Audirect Whistle

  1. Moonstar
    Audirect Whistle, Small in Size but Big in Sound
    Written by Moonstar
    Published Feb 26, 2018
    Pros - Tiny form factor,
    Lots of low profile cables/accessories,
    Plug and Play capability for Android and IOS,
    Pretty good sound presentation,
    Low to none hissing
    Cons - No independent volume control,
    No battery means additional battery drain for the source
    The Audirect Whistle, small in size but Big in Sound…


    1. Disclaimer:

    First of all, a big thanks to Audirect for providing me this free sample of the Audirect Whistle for review purposes. I am not affiliated with Audirect beyond this review and these words reflect my true, unaltered opinions about the product.

    The review was originally posted on my blog, and now I would like to share it to the Head-fi community.

    2. About Audirect:

    Audirect is part of Shenzen Micronetwork Technology Co., Ltd. located in Shenzen – China and is engaged since more than 5 years in the development, production and sales of portable DAC’s. The Whistle is the second generation there audio line.

    Official website of the Company

    3. Price:

    The Audirect Whistle DAC/AMP is sold for 99,00 USD

    Purchase Link:


    4. Introduction:

    The Audirect Whistle is a small Hi-Fi DAC and Headphone Amplifier created for people who are not satisfied with there onboard PC soundcard or the sound and output power of there Smartphone’s or Tablets.

    5. Package and Accessories:

    The device comes in small white card-box and contains the following items;

    • 1 pcs of Whistle PCM/DSD DAC/AMP
    • 1 pcs of Micro USB cable
    • 1 pcs of USB Type-C cable
    • 1 pcs of Lightning cable
    • 1 pcs of long profile 3.5mm to 3.5mm cable

    Audirect has put some nice accessories in to the package. Those are 3 digital OTG and 1 analog connection cables. The Lightning and USB Type-C OTG cable is a free bonus. When you plan to buy it separately you must spend normally 13.90 USD for the Lightning and 9.90 USD for the USB Type-C cable.






    6. Design and Build Quality:

    The Audirect Whistle is a very compact and small (better say tiny) device that has almost the same size of an AA type battery. It is very lightweight and is only weights only 12g.


    It has a triangle shaped design with rounded corners and has an all metal housing. The all metal housing is made of aluminum material and is very well made.

    The device has a smooth surface and is painted in one color; only the top and bottom corners are not painted and are appearing in silver metal color. The device is available in 2 different color options and those are gray and red. My review sample came is in red color.


    On the top of the device is the 3.5mm headphone/analog out that is compatible with 4 and 3 poled jacks.


    At the bottom is Micro USB digital out that allows you to connect it to devices with USB 2.0, Micro USB, USB Type-C and Lightning connection like Tablets, Smartphone’s, PC and MAC that supports external USB DAC’s.


    On one of the front surfaces are the Audirect Logo and two LED lights. The PCM marked LED lights up when a PCM conversation is in process and the DSD marked LED lights up when you play a DSD (Direct Stream Digital) file.



    7. Technical Specifications:

    • DAC : ES9018Q2C
    • AMP : ES9016
    • Frequency response : 20 – 30000Hz ( -0.15dB)
    • Distortion : 0.0004 %
    • SNR : – 128dB
    • DNR : +121dB
      Output Power Rating : – 115dB THD+N, 2Vrms into 600Ω
    • Output Power Rating : – 100dB THD+N, 49mW into 32Ω
    • Output : 3.5mm (supports 3 and 4 pole headphone jacks)
    • Input : Micro USB (from Micro USB, USB Type-C and Lightning)
    • Resolution : PCM 16 up to 32bit/384kHz sampling and Native DSD 1bit/2.8MHz/5.6MHz DSD
    • Demission’s : Length: 51.0mm Wide: 14mm Height: 14mm
    • Weight : 12g

    8. Hardware and Software:

    The Audirect Whistle is a small DAC but has some nice hardware specs. The Whistle has no battery and any physical volume control button/wheel.

    a) DAC Section:

    Inside the Audirect Whistle is the ES9018Q2C DAC of the company ESS Technology Inc.

    The ES9018Q2C is a 32-bit Stereo D/A Converter with Integrated Headphone Amplifier and Output Switch. The SABRE9018Q2C SOC (in short System-On-a Chip) is capable to deliver an SNR (Signal to Noise Ratio) of 121dB, THD+N (Total Harmonic Distortion) of -115dB.

    The ES9018Q2C SOC operates from a single +3.3V supply.

    The ES9018Q2C features ESS’s 32-Bit HyperStream® architecture that handles up to 32-Bit 384kHz PCM data via SLIMBus, I2S, or DSD-11.2MHz data.


    b) AMP Section and Drivability:

    The Audirect Whistle has an ES9016 amplifier of the company ESS Technology Inc.

    The ES9016 is an on board amplifier that is integrated in to SOC of the ES9018Q2C. The output rated of 49mW into 32Ω and 2Vrms into 600Ω. It was capable to driver my Audeze iSine20 and Audio-Technica ATH M50 to very loud sound volume levels.

    c) Battery Draining:

    The Whistle has less battery drain than the first generation of Audioquest Dragonfly and other devices like the Fiio E10K.

    d) Hissing:

    I was very surprised to hear such a clean sound output form such a priced device. I don’t know the performance of the first batch, but the Whistle is a great performer if you have a sensitive to hissing.

    The Audirect Whistle sounds very clean with some of my sensitive IEM’s like the HiFi BOY OS V3 and the DUNU Falcon-C, even in very high volume levels. I think that the Audirect team did a good job by making such silent device for this price.

    e) Compatibility:

    The Audirect Whistle works flawless with Windows PC, MAC, iOS and Android devices.

    The Whistle installs the required drivers at the first connection and everything runs automatically. A MAC device doesn’t need any driver installation.


    My Ipad Air 2 did automatically recognize the Whistle as a plug and play device.


    My Samsung Galaxy S8+ Android Smartphone is working flawlessly and doesn’t need any additional third party software.


    9. Equipments used for this review:

    DAC’s : Audirect Whistle, Audioquest Dragonfly Black

    Digital Source : Ipad Air 2, Samsung Galaxy S8+ and Dell 5521 Laptop
    IEM’s : Audeze iSine20, Dunu Flacon-C, HiFi BOY OS V3, TFZ TEQUILA1,
    Earbuds : NiceHCK EBX, HiFi BOY Dream

    Headphones : Audio-Technica ATH50M


    10. Albums & tracks used for this review:

    • Sebastian Ingrosso, Thommy Trash &John M. – Reload (Apple Music)
    • Michael Jackson – Billie Jean (DSF)
    • Casey Abrams – Robot Lovers (Tidal Hi-Fi)
    • Emmanuel Pahud (Claude Debussy) – Syrinx (Flac 16bit/44kHz)
    • Melody Gardot – Who Will Comfort Me (Flac 16bit/44kHz)
    • Aretha Franklin – I Say a Little Prayer (DSF)
    • Diana Krall – So Wonderful (DSF)
    • Otto Liebert & Luna Negra – Up Close “Album” (DSF) – Binaural Recording
    • Alboran Trio’s – Cinque Lunghissimi Minuti (Flac 16bit/44kHz)
    • Megadeth – Sweating Bullets (Flac 16bit/44kHz)
    • Opeth – Damnation (Tidal Hi-Fi)
    • Metallica – The Black Album (Flac 24bit/96Hz)
    • Lorde – Royals (Flac 24bit/48kHz)

    11. Supported Audio Formats:

    The Audirect Whistle supports the following formats that I have tested out during this review;

    Native DSD (64/128), FLAC, ALAC, APE, WAV, AAC, OGG, MP3, WMA

    12. The Sound:

    I have burn-in the device for approx. 100 hours before I wrote this review.

    Please note that this is a low budget DAC and all my comments about the sound quality are in consideration of this price range.

    Tonality / Bass / Mid / Treble / Soundstage & Imagine:

    The Audirect Whistle is a quite balanced sounding source with a hint of warmth that avoids making it sound too dry.

    I have use the Audirect Whistle with my Samsung Galaxy S8+ (Smartphone), Ipad Air 2 (Tablet) and Dell 5521 (Laptop).

    The improvements on any source I have plugged the Whistle was clearly noticeable. The first noticeable thing was a better authority in the bass department. The improvement of the sub-bass extension on my The Galaxy S8+ was immediately noticeable. It was able to provide a better sense of sub-bass power in the 20-50 Hz range.

    The Whistle has also the better mid-bass presentation and control. The quantity and quality is good enough to avoid any lose of definition. My Dell 5521 (Laptop) and the Galaxy S8+ have some problems to handle the speed of the mid-bass range, especially in bass heavy songs that need additional speed and control. The mid-bass improvement was best noticeable on my Dell 5521 that has an onboard soundcard. The Ipad Air 2 the best bass department right after the Whistle.

    The midrange of the Whistle sounds slightly more forward than the above mentioned sources. The midrange clarity is quite good and benefits form the clean background of the device. The biggest improvement was the detail retrieval on all plugged devices. The midrange improvement on my Dell 5521 was dramatically especially in the upper midrange; while the change in quality was less noticeable with the Galaxy S8+ and the lowest on the Ipad Air 2.

    The Audirect Whistle has some pretty good clarity in the treble area. It has the smoother upper treble register and it sounds also more transparent than all the three sources that I have mentioned above. The improvement is best noticeable on the Dell 5521 and less on the Ipad Air2.

    The increasing of soundstage is noticeable but not in a marginal way. There is some improvement for the depth on my Galaxy S8+ especially on the Dell 5521. The wide of the soundstage on the Ipad Air 2 is already for a tablet, but gets quite step further with the Audirect Whistle.

    13. Comparison:

    Audirect Whistle vs. Audioquest Dragonfly Black (v1.5):

    The Audioquest Dragonfly Black is USB Stick-Sized Digital-to-Analog Converter (DAC) that is also compatible with Apple and Windows PCs, as well as iOS and most Android mobile devices (requires Apple Camera Adapter or OTG adaptor for Android).

    Accessories, Design and Build Quality:

    The Dragonfly Black is a small device but is bigger in size compared next to the Whistle. The outer shell of the Dragonfly Black is made of plastic that has a rubber like coating that gives a nice touch feeling, while the Whistle has an all metal shell with a smoother surface. One thing that I don’t like about the Dragonfly series is the use of a plastic cap that maybe protects the USB male connector of the device but can be easily lost.

    The package of the Dragonfly Black includes only the leather case, no low profile cables for mobile devices that Audirect Whistle has already in the package.


    Hardware Comparison and Compatibility:

    The Dragonfly Black has the 32-bit ESS 9010 DAC with minimum-phase filter under the hood. The Audirect Whistle on the other hand uses the newer DAC chip of the ESS family the ESS9018Q2C.

    The Dragonfly Black has the advantage that there is no need for any cable if you use the device with a PC or MAC but makes is more bulky that the Whistle. The Dragonfly Black has also this nice colorful LED indicator with the look of a Dragonfly that shows which bit-rat is actually active. The Whistle has also two LED indicators one for PCM that is active for all bitrates (except of DSD) and one for DSD.

    The Dragonfly Black supports sampling rates up to 24-bit/96 kHz but doesn’t support DSD files. The Whistle in the other hand supports sampling rates up to 32bit/384kHz and has Native DSD capabilities for sampling rates up to DSD64 -1bit/2.8MHz / DSD128 – 1bit/5.6MHz.

    The Dragonfly Black doesn’t need any drivers for PC and MAC devices but needs and CCK (Camera Connection Kit) for IOS devices (that you must buy separately) but without the need to install any software, but doesn’t works great with Android devices. To pair the Dragonfly Black with Android device, you need an USB OTG (On the Go) cable (must be bought separately) and you should install third party applications like USB Audio Pro that costs additional money to active the hardware volume control. The Whistle automatically installs the drivers to your PC and doesn’t need any software for MAC, IOS and Android devices. The cables to connect to these devices are also included to the package that is a big plus.

    Both devices have nearly the same battery drain effect to the device they are connected.

    The Dragonfly Black has an output voltage of 1.2 Volts and has more output power than the Whistle that performs very well with IEMs.



    The Dragonfly Black’s sound signature reminds to this of the Chord Mojo, especially the warmth and musical sound presentation. The Whistle has the more balanced sound tuning compared to the Dragonfly Black.

    The bass on the DF Black has more punch and gives a nice hint of warmth. The Whistle on the other side has less bass impact but with better speed layering and control. The bass definition is nearly equal.

    The mids on both devices is sounding quite detailed and but after an intensive listening period with both devices, I have come to the decision that the Audirect Whistle has the better detail level for instrument and vocal presentation. The Whistles layering of mids is also superior compared to the DF Black.

    The treble range of both devices sounds quite controlled and with nice detail retrieval, that has a performance above this price point. The Whistle has more treble focus and sounds more lifelike, but the DF Black has the advantage with its better control in the upper treble register.

    The soundstage of both devices is above average not ultra wide or claustrophobic. Both devices have a nice sense of depth and above average performance for soundstage wideness.


    No doubt, the Audirect Whistle sounds much cleaner that the DF Black. The DF Black has a small amount of hissing with sensitive IEM’s, while the Whistle is the cleanest sounding DAC I have tested in this price range to date.


    14. Conclusion:

    The Audirect Whistle is a small DAC with a good build and sound quality that has lots of accessories (low profile cables) and almost no hissing that is a big welcome, especially in this price range.

    15. Pos and Cons:

    + Tiny form factor
    + Lots of low profile cables/accessories
    + Plug and Play capability for Android and IOS
    + Pretty good sound presentation
    + Low to none hissing

    - No independent volume control
    - No battery means additional battery drain for the source

    This review was originally posted on "Moonstar Reviews" :
      karanehir35 likes this.
  2. Zelda
    Audirect Whistle – Mini Portable DAC
    Written by Zelda
    Published Oct 18, 2017
    Audirect Whistle – Mini Portable DAC


    whi (1).JPG

    Technical Specifications
    • +121db DNR
    • -115dB TND+N, 2Vrms into 600Ω
    • -100dB THD+N, 49mW into 32Ω
    • Resolution: up to 32 bit/384kHz sampling or 1bit/2.8MHz/5.6MHz DSD
    • Dimensions: L: 51mm, W: 14mm, H: 14mm

    whi (2).JPG

    Price: U$D 99

    • Micro USB to Micro USB cable
    • Micro USB to USB Type-C cable
    • Micro USB to Apple Lightning cable
    • 3.5mm to 3.5mm Aux. cable
    whi (3).JPG


    The Whistle DAC is a very compact and well-built device. The outer material is made of metal, aluminum it seems, painted in either gray or red color (depending on the model). The surface is very smooth and despite the triangle shaped design the edges are well rounded.

    It is a very simple portable unit, with a Micro USB input connection on one side and standard 3.5mm output on the other. There are also a two Led lights to indicate the music format being played, PCM or DSD.

    whi (4).JPG whi (5).JPG


    The Whistle can be connected to a personal computer, tablet or smartphone. For Windows systems it is needed to install an extra software for the drivers. Unfortunately, it was not recognized with two of Samsung Galaxy phones I tried, but seems to work fine with iPhone devices.

    The Whistle volume is adjusted by the device it is connected to. With Windows PC it can get too loud already even before reaching the half of volume steps.

    whi (7).JPG

    Sound Quality

    The Whistle sound performance was tested with various kind of gears, IEMs, earbuds and portable headphones, like the Vsonic GR07, Dunu DK-3001, MeeAudio P2, Fiio EX1ii, VE Monk+, Asura and Zen, Sennheiser HD-25 ii and Grado SR80. The gain and improvement in sound were more noticed with the open earbuds and headphones rather than with the closed In-ear sets.

    Overall, the Audirect Whistle small DAC offers a fuller sound from lows to mids with a smoother yet detailed upper end. It shows pretty much no coloration to the sound, which is quite a good feature for any DAC, but brings out a more natural tonality. The bass is larger and better layered without showing a higher mid-bass quantity. Sub-bass extension was better noticed on with the HD25 and Grado sets as both benefit from some extra amplification. The midrange remains very clean and slightly more forward with a nicer texture for vocals. No real gain on instruments separation though, but it keeps the detail and positioning. Treble has a better control, especially with brighter sets, being better rounded and very slightly smoother overall. The less favorable improvements are in stage dimensions; it doesn’t sound smaller, but still not as wider as could be expected.

    Compared next to a similar DAC such as the Zorloo ZuperDAC, the differences are easily noticed. The Zorloo has a more v-shaped presentation with a warmer low-end and less forward midrange but with a wider soundstage, while the Whistle is cleaner towards the midrange and highs and more natural in presentation.

    Overall, the Audirect Whistle DAC is a very compact and comfortable device, fairly well built and easy to use. My only complaint would be the need of extra drivers which is a bit annoying for the 2017, and the lack of volume control. That aside, the sound presentation is still enjoyable for a small and simple audio gear.

    Lastly, my thanks to Audirect for providing the Whistle unit for review.
      ryanjsoo and B9Scrambler like this.
  3. ExpatinJapan
    Whistle while you work, Tralalalalalala
    Written by ExpatinJapan
    Published Aug 10, 2017
    Pros - Small form, transparent, easy to use, no cck needed, smooth, ess dacs and amps
    Cons - Cable is good but not great, no internal battery
    Audirect `The Whistle` Dac/Amp Review - Expatinjapan

    I give it 3.5 stars

    Audirect Whistle and Campfire Audio Jupiter
    The Audirect Whistle dac/amp is for use with iOS, Android, PC, Mac and your car.

    The DAC chip is ESS9018Q2C and the Amplifier is ES9016

    Updated new packaging.

    *Audirect has since updated the packaging. Those photos following my unboxing.

    The older original packaging.







    Cables galore: Micro usb to lightning, micro to micro and a micro to usb-c.

    A cable for use in your automobile.

    Apple Touch 6G, Audirect Whistle and Simgot EN700 Bass

    New packaging

    Back in black, paint it black...

    The Output impedance is <1ohm which means its friendly with multi driver BA IEMs.
    Audirect Whistle with Campfire Audio Andromeda, iBasso CB13 cable
    and Effect Audio Balanced to single end adaptor.

    The Audirect Whistle was tested with my ipod Touch 6, 128GB and mainly 16/44 FLAC using the Flacplayer app by Dan Leehr.

    ipod touch 6G and Flacplayer app with Audirect Whistle

    Headphone Jack out (only) - Flacplayer app

    The Whistle is an affordable DAC/amp with a ES9018Q2C Dac and a ES9016 amplifier so one would hope for noticeable improvements in sound quality over that of an ipod or smartphone and computer...
    The vocals are nicely presented, at times a bit forward of the music for my tastes.
    Stock cable, vocals forward - sounds fabulous, cymbals and high hats prominent. Sound stage seems to be more forward, vertical and less on the horizontal.Treble seems more prevalent. ESS signature sound.

    With the REI cable the music and vocals are more complementary, smoother, the sound stage becomes wider, deeper and more of a sphere shape, instrument separation and placement is greater, the overall experience more deeper and intimate.

    The ipod Touch 6G is an excellent dap itself, clear, detailed and with good definition. It lacks a bit of body and can get fatiguing for long periods of listening.
    With the addition of the Whistle into the mix it becomes more smoother, the music has more body to it, the low end is more present and fulfilling.
    The ipod Touch 6G and the Audirect Whistle share many sound signature similarities.

    I found the effect to be more noticeable the higher up the chain I went with various earphones.
    As with many of these devices often the difference isn't a night and day or `wow!` factor, more often the effect is incremental and more subtle. A fine tuning of the experience.

    I was able to listen at lower volumes with the Whistle rather than have to crank up the volume through the headphone jack to have a decent sonic range.
    It did take quite a number of sessions to unravel the Audirect Whistle benefits.

    At first I wasn't sure what I was and wasn't hearing (coming from TOTL daps), it took a few days listening to confirm what I believed my ears were hearing, and to isolate the various benefits of the device.

    The Audirect Whistle tempered the overall experience, giving more body to the music, reduced hiss and added a smoother element to the overall listening experience resulting in less fatigue during longer listening sessions.


    *The Whistle new batch will have a better sound quality, because they found that the capacitor at the "COG" level will be improved.

    With a laptop

    With my Apple Macbook pro I found benefits such as no hiss when using the Whistle, whereas when I used the headphone jack of the Macbook I experienced hiss.

    The Macbook pro already reproduces decent a point. The Whistle takes it quite step further in terms of resolution, smoother, more body, greater separation, sound stage is increased and my overall listening experience was certainly more pleasurable. More lively and engaging.

    For Macbook I found I didn't need to install any drivers for the Whistle to function.
    Windows computers running Windows 10 don't need a driver so I have been told. Windows 7 needs drivers installed.

    Using VOX music player for Macbook

    At US$99 it is one of the lowest priced dac/amps out there on the market.
    With no need for a CCK for idevices it makes it simple to use.
    Its small form and lightweight body means it is easy to carry and use.



    The Audirect Whistle is a very affordable DAC/amplifier that can complement many an existing system.

    I wish I had an Audioquest Dragonfly (Black) to compare with as they both retail for the same price.

    One thing that puts the Audirect Whistle in good company (Cozoy REI, CEntrance DACportable to name a couple...) is that they don't require an Apple CCK to function.

    The Cozoy REI has more smoothness, detail, separation and subtlety, the CEntrance DACportable has more power, detail and low end body. But the price differences are quite wide and distant between them and the Audirect Whistle so that is to be expected.

    The Audirect Whistle has that clear, (slightly) highs focused signature often associated with Sabre Dac devices.
    The effect is one of increased clarity and transparency, more noticeable with analytical listening or longer sessions. It is not a strong change in that it does not possess any coloring to be easily heard, but more of its intended aim to clean up, concentrate and contain the musical reproduction.

    I think a better lightning cable would improve clarity, detail and overall sonics. When used with the lightning cable that comes with the Cozoy REI the experience improves in thats its smoother and richer. (Yes, yes. I know its all 1s and 0s and that it shouldn't make a difference....buuuut....).

    Red or Black? I chose red so I could find it easier. :wink:

    Don`t expect to use this with a low end set of earphones and have them magically transformed, I really noticed the Whistles performance with the Andromeda, less so in the budget to just below the mid fi bracket.
    (With the ipod touch).

    Its hard to say whether its the DAC or the AMP, or the DAC and the Amp combined making the difference. As we know a bit of extra amplification itself can do wonders.

    That it eliminated the hiss (with my macbook) might be a major appeal point for some.
    perhaps this might be replicated on other devices also? Smartphones etc...I don't know.

    I would have liked to have more variety of sources at my fingers to test the Whistle more, in particular smartphones that have poor quality music playback.. at an uneducated and untested guess the Whistle might help - using my macbook as an example.

    Not included is a Micro USB to USB-A cable for use with a computer, but I think we all have a few of those at home.

    *The Whistle new batch will have a better sound quality, because they found that the capacitor at the "COG" level will be improved.

    Overall the Audirect Whistle comes in at a decent price, my regret is I don`t have the Dragonfly black to compare with. It does produce a pleasing effect in that the music has more body and it adds a fullness to the music, also it gives a smoother and less fatiguing experience.


    Thank you to Audirect for sending Head pie the Whistle Dac/amp for review.