iFi audio Pro iDSD - Standalone. Streamer. DacAmp

General Information

iFi Audio Pro iDSD is a DAC, a headphone amp... and so much more!


The Pro iDSD is a 'state of the art' reference digital to analog converter. lt is able to excel in many scenarios - as a wireless hi-res network player or the central DAC in an expensive high-end home system, to quote just two examples. The on-board balanced headphone section means high-end headphones can also be directly connected to it.

Quad stack – interleaved Burr-Brown DACs
The iDSD Pro uses a Quad ‘stack’ of iFi’s Bit-Perfect DSD and DXD DACs by Burr-Brown in a custom ‘interleaved’ configuration. This enables a total of eight pairs of differential signals to be used and mixed – four pairs of signals per channel.

All signals to the DACs are re-clocked with the low-jitter Global Master Timing® master clock derived from the AMR DP-777 DAC.

The DACs operate ‘Voltage Output Mode,’ giving >119dB dynamic range. All filtering is passive, using a fully-balanced third order capacitor/inductor/capacitor filter, rather than active, feedback-based circuits, to remove ultrasonic noise. (Active filters struggle with the amount of ultrasonic noise and RFI they have to handle and at a few 100kHz they can lose the ability to filter noise at all, which is precisely where a lot of noise is present.)

Using passive CLC filtering directly after the DAC means that the following analogue stage is not required to handle ultrasonic noise and RFI originating from the DAC process.

Studio Grade Remastering DSD1024
For the first time, Pro iDSD brings Studio Grade DSD1024 remastering to the mass. Now one can remaster all his/her music to a superlative DSD1024 format just like in a recording studio and enjoy the ultra-high resolution it provides.

For the DSD1024, if the MultiBit DAC is one half of the ‘heart’ of the Pro iDSD’s digital engine, then the other half is surely the Crysopeia FPGA. This is where we believe FPGA excels, by handling the remastering duties to attain the DSD1024 audio format. In fact the Pro iDSD can handle all audio formats to to DSD1024 or DSD512 or PCM 768kHz with user-selectable digital filters.

XMOS 16-Core X-Core 200 with large memory buffer for all digital inputs
The Pro iDSD features the new XMOS XU216 X-Core 200 Series 16-Core processor,with a maximum of 2,000 MIPS (two billion instructions per second) calculation power in dual-issue mode as a USB interface.

All digital processing is Bit-Perfect, without employing ASRC or up-sampling unless digital filters are explicitly selected. It can decode signals from all Inputs, from USB (up to 768kHz/DSD512), AES/EBU or S/PDIF (up to 192kHz/24Bit) and Wifi/Network/Mass-storage (up to 192kHz/32Bit).

A variety of digital filters (including Bit-Perfect mode without digital filtering) are available.

All inputs (including USB) are galvanically isolated and the USB input is self-powered. The SPDIF inputs use technology derived from the AMR DP-777 including a new, solid-state implementation of the HD-VDi, memory buffer and the Global Master Timing® clock system.

Recording engineers please note that the Pro iDSD supports the AES3id-based DARS (Digital Audio Reference Signal) as recommended in the Audio Egineering Society’s published AES11 standard.

Femto Precision GMT Clock & Reclocker
For all inputs data is sent to the aforementioned Memory Buffer, which iFi describes as ‘large’ and ‘elastic’. Here it is de-jittered to eliminate any transmission of source jitter to the DAC output. The data from the Memory Buffer is further re-clocked by with the low-jitter Global Master Timing® clock, which also drives the X-Core 200 & FPGA.

External Clock options and Synchronisation
For synchronization in recording studios the iDSD Pro supports AES3id based DARS (Digital Audio Reference Signal) as recommended in the Audio Egineering Society’s published AES11 standard. And if you happen to have a really good atomic clock (at least a Sanford Research Systems PERF10 should be used) this can be used as to further elevate the iDSD Pro over the internal clock system.

Wireless Playback Engine
With LINKPLAY™ WiFi/network playback, built-in Spotify and Tidal, and wide protocol support for 32-Bit/192kHz and DSD64, the Pro iDSD can directly link to a router for online music play. This gives it the option to:

• Play direct from SD card
• Link to router and directly steam (TIDAL/MQA, Spotify etc)
• Use DLNA via music stored on HDD

Full Galvanic Isolation
This is one of the ‘holy grails’ of computer audio. All inputs are galvanically-isolated (including USB). This is the same level of execution as found in the AMR DP-777 Digital Processor. The USB input section has its own separate power management system with multiple regulators and filtering operating from the galvanically-isolated voltage generated to power this section.

As the USB Input is self-powered, it does not draw power from the USB bus, making it quite impervious to after-market add-ons.

Tube/ Solid-State Real-time Switching
Compared to high-end headphone amplifiers, the tube stage of the Pro iDSD is different in two-ways. First, we don’t use good-quality 6922s or similar. Instead we use the very best; General Electric 5670 which is the premium variant with a different pinout.

For the first time, one can enjoy both the sound of Solid-State and Tubes in a single package (rather than as an ‘Effect Type’ add-on within an otherwise conventional solid-state design) and be able to switch in real-time. For some recordings and headphones/loudspeakers, Solid-State may sound ‘more lively.’ For others, Tube and Tube+ (especially Tube+) will sound more ‘luxurious.’ Select the one that sounds best for that particular moment, be it the recording, the mood or even the weather. After all, enjoying music is an experience to be savoured and not a scientific research exercise.

We haven’t stopped there. We are tube lovers and we appreciate sometimes there is a need for even more tube-like sound, there are two tube settings – Tube and Tube+. The Tube+ position reduces overall loop-gain and thus negative feedback to the minimum. This gives a different trade-off between the tube’s natural harmonics and the transient performance.

Class A Solid-State, J-FETs and Fully-Discrete
The Solid-State amplification section of the Pro iDSD is just as seriously executed as the Tube amplification section. It is the on the lines of the Pro iCAN.

The amplifer audio circuit is a development of iFi’s revolutionary ‘TubeState’ design. It is fully discrete, fully-balanced with either tube or J-FET input switchable, bipolar second stage and MOSFET-buffered bipolar class A Power stage. The resulting circuit may be best described as a ‘tri-brid’ where each device is used to greatest sonic advantage while minimising any drawbacks. Furthermore, the circuit is pure DC coupled to avoid using any sonically-degrading coupling capacitors. All of these are far from ‘run of the mill.’

Alps 6-Track fully balanced motorised Volume control with servo system
The Pro iDSD has a premium Japan Alps motorised rotary volume potentiometer. This is the ‘6-Track’ version with 4 tracks used for a true balanced volume control.

ELNA Silmic Capacitors
To maximise dynamic performance, especially with bass, the analogue stage is backed by audio-grade ELNA Silmic Capacitors located within a few millimetres of the audio circuitry supplied. Elna Silmics are used in the final stages of the main DC bus which is filtered using multiple stages of inductor/capacitor filters.

To boot, Elna Silmics are usually only found in components that cost far more as they considered ‘boutique’ components yet we consider them a ‘must have’ to achieve the best sound quality.

ELNA Dynacap Low Impedance Super Capacitors
The digital section is powered by a bank of Elna Dynacaps ‘Super Capacitors’ totaling 6.6 Farad (6,600,000uF). iFi uses Elna Dynacap DZ (TM) Super capacitors because they have 400 times lower internal impedance than common grades of super capacitors. This exceptional low impedance means they release energy much faster than other super capacitors.

Power Supplies
Using classic tube design, brought up-to-date with 21st Century technology, all incoming DC is converted to a high-frequency waveform then rectified and filtered by a choke input capacitor filter. This produces a first-level DC bus from which all further voltages are derived. The circuit also generates a galvanically-isolated power supply voltage for the USB input circuitry.

The digital section is powered by a bank of Super Capacitors totaling 6.6 Farad (6,600,000uF). iFi uses Elna Dynacap DZ (TM) Super capacitors because they have a 400 times lower internal impedance than common grades of super capacitors.

Latest reviews


Headphoneus Supremus
Pros: Size.
Sound-so tunable!
Build quality.
Ability to play for days with all of the controls!
Cons: Base slides when it is stand alone.
We do not have a better look at the tubes.
Remote is small, but functional.
Cost to some?
iFi Pro iDSD ($2499usd): So good, I bought it…last year.


iDSD website:

Amazon site (direct link from iFi site): https://www.amazon.com/iFi-Audio-iDSD-Music-Streamer/dp/B07C54B88P/ref=sr_1_fkmrnull_3?keywords=desktop+usb+headphone+dac+amp+mqa

Dedicated, ingenious, childlike, kicking, beautiful, understated, talented, & taunting

iFi needs little introduction by now, what with the hugely successful micro iDSD Black Label, x-series portables and nano components as well. Throw in all of the cable options & DAC’s and the AMR-Audio subsidiary out of Accrington, UK presents itself well. Seemingly moving to the smaller and smaller more portable options, the iDSD Pro and iCAN move iFi into AMR-Audio range. Successful would be an understatement, and often given as products of the year, the iDSD Pro follows that legacy accounting well to the heritage.

I have several iFi pieces of kit. I have a stack with the iTubes2/iDAC2/micro iDSD BL, which I dearly love. I still use them often. But given the opportunity to try the iDSD after the iCAN, I found that the Pro truly can replace the stack. That said for less than half the price, the stack is incredible. But this is about the iDSD, and it simply put is superb. With so many functions and hook ups, I do not think I have even tried all to be honest.

So, after the extended review time, I chose to purchase the unit. As too often happens with iFi products I demo, I purchase them. Sigh, my wallet laments, but my sound espouses goodness. Paired with the iCAN, I imagine the sound to be quite good (OK, better than quite good), and I have noticed that several have the combination. The iDSD works solo for me, and that is just fine, especially when hooked to other gear I have. And, I am just fine.



Sample rates:PCM up to 768kHz
DSD up to 49.152MHz (DSD 1024)
DXD and double-speed DXD (2xDXD)
Inputs:USB (required for DSD, DXD and sample rates above 192KHz)
AES3 (XLR – single link)
S/PDIF (coaxial/optical combo)
BNC multifunction (S/PDIF in or sync input)
Outputs:Balanced XLR at 4.6V (+15.5dBu – HiFi) or 10V (+22dBu – Pro)
Single-Ended RCA at 2.3V (HiFi) or 5V (Pro)
Headphones 6.3mm & SE 3.5mm Jack at 0.55V/2.1V/5V
Headphones BAL 2.5mm/4.4mm Jack at 1.13V/4.6V/10V
Headphones out 1,500mW RMS X 2 @ 64 ohm, 4,000mW max. 2 X @ 16 Ohm
Headphone Output Impedance:Single-Ended (S-BAL): < 1 Ω
Balanced: < 2 Ω
Volume control:Balanced (6-gang) Alps potentiometer, motorised with IR remote control
XLR/RCA outputs can be selected as fixed level or adjusted
6.3mm headphone jack is always adjusted
Other Functions:Various digital and analogue filters can be selected for DSD and PCM up to 384KHz
PCM Filters:Bitperfect 44.1 – 192kHz, always used for 352.8 – 768kHz
Bitperfect + 44.1 – 96kHz
Gibbs Transient Optimised 44.1 – 384kHz
Apodising 44.1 – 384kHz
Transient Aligned 44.1 – 384kHz
DSD filters:fixed 3rd order analogue filter @ 80kHz with correction for DSD’s -6dB gain
Gain (headphone section):user-selectable: 0dB, 9dB and 18dB
Dynamic range:119dBA (solid-state, PCM, -60dBFS)
Output powerPro iDSD 4.4mm socket. (16 Ω, balanced/single-ended): >4200mW /1>1,575mW
Pro iDSD 2.5mm socket. (16 Ω, balanced/single-ended): >4000mW /1>1,500mW
Output voltage(600Ω, balanced/single-ended): >11.2V / >5.6V
Input voltage (Pro iDSD):DC 9V/6.7A – 18V/3.35A
Input voltage (iPower+):AC 85 – 265V, 50/60Hz
Power consumption:< 22W idle, 50W max.
Dimensions:213 (l) x 220 (w) x 63 (h) mm
Weight:1980g (4.37 Ibs)



1. Quad-Core Burr Brown MultiBit/DSD hybrid DAC supporting DSD1024 and PCM768kHz
2. Studio grade DSD1024 remastering (Crysopeia FPGA Digital Engine)
3. Wireless DLNA/Airplay™/Ethernet Hi-Res Playback
4. User-selectable analogue stage: Tube or Solid-State
5. Master Quality Authenticated (MQA) playback
6. Global Master Timing femto grade clock system with external clock input options
7. Five filters: Bit-Perfect/Bit-Perfect+/Gibbs Transient Optimised/Apodising/Transient Aligned
8. Fully discrete passive LC analogue filtering
9. Zero Jitter Memory Buffer and Galvanic Isolation for all inputs
10. Discrete headphone/line amplifier
11. Balanced inputs and outputs
12. Galvanic isolated ultra-quite power supply with super capacitor


Gear compared/used:

Questyle CMA 12 Master ($1999)
iFi stack of iTubes2/iDAC2/micro iDSD BL ($1400ish)
Auris Audio Euterpe ($1599)

Audeze LCD-3
ZMF Eikon
Mr. Speakers Ether-C Flow 1.1
Sendy Avia
Campfire Audio Cascade
Verum Audio Verum 1

Empire Ears Legend X
Noble Savant II
CTM Da Vinci X

MacBook Pro
XDuoo x10t ii
Questyle QP2R
Shanling M5s

Songs used:

Van Morrison: Three Chords & The Truth
Tedeschi Trucks Band
Twenty one pilots: Regional At Best, Trench
Big Head Todd & The Monsters: Beautiful World, Midnight Radio
Bob Marley
Ziggy Marley
Roger Daltry
Los Lobos
Los Lonely Boys


Coming in a large white-sleeved box, the Pro comes well packed and well-endowed with goodies. With specs laden on the bottom, and the types of music on the bottom, along with pictures on top; one could easily spend much time looking at the box after hooking the Pro up. One look at the back and you understand what a mighty critter this is. And I will again state that I have not tried all of the options.

As per typical iFi, once the sleeve is off you have a snow-white box replete with silver iFi labeling. Clean and clear, I like the simplicity. Opening the carton, you are met with a protective foam insert to protect the Pro. Taking the wrapped Pro out, there is a smiley face complete with wearing headphones and the message “thank you.” Lol, a nice touch.


Several boxes underlay the Pro, with the accessories, and power pack/cord inside. With an included dual RCA (in purple!!!) cable set along with the ubiquitous blue iFi device usb cable, there isn’t much else included. But when you think that you already have two cables you have a very good start. My XDuoo came with a mini-xlr to xlr, which hooked directly into the xlr source, so I had three options. As a fourth I used an iFi Mercury 2.0 cable, which I won. I used that to hook up to my MBP as well.

Initial set-up:

Hooking the Pro to my MBP first using a dual RCA to single 3.5 cable, the MacBook easily recognized the iFi when brought up as “headphone port.” Hooking the Mercury cable up and a micro-usb adaptor, the MBP recognized the iFi as an iFi. Easy as eating a pie. Using the input switch allowed quick changes between multiple sources. I would often have the MBP and another source hooked up such as the XDuoo or a DAP.

Once you turn the iFi on it goes through a system check, with the iFi Pro logo in the top left blinking orange until the tubes heat up enough as well as the cycling through the menu. Turning to green you are good to go. The process usually took about 10 seconds total. The unit does remember previous volume as well, with the knob actually moving to the level it was when turned off. Of course, this only occurs if you turn the unit down after turning off. I will admit that watching the orange glow of the tubes come on is a simple pleasure I enjoy, and the “looking glass” fisheye on top makes for an voyeuristic approach. With the curvaceous opening on top mimicking the orbits of planets around the sun you get the central sun look through the fisheye. Psychedelic and astronomic at the same time. Coooolll.


With a curvaceous top as well, one is left with a somewhat unfinished feeling. I understand the iFi want for different shapes, but having a dead flat front cover, with a tabletop smooth top line you get mismatched curves. At first glance one might even think that the fit is not quite right. But it is. When thought of in the iFi vein, you get the singularity of design, which is their trademark. There is nothing on the market, which looks like the micro iDSD Black Label, and you could certainly say the same here what with the curves. In the end, I like it.

Playing Van Morrison’s In The Dark Night Of The Soul, through my Cascade’s, I immediately appreciate the dark tonality of the tubes. Just like the iTubes2, you can run full-on tube sound, a gentler mix (SET), and solid-state (Push-Pull). I love tube sounds in the portable market, especially after listening to the vaunted (RIP) Apex Pinnacle 2 and my music. Stunning, extraordinary, exemplary, superb are words too soft to describe the Apex. The iFi Pro does not fall that far behind to me but does make me think of the welcomed two weeks with the Pinnacle2. Played at DXD 768, with a 9dB gain, the sound was wonderful. I immediately appreciated the sound, but also quickly realized that for much of what comes on the Pro I would be out of my element. In that regard, I would have to utilize what I could with the three cable set ups.


From the manual:

The Pro iDSD (just like the Pro iCAN) is a one-of-a-kind product that is able to switch between:

'Solid-State' - a purely solid-state J-FET based circuit of fully discrete Class A topology.

'Tube' - the J-FET circuitry is switched to an all-valve Class A section based on 2 x GE5670.

'Tube+' reduces available negative feedback to a minimum. As a result, a greater amount of the tubes natural harmonic distortion is produced (even order harmonics dominate).

Headfonia mentions the lack of Bluetooth, and I do miss that, but when taken as a desktop setup with wireless DLNA capabilities as well as the multitude of other options, it is not really needed. If need be, hook up a BT source, connected to another source and you would have it. But one might wonder why you would degrade the sound as such.


More about the options:

Simply hooking up a source gives you many options with which to fine tune your listening pleasure. Keeping the Pro close would be a good bet, as you could happily change the gain level as well as tube/solid state set up ad nauseum. Changing the filter setting gives more options, and even these tired ears can hear some difference amongst the options. Not only does the “filter” knob rotate to give differing options from BitPerfect to BitPerfect+ as well as three others, you can push the knob in to change the mastering level. Leave mastering off and you get how the song was recorded, which does change between songs on the same album. Pushing once changes the level to DSD512 (which on TWP Trees) yielded 22 MHz DSD). Push again and you have DSD1024, 45 MHz DSD. The brightest option to me (without volume change) was the original. So, when upsampling, the volume is lowered a bit.

Cycling through the five digital filters I found myself using the Gibbs Transient Optimized (GTO) setting the most. I found the treble to be lifted a bit, without too much sparkle, matching the corresponding darker tube tone well. A definite Yin-Yang sound to me. Complimentary indeed. My second choice was Bit-Perfect+ due to the roll-off correction.


‘Bit-Perfect’ – No digital filtering is applied, one tap.
‘Bit-Perfect+’ – No digital filtering is applied, one tap, SINC roll-off is corrected.
‘Gibbs Transient Optimised’ – Minimum filtering, no pre-ringing, minimum post ringing, 32 taps.
‘Apodising’ – Modest filtering, no pre-ringing, modest post ringing, 128 taps.
‘Transient Aligned’ – Max filtering, max pre-ringing, maximum post-ringing, 16,384 taps.

Rounding out the front is the volume wheel, with very fine feel and adjustment, although using the remote gives less fine tuning. One touch on the remote yields about 2 adjustments up or down by hand. Next to the volume are the headphone outputs, with 6.3se, 3.5se and 2.5bal. Since my purchase a 4.4bal model has come out, which cost $400usd more. I would assume there has been some other fine tuning as well. I have no qualms regarding the lack of 4.4bal as I have never had an issue with 2.5bal jacks and do feel those that have are most likely unlucky or not careful enough. I get it, accidents happen, but to me that should not be the reason for purchasing a 4.4bal. Enough on that.



I found the Pro eminently changeable and adaptable. With the multitude of source options as well as filtering/mastering options you have roughly 150+ listening options when all tuning variables are included. For those that do not like to tinker, you may find your optimized setting(s) and leave it be. That is pretty much what I did but will admit it was much more fun than I thought changing the bits and pieces.

Using the XDuoo x10t ii transport, I found I liked the Xduoo even more. Since it is a dedicated turntable, one must hook it to an amp. Running it normally through my iFi xDSD, the iDSD Pro was a very nice treat. The clarity of tone was not diminished, but slightly enhanced with the full tube sound. I found myself changing the filter just for fun, but always seemed to come back to the GTO. Minimizing the change, I heard the dark tone of the tube come through, settling any dispute with a less than black background in a recording, which might have one. With excellent width of sound stage as well, the sound opened up to allow the vocals to take center stage. On TWP’s House Of Gold, Tyler’s Ukulele sounded bright and airy. When his vocals come through the middle, you cannot do anything but appreciate the center stage. The supporting cast of instruments coming in behind and in backing of the vocals tied together by the Ukulele. A thoroughly enjoyable airiness imbued an overall tone of a lilty atmosphere. Followed by Car Radio’s energetic full sound you get the sense that the Pro can adapt almost like a sentient being. And truth be told we are not too far behind that…

Using the Cascade’s in the above paragraph, one might think the Campfire Audio’s dark tone would be overwrought with dark tube sound. But, combined with the 2.5bal LQi cable and the XDuoo you find it open in sound more than other sources. Even in full-tube sound, the clarity belies the typical response of the Cascade (run on smallest filter for best bass quantity). What a wonderful trio.

Much time was spent on my MBP through the Mercury 2.0 cable and Tidal Premium. Almost as much time as on the XDuoo. I find the Premium sound of Tidal to be a bit dark of its own volition. With the Pro in tow, the sound again was a bit less dark, and more open. Going old school with Hurry Tomorrow from Los Lobos, the song provides a cacophony of variation. David Hidalgo’s vocals take on an almost ZZ Top-like quality, thrown in with an old Santana-like guitar riff. But when you listen, you know…its pure Los Lobos. An iconic group of which all should be exposed. The mix of guitar, drums, xylophonic sounds in the background and David’s vocals give you reprise and respite. This is the stuff of dusty east-Cali stuff, leading to that long desert road in Arizona on your way to west Texas via New Mexico. In an old Ford pick-up of course.


I did find that I had to raise the volume level about ¼ higher on the set up, but that is not all that much. Plus, I could have easily switched to the full 18 dB gain on the fly. When one does that there is a lag while the circuitry changes the option. One might be wise to lower the volume first. I will also note that using this combo gave various lags, niggles and quirks. Sometimes a loud switch between Tidal songs was had. I blame Tidal and the MBP because when using Pine Player on the MBP the lags were not heard. Something with the MBP/Tidal/iFi trifecta did not like each other.

I could also Airplay over to the iFi as an option as well. I found no problem with either setup.


I follow the above song with Los Lobos live version of Chuco’s Cumbia, playing it at much too loud a volume, but do not care. The clarity of which the acoustic guitars come forth is mesmerizing, enticing and make my feet move in time like an actual dancer. I am wrought with fantastic organic (yes, I wanted to use the other word…) sounds, which come across like the clear concise song you would find in a trip to the Mexican coast of the Pacific on a hot sultry night awash with dancing and much imbibing. It is a fantastically phenomenal sound with thorough depth and height to go along with the width. I am just along for the ride. After listening three times back to back, I must stop, for my typing becomes garbled, grabbled, gibberish. More in the morning. This is too good not to just sit and listen.


To go over all of the options, which the Pro can provide would take a 10k treatise. And frankly you do not want to read anything I write, which is that long. Suffice to say that 4k will usually be enough.


iFi iDSD Pro ($2499) vs Questyle CMA 12 Master ($1999):

Both of these winner’s approach sound as their mettle. But they approach it quite differently. Where the iFi is warm and provides much depth, the Questyle is almost as crystal clear as the finest Swarovski crystal from Germany. The true greatness of the Master to me is its ability to make clear pretty much every sound that comes through. That is not to say it does not provide a soul, or depth; but this is probably the cleanest sounding set I have ever heard. It’s Just My Heart Talkin’ is one of my favorite Los Lonely Boys tracks and an outstanding track for judging detail retrieval and clarity. Along with that, if there is any sibilance in the source/amp/headphone chain…it shows. And the Questyle passes with the self-assurance of a Le Mans 24-hour winner. There really is not anything terse to say about it. It performed admirably in any set up. The precision fits. Sound stage is quite good, bordering on a square. But that air between notes certainly makes up for any perceived “deficiency.” There are wider, there are narrower; but to combine an adequately big sound stage with that air is truly wonderful. Some might find the sound too analytical, but I say it is the neutrality that is driving that verbiage. This is probably the most neutral amp I have heard (again sample is limited).

That said, most often neutral bothers me for to me it lacks any real presence. There is definitely presence here. Throw on Los Lonely Boys Heaven and that song alone dispels any thought of analytical and dry. Bass is rich, vocals crisp like a Minot, North Dakota -35 F morning and a soul, which belies its neutrality. Want more neutrality? Switch the bias toggle up for pure class-A albeit a bit less power. This is one damn fine headphone amp. It really is. But it is so much more than that with all of its capabilities that to simply think of it as an amp would be an egregious error.

Whereas the iFi is dark in nature and I am OK with that. I love the tube sound and can fine tune the sound with the filters and other settings. But, if I had not already purchased the iFi, I would have seriously considered the Questyle. Even with that neutral clarity-driven tone. To me it is that good. A breath of fresh air, and it would be a superb dac/amp to consider for your home set up.


iFi iDSD Pro ($2499) vs Auris Audio Euterpe ($1599):

From my Euterpe review:
Compared to my iFi Pro iDSD, the Euterpe is simply spartan, utilitarian or void of options with which to tune the sound, save low/high impedance. The real fun is changing the tubes in the Euterpe. The iFi has switches and gizmos to do that. And if one wants to be able to change sound quickly, the iFi has few peers. Costing half-again what the Euterpe is, I find the sound comparable, but with many more options, the difference comes to the front. I can get that same tube sound and alter the sound signature of the music as well. With the Euterpe you are bound to the source. Not a bad thing, and really not meant for that many options. If I had heard both side by side before purchase, I would still have come home with the iFi. But based upon options, not a huge difference in sound.

Finishing my time with Boom Boom playing from BHT&TM, with John Lee Hooker, I get why I like the sound. There is a certain “dirtiness” to the song. A kick the seat back and find an open road to it, John Lee’s vocals simply give it that down home sound. The Euterpe adds to that dirtiness. Giving more. Adding a breadth of sound, which through tubes makes the sound oh so sweet. Follow that with Please Don’t Tell Her, and you understand from where Auris comes. One need only look at their website to garner a look at the more expensive wares. That technology used trickles down to the Euterpe well. And if this is their entry sound, one can only wonder what the more expensive units sound like. I am thoroughly satisfied with the Euterpe sound, and would consider it if there were more options to inputs and maybe adding a balanced-out option. But as stated earlier, as a stand-alone pure tube headphone amp, the Euterpe can muscle into the $1500USD quite well.


iFi iDSD Pro ($2499) vs iFi stack of iTubes2/iDAC2/micro iDSD BL ($1400ish):

My first genuine attempt at making a quality pairing, the stack still gets used. It is quite a fun sound, with the ability to play rocket ship pilot turning and fine tuning all of those knobs. I do not know, but I estimate there are well over four dozen different combinations to be had. I enjoy that aspect and can tune pretty much any headphone/IEM that comes in contact with the set. Plus, I absolutely love the BL alone as it is. That said, the Pro is better all around. With the option to add as much or as little tube sound as I want, this trumps the stack. To do so, I could still use the iTubes2 in the push-pull setting but there is less variation. The sound is crisper through the Pro, and the tube sound, well tubier. With all of the filters that can be applied, the Pro has few peers, even now. I have had several come its way, but the Pro still resides next to my station and gets the most use.



This review is long, long overdue. What started as an audition, turned into a purchase. And as such, I became quite lazy. I preferred listening, instead of writing. And due to Lawrance’s infinite patience, I could be lazy and wait. He politely emailed me again, which was the nudge I needed. I sit here pecking on my keyboard listening to twenty one pilots through my Legend X and the fabulous XDuoo x10t ii/iFi Pro iDSD combination. I have better DAP’s, but to me the XDuoo is about as pure as it gets. And as such, I can customize the sound at my beck and call through the iDSD. This is as good as it gets. Sound-wise, the Apex Pinnacle 2 is better (as it should be for $12k), but with infinite more options for tuning, the Pro iDSD is my choice for well over 60% of my listening. I will fiddle with the filters on a sing by song basis sometimes but leaving it to one setting is as much fun as the other.

And here is where the true benefit comes in, the ability to filter as I chose, the ability to source as I chose, and the ability to tube as I chose. That to me is what sold me on purchasing the Pro. And I do not regret it at all. This is still a fantastic unit (with 4.4bal option now), and truly one, which will stay in my rotation for a good long time. It is the basis of my comparisons, as it should be. And that gives me the kind of joy I have right now finalizing this. The sound is sublime, and all is good. Enough said.

Thank you to Lawrance for his continued patience, and to iFi for producing this gem of a critter.

Nice write up. Just got my unit yesterday and its a really decent piece of gear !!
I have yet to replace mine and now pair it with a used iCAN Pro I picked up. My need is satiated.😎
The Pro DSD is really a very good piece of hifi gear...
I sold my reference dac today, its that good here.
I like taking the dac out to several of my amps and with the PassLabs HPA-1 is a solid 10/10.
Its quite remarkable.
I am very tempted to buy the ican pro amp now as well and sell some of my other amps...


Headphoneus Supremus
Pros: Great feature set
Great sonic performance
Cons: A bit pricy
Best value is if you use all the features
iFi Audio Pro iDSD – Full Review

Hi Guys,
Pro iDSD – Verite
Today we are talking about another great Swiss Army knife type piece of gear. The iFi Pro iDSD! The companies flagship DAC. As with pretty much all of iFi’s products, it tries to bring both value and great sound to the table, and I think they have managed to achieve one and a half of those goals.
iFi Audio is a British company that was founded in 2012. It is a subsidiary of AMR Audio, which has a long history of making stereo equipment. iFi has always struck me as a company that focuses more on headphone and personal audio, but that does seem to be changing lately, and they are branching out into other areas (see the iFi “Aurora” all in one for an example of this.) Their products are innovative, and seem to prioritise functionality as well as sonic performance.
The pro line up is iFi’s flagship line, consisting of the Pro iCAN that we reviewed a few months ago, the iESL Electrostatic energizer, and the Pro iDSD. The Pro iDSD was the last in the lineup to hit the market, as iFi really did want
Pro iDSD – Verite
To do their best to get it “right” on the first go round. The Pro iDSD incorporates so many features, that it is actually hard to remember them all without looking at the companies specs page. The Pro iDSD is not *just* a DAC, but a capable all in one DAC/Headphone amp/Streaming solution. Similar to the Pro iCAN, it offers solid state, tube, and tube+ modes, as well as a fully balanced architecture. I was honestly worried that with all these features, the Pro iDSD may not have managed to sound great as well, but, for the most part, it absolutely does.
I will talk about what I feel the basic sonic signature of the Pro iDSD (used as a DAC) is, and then get into the variations on the sound, depending on which features you are using.
The Pro iDSD seems to slightly warm, and I really do mean slightly here. It isn’t dead neutral, and it certainly isn’t cold and clinical. However, with that being said, it isn’t as warm as some other solid state DACs I have heard, and certainly doesn’t venture into being mushy and gooey sounding, as some pieces of gear do. Dynamics, both macro and micro come across with convincing realism, and detail, both macro and micro was pretty darn good. Not the best I have heard, no, but far from the worst I have heard. I think the tiniest of micro detail may be better conveyed but other DACs, but the ones that I have heard that manage to do so are also quite a bit more expensive. I suppose it really depends on the features you prioritise, and what you are looking to get out of a DAC that matters when making your final choice.

For the first little while that I had the Pro iDSD, I experimented with the settings to figure out which I liked best. I ended up settling on using the bit perfect + filter, as well as the DSD1024 upsampling option. This seemed to bring a slightly better focus to the music, not making it sharp, but perhaps more incisive, with a tighter leading edge. Now, to be perfectly honest, I didn’t find the difference HUGE by toggling the DSD1024 upsampling on and off, but it did make a slight difference, so I went with it. Once I had decided on these settings, I left them alone for the most part. The Pro iDSD has SO many options to tweak, and play with, it can become overwhelming. I also think that if you are always changing all the settings, you might lose track of which change is coming from where, leaving you clueless as to what you really prefer.
So, with the settings decided on, I started listening to the solid state, tube, and tube + modes. These were quite similar to the tube settings on the Pro iCAN, which makes sense as it is exactly the same tube being used. Solid state mode actually ended up being my preferred mode for some music, mostly that which was fast paced and complicated in nature. Tube mode however, was probably my favourite mode out of the three. There isn’t a massive difference between the two, but tube mode seemed to have a bit better sound stage expansion in comparison to the solid state mode, at the expensive of the incisive leading edge of the notes with solid state mode. Tube + mode was curious, as I didn’t really notice it bringing anything positive to the sound signature over the regular tube mode, but it further reduced the incisiveness of the recording and also seemed to reduce the speed of the sound, albeit slightly.
Two settings that iFi didn’t include on the Pro iDSD are the “XBASS” and “3D Sound” features, that are present on the Pro iCAN. I reckon that they simply couldn’t find space and time to implement these features on and already feature laden device. Also, I suppose most people will at least consider using the Pro iDSD with the Pro iCAN, which does have the features, so there was no reason to include them twice.
The headphone amp section on the Pro iDSD is fairly competent, and can be used either in either unbalanced or balanced configurations. A recent post release update to the Pro iDSD has added the option of the 4.4mm Pentaconn connector as the balanced option, vs. The original 2.5mm jack. This is a welcome addition in my opinion, as it is a much more sturdy conductor, and will have a better lifespan. The Pro iDSD I had for review had the original 2.5mm balanced jack, and I have no cables with that termination, so I stuck to using the 1/4” TRS output. There are three gain options (0db, 9db, 18db) and up to 4w of output power (balanced) on the Pro iDSD. This means, for the most part, it will drive most headphones out there. Granted, for the HE6 and Susvara etc….you are going to get much better results with the Pro iCAN, but in a pinch, the Pro iDSD will work decently on its own. The headphone output struck me as remarkably similar to the Micro iDSD, albeit slightly more refined. However, there wasn’t much comparison when compared to the dedicated amplifier that the Pro iCAN is. Quite simply, if you have the means, or possess harder to drive headphone, I would highly recommend adding a dedicated headphone amp to use with the Pro iDSD. If, however, you are looking for an all in one solution, that will still do a competent job, you could do a lot worse than the Pro iDSD.
I did play around with streaming and the Pro iDSD, but I have to be perfectly honest and say that I didn’t venture too far with it. I don’t use streaming in my day to day listening to music, and wouldn’t like to speak about something I honestly don’t know much about. The small experiments I did end up doing went smoothly, and seemed to be consistent with my results from wired use. I reckon it is best for me to leave this option of use alone in this review, and allow those with more experience to speak to the streaming portion of the Pro iDSD in their reviews. I apologize for this lack on knowledge on my part.
Compared to some other DACs that I have had here, the Pro iDSD did fair quite well.
iFi Micro iDSD BL
The Pro iDSD brought a very similar tonal balance to the table, but did out resolve the iDSD BL quite handily. With that being said, I still think the iDSD BL offers a good value for what it does. The Pro iDSD also took the win on dynamic swings, and punch/impact.
Hugo TT 2
The Chord Hugo TT2 is quite a bit more expensive than the Pro iDSD. Using them both as purely a DAC, the TT2 is brighter, and perhaps more fatiguing. It does one up the Pro iDSD on raw detail, but I think that the tonal balance of the Pro iDSD may be more pleasing to a wider audience. The TT2 also out does the Pro iCAN in terms of being the better all in one unit, but as mentioned before, there is a significant price difference.
There are some concerns I have about the Pro iDSD. It may not be the best value proposition if you aren’t going to be using it as an all in one solution. The extra features add to the cost, and if you aren’t going to be using them, it makes little sense to purchase the Pro iDSD, given the other options that are out there on the market nowadays. The Pro iDSD is a good DAC, there is no doubt about it, but at times I felt as though it could have been better. Perhaps if iFi released a cheaper “Pro iDAC” in the future, that might be the better buy, if you aren’t going to use the headphone amp and streaming features.

All in all, I’d recommend checking out the Pro iDSD if you are looking for an all in one unit, but if you are looking for a pure DAC, you might be better served by a different, more cost effective option. With that being said, there is nothing wrong sonically with the Pro iDSD, and it does perform well as a standalone DAC. I think it has a pleasing tonal balance and does all the technical stuff pretty darn well. Maybe this is a case of “try before you buy” if at all possible. I think iFi may not have hit this one out of the park like they did with the Pro iCAN, but it certainly has landed pretty close to the back fence. Well done iFi!
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iFi audio
iFi audio
Thanks, lovely work!


100+ Head-Fier
Pros: Sound quality
Wide range of filters and headphone options
Wide range of playback resolutions including MQA
Very wide range of inputs and outputs
Cons: Control app is not one of the better ones
The user guide could benefit from a quick start section
This is going to be a series of evaluations of the Pro iDSD over a longer time than normal. It won’t involve a lot of technical information as that’s already out there not least of which from ifi Audio themselves. Here there are a bumper array of specifications, tech notes and video tutorials on set up to fill your head with.


Speaking of ifi Audio my sincere thanks must go to them for entrusting such a relatively costly device to me for an extended period.

I am aiming to look at setting up and running in, then comparing the Pro iDSD with the 2 systems I have available which bookend the Pro iDSD in terms of price and to see if it is poor/good/great value or even a great performer regardless of price. I also want to take a look at the control app and compare it to others as I feel this is often glossed over in what you might term professional reviews. I will try out a couple of different headphones that I use routinely and possibly also some IEMs but I don’t use these routinely as I much prefer an over ear headphone for comfort.

On that ifi Audio link there are also a collection of reviews and so if you do want to check out a good quality review by a professional I would recommend the one by John Grandberg as it seems to cover most everything you need to know and in a helpful informative manner.


Well the Pro iDSD is quite the device and while it is principally a DAC with enough options and settings to decode even the most exotic PCM/DSD/DXD files. It also has a prodigious set of filters with which to massage the sound from those files. It is also a streamer and runs on both Wi-Fi and Ethernet of which I prefer and exclusively use the former. Finally it is a headphone amplifier offering single ended and balanced connection together with options on gain level to suit sensitivity of the headphones or IEMs that you have chosen. As if that were not enough you can run the headphone amplifier in solid state, or Tube or Tube plus (like Tube but with minimal negative feedback) .

That’s just on the front panel (sorry there is a round window on the front to tell you the status of how you are connected and at what definition your music is being processed at).

The connectivity on the rear panel is mind boggling but in essence offers single ended/balanced/USB/SDHC/Coax/Optical/BNC/Power alongside aerial for Wi-Fi and output selection depending on if you are using the device in a HiFi or Pro audio setting. Going on past experience with ifi Audio products the set up “manual” has been quite Spartan but laid out in a logical progression. Now the manual is no longer Spartan but comprehensive, unfortunately however it is not the last word in logical layout. It took me a number of attempts to connect to Wi-Fi and then the other processes were fine but I just feel for the want of an easier layout or “fast start guide” it would have been much easier.

If I compare it to my 2 other systems from Lindemann (Limetree Network) and Auralic (Vega DAC and Aries G1 streamer) it was trickier to set up than either of those.

My main source of streamed music content is from Tidal as it is high quality and as it seems to provide all the music I want. I cannot comment on Qobuz as I have never used it at home.

The app which ifi Audio use for the Pro iDSD is Muzo and it was easy to access and download from the Apple app store. I believe it is equally available on Android.

I have to say that it connected to my Tidal account easily and was entirely stable. On the other hand it did not offer any flexibility in how it delivered “My Music” for example albums are listed by title alphabetically so you can’t change it to be by artist or date or anything else which is frustrating. I would have to put the Muzo app as third place against the Lindemann app as second and the Auralic LDS app as first. I’m told that MConnect or BubbleUPnP are other app control options but have not tried them as yet so will comment as and when I can.

I know it is often considered a small issue but I think it is of significant importance as it is fundamental in playing your music easily and smoothly and isn’t that why we are streaming and not playing a CD, LP or reel to reel tape?

Meantime I spent a few hours on deciding which settings I liked best with so many to choose from. This is not a definitive answer as you well prefer different settings depending on your taste and headphone choice. Given there are so many options I cannot conceive of a scenario where you could not find settings you liked best or at least better than the others.

I finally settled on Tube (who doesn’t love a triode or 2) and DSD 1024 with the GTO filter (also that seems to be the favourite filter of ifi Audio). The Limetree Network has far fewer options and so I went with DSD upsampling as Lindemann are big fans on the DSD format. The headphones used were Audio Technica ATH MSR7b (b for balanced) and Sennheiser HD800S. I started with the Audio Technica on single ended 3.5mm as both the Limetree and the Pro iDSD have this. Thereafter I moved onto the HD800S. I also tried the ATs balanced with the 4.4mm Pentaconn on the Pro iDSD to compare with its SE output. I don’t have a 4.4mm plug for the HD800S (yet) so will try that later.

In general terms and through both headphones there were several differences. The key differences between the LLN and Pro iDSD were speed, scale, sound balance and spatial reference.

On speed the LLN sounded lighter on its toes and gave the initial impression of greater speed. I will look into this more and see if it is true across more music genres as I think it might be due as much to the sound balance as anything.


Now scale on either headphone felt bigger on the Pro iDSD on the individual performers/instruments. It was more apparent on the HD800S but you could pick it up on the AT also.

I need to say that both headphones have in themselves a similar sound balance which is neutrality across the board and extended treble with a tight but lighter weight bass. This is the opposite of many traditional planar designs, but it is my preference.

In having said all this, the Limetree sounds lighter and brighter versus the Pro iDSD which has more warmth in its mids and extension at the bottom end. The Pro iDSD has a less sparkly treble which may be down to filter choice but I didn’t find a way to make it as sparkly as the Limetree. None of these traits are extreme or unpleasant but are only apparent on A/B comparison.

Finally on spatial cues both the DACs are strong. The Pro iDSD has the more focussed presentation of each of the instruments and vocals and it feels there is a bit more width and depth to the soundstage as well. In fact having tried the ATs with both single ended and balanced connection it is that kind of differential between the 2 DACs on spatial cues. The LLN sounds single ended and less 3D or hires in its stereo presentation than the Pro iDSD. If that makes sense?

As mentioned this is the first stage evaluation and I plan to try more music and options over the next days. Once I have got a better grip on the sound of the Pro iDSD I will compare it to my main system which has separate DAC, Streamer and Headphone amplifier.
Actually just yesterday the XLR to 4.4mm adapter plug I had ordered arrived. So I tried out the Pro iDSD with the AT MSR7b single ended and balanced and then finally the HD800S again both single ended and balanced.

The ATs sounded improved with a slightly stronger bass and a more focused stereo imaging in width.

The HD800S however soared. The top end became more sparkly and realistic, the bottom end more visceral although in both cases these were not extensions just better sounding versions of what had gone before. The stereo imaging now had real depth as well as width.

So now I finally feel as if I have begun to hear the value of the Pro iDSD over a less expensive device such as the Limetree.

I wonder if ifi Audio should bias the Pro iDSD more to people using the balanced operation more by adding an XLR socket and getting rid of one or other of the 3.5 or 6.35mm sockets instead.

Did anyone else experience this?
Lately I have been battling with the Pro iDSD to play with Tidal MQA (Masters) content. It seems that the Muzo app will not work with Tidal MQA at all and so it is necessary to use the M Connect app instead. I am trying to make it work but my iPhone wants to connect to M Connect via Airplay and I cant get it run on WiFi. Consequently still no Tidal MQA.

On the plus side of MQA I tried using an album I have on USB which was ripped from a UHQ CD MQA disc (also mine) and which has never played at MQA on anything I tried previously. On the Muzo app....surprise....24/178 wow. Actually it didn't provide a night and day difference but it did sound marginally better than the 16/44 stream from Tidal or indeed Qobuz.

None of that is the fault of the Pro iDSD as I am still undecided about the whole MQA thing. Anyway it has given me a boost to get to the bottom of the Tidal MQA conundrum.


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