features including multiple digital filters (I would read the manual for these), along with DSD up-sampling. There are 3 gain settings and also 3 amplifier modes (solid state / tube / tube+). I do recommend you read the manual as it has tons of info on all these settings.

The remote only controls the volume, it is a shame it can't control the inputs. On the back you have small controls to change whether you want fixed or variable outputs from the analogue outputs (HiFi or Pro settings available).

There is a USB port and a memory card slot so you can connect an external hard drive or USB drive that has music on it. You will need an app on your phone to then access the music, and the Pro iDSD will need to be set up on your network for this to work.

When connected up to a network you can stream via Airplay or DLNA with an appropriate app too (MUZO / Bubble UPnP). The Pro iDSD is fully MQA compatible for those of you who use Tidal.
Also you can also now stream MQA files over network via the new MConnect app, you can find out how here:

Input wise you get a combo Coax/optical input (separate ports would have been good), along with USB input and AES. You also have BNC connectors for using an external clock (this is mainly for studio use). This is a fully digital device and there are no analogue inputs. Output wise you get 3-pin balanced XLR's and a pair of RCA outputs, this is fairly standard on this level of product now. On the front you have a 2.5mm balanced output, 3.5mm and a 6.3mm single ended outputs, these are for headphone use and iFi now make a version with the 4.4mm pentaconn socket.

I used the Pro iDSD as a DAC, and a DAC/amp with headphones and my hifi system.

First off we will start with the Pro iDSD in Bit Perfect mode as I found this filter to sound the most neutral and unaltered of all of them. In solid state mode I found the Pro iDSD to have a very even handed representation of the music, with excellent depth to the sound. In solid state mode, the Pro iDSD is a reference sounding DAC, the only thing it injects is a sense of space and air, and a sound that is extremely detailed yet refined. There is no noticeable boosting of any part of the spectrum, the sound is effortlessly clean and transparent yet it is devoid of the typical "analytical" and sterile sound that some DAC's can produce.

This sound signature is mirrored through the headphone output, with a wide soundstage, excellent layering and natural yet tightly balanced sound. The regular single ended output sounds excellent with a natural yet neutral tonal balanced, going to the balanced output you get more driving power which helps when using power hungry planars. Using the balanced output I get a little more impact out of my planar headphones, and slightly better soundstaging, but the sound signature stays the same.

Turning on Tube mode does what you would expect, and I really love this option. It adds a little bit of warmth and body without taking away detail. The 5670 tubes have a great ability of sounding very open and detailed yet with that hint of tube goodness that is subjectively pleasant. I found using Tube mode with some borderline bright headphones worked wonders, and the pairing of the HiFiMan Sundara with Pro iDSD in tube mode sounded incredible.

Tube+ mode doesn't add a lot more over regular tube mode and just sounds a little wider but not quite as tubey (don't mistake tubey for smeared and smooth). Tube+ does sound a like an good middle ground between SS and Tube so it does have its uses.

The Tube mode is also great when using the Pro iDSD as a pre-amp, it can reduce a little glare from your system and adds a little tube magic if you enjoy that in your system. My B&W 606's have quite an enthusiastic top end when paired with the wrong amp, so the Pro iDSD sounds excellent when in Tube mode with them, bringing out a little more natural and organic tonality.

Digital filter wise, I'm a firm believer in keeping things as they are and not oversampling etc... So for the most part Bit Perfect was my go to listening setup. And to me bit perfect is great, and offers the cleanest and most neutral sound. Up-sampling really didn't do much for me, it could be my ears or headphones but I know some people like to do it. However; the GTO filter may not measure well, but it sounds quite exciting and energetic adding a little bit more air between instruments and impact to the sound. I could see this as being a little fatiguing long term but it can be fun from time to time. Remember that the digital filters bring subtle changes to the sound, and do not change the underlying characteristics of the Pro iDSD.

I have recently reviewed the Matrix Audio Element M and it does a lot of things that the Pro iDSD does, but with a dedicated app which is really handy. When it comes to pure sound quality I find the Element M to reproduce things with a neutral and effortless sound signature, everything is incredibly well balanced and detailed yet never harsh. I find the Pro iDSD to be a tiny bit cooler in tonality with micro details being pushed forward a little more. The Pro iDSD does however have the external clock options, along with different gain options and a tube stage. Both are superb options and I can easily recommend either, it all depends on if you want the added tube stage really, although having separate optical and coaxial inputs on the Element M is really handy (TV and CD player plugged in at the same time).

Conclusion: As with most iFi Gear, the Pro iDSD just gets the job done, and does it very well. It is a neutral and detailed DAC with excellent soundstaging, layering and resolution. Turn on tube mode and you get a little hint of tube magic without masking the finer detail. The Pro iDSD is versatile and flexible, allowing you to stream and play files from a harddrive/SD card along with accepting most of the current digital inputs. Nice work from iFi as always, a well thought-out product that sounds superb.

Sound Perfection Rating: 9/10 (brilliant all in one unit that's both looks and sounds great)