IKKO Heimdallr ITB03 Review





IKKO Heimdallr ITB03 BT & USB DAC/Amplifier Review




IKKO Audio (IKKO Technology Co. Limited) is a relative new Chinese brand that designs & develops Hi-Fi components like In-Ear Monitors, Portable DAC/AMP, Docking Stations and many more.

The Heimdallr ITB03 that I will now review for you is the companies first Portable Bluetooth & USB DAC/Amplifier, which is an Ultra-Portable and very capable All-in One solution that is compatible with a wide variety of platforms including Android, iOS, MAC OS, Windows 10/11, Nintendo Switch, Sony PlayStation 5 and Microsoft XBOX devices. The Heimdallr ITB03 is equipped with 2x Asahi Kasei AK4377 DAC Chips and features 3.5mm Single Ended/Optical and 4.4mm Balanced (TRRRS) outputs. The Bluetooth connection is powered by Qualcomm’s latest and most advanced QCC5125 BT Chip, while the XMOS’s 8-Core XU208 USB Processor is dedicated for the USB DAC function.



I would like to thank IKKO Audio for providing me the Heimdallr ITB03 sample for review purposes. I am not affiliated with IKKO Audio beyond this review and these words reflect my true and unaltered opinions about the product.



Price & Availability:

The actual price of the IKKO Heimdallr ITB03 is 149.00 US$. More information’s can be found under the link below;




Package & Accessories:

The IKKO Heimdallr ITB03 came inside a rectangular box in black color that sports the illustration and some product related brandings on the top.


Inside the box of the IKKO Heimdaller ITB03 are the following items/accessories;

  • 1 x IKKO Heimdallr ITB03 Portable BT & USB DAC/Amplifier
  • 1 x USB Type-C to USB A adapter
  • 1 x USB Type-C to USB Type-C low profile cable
  • 1 x USB Type-C to Lightning low profile cable
  • 1 x Some Print Materials





Design & Build Quality:

The IKKO Heimdallr ITB03 is a Bluetooth & USB DAC/Amplifier that supports a wide variety of Wireless (LDAC, aptX, aptX-HD) and Wired (PCM, DSD) Lossless Audio Codecs packed in to an Ultra-Portable device, which shows a combination of glass and metal elements, the final result is a clean, robust and elegant looking device.

The Heimdallr ITB03 is an ultra-portable device with a solid look and feel when hold in your hands that shows a very good build quality. It has dimensions of about 70mm (L) *40mm (W) * 10mm (T) and weights approx. 72grams.

The deice features a metal frame and a glass surface that is located on both the top and rear surface with rounded edges, which offers a very good grip when hold in your hands.

On the top of the device is the IKKO brand logo and a small OLED screen with a resolution of 64×128 pixels that gives you lots of information’s like Connection Method, Battery Status, Decoding Rate, Volume, Lyrics, Audio Mode and Small Graphical EQ Animation on the main menu. I really like that the display shows you the name of the song that is played by the device, which is available in BT DAC/Amplifier mode. Even the Title of YouTube Songs and Videos is displayed, which is a nice feature.

The right surface of the Heimdallr ITB03 is equipped with 4 multifunctional physical buttons and a small hole where you can reset the device.

The Volume Up and Volume Down buttons can be used to navigate in the selected menus.

The Play/Pause button is a Multifunctional Key in order to switch between multiple sub-menus such like Gain (Low / High), Dimmer (1 – 6), Chare Mode, Filters (1 – 4), Car Mode and Sound Modes (Music, Movie, Game, HiFi).

The Power button is another multi-function key that will give you the access in to the sub-menus, which also acts as display on/off and button.

The left surface of the IKKO Heimdallr ITB03 sports a second opening dedicated for the build-in microphone for voice calls and voice commands when connected to a phone or tablet.

On the top of the IKKO Heimdallr ITB03 are the 3.5mm Single Ended, 4.4mm Balanced (TRRRS) analog outputs. The 3.5mm output serves also as Optical output interface, which is a great feature.

At the bottom of the device is the USB Type-C port that works for charging and digital sound input purposes.

The rear surface of the Heimdallr ITB03 sports the Hi-Res Audio logo some technical detail & industrial certifications.

Here is also the NFC logo and antenna for quick paring with your Bluetooth source, which is a nice addition.



Technical Specifications:

  • Model                         : Heimdallr ITB03
  • DAC Chip                   : 2x Asahi Kasei AK4377
  • USB Processor           : XMOS 8-core XU208
  • Sampling Rates          : PCM 32bit/384kHz USB / 32bit/96kHz Optical / Native DSD128
  • Headphone Amplifier : RT6863
  • Output Ports               : 3.5mm Single Ended (Analog & Optical) & 4.4mm Balanced (Analog)
  • Bluetooth Chip            : Qualcomm QCC5125
  • Bluetooth Version       : 5.0
  • Bluetooth Codec’s      : LDAC, APTX HD, AptX LL, AAC and SBC
  • Operating Distance    : approx. 10 Meters
  • Output Power             : 3.5mm SE 32mW @ 32Ω / 4.4mm BAL 125mW @ 32Ω
  • SNR                            : 118dB both Single Ended & Balanced
  • THD                            : -110dB
  • Battery Size                : 650mAh
  • Battery Life                 : Up to 8 hours (SE, Single DAC)
  • Charging Time            : approx.1.5 hours
  • Dimensions                 : approx. 70mm x 40mm x 10mm
  • Weight                        : 72 grams




Hardware & Connectivity:

The IKKO Heimdallr ITB03 is an Ultra-Portable and very capable All-in One Bluetooth & USB DAC/Amplifier solution that is compatible with a wide variety of platforms including Android, iOS, MAC OS, Windows 10/11, Nintendo Switch, Sony PlayStation 5 and Microsoft XBOX devices. The Car mode is another feature that makes Heimdallr ITB03 also compatible for the use in your Car as an AUX source.

A. DAC (Digital to Analog Converter):

The IKKO Heimdallr ITB03 is equipped with 2x Asahi Kasei AK4377 DAC’s (Digital to Analog Converter) that supports PCM up to 32bit/384Khz and Native DSD up to DSD128. It offers a SNR (Signal to Noise Ratio) of about 118dB and THD (Total Harmonic Distortion) of -110dB.

The Asahi Kasei AK4377 DAC Chip offers 4 different Digital Filters that are listed below;

  • Fillter1 Steep drop: sound dry and crisp.
  • Fillter2 Steep drop after a short delay: mellow sound, suitable for pop music.
  • Fillter3 Steep drop: Natural and mellow low end, good for slow music.
  • Fillter4 Slow drop after a short delay: high sound reproduction, suitable for classical music.


B. Bluetooth & NFC Connectivity:

The IKKO Heimdallr ITB03 is equipped with Qualcomm’s latest and most advanced QCC5125 Bluetooth chip that supports the Bluetooth V5.0 protocol. The BT SoC of the device supports most of the advanced Hi-RES wireless codec’s including LDAC, LHDC, aptX HD, aptX LL, aptX, AAC and SBC.

The Heimdallr ITB03 offers a rock solid Bluetooth operating distance that works flawlessly up to 9 – 10 meters. The device has also a decent performance while watching to videos and movies on YouTube, Netflix, Disney+, Amazon Prime, which doesn’t have shown any remarkable lip-sync latency issues when paired to my Samsung Galaxy TAB S8 Ultra and Samsung Galaxy S22 Ultra, thanks to the support of the latest aptX-LL and LDAC low latency codec’s.

The pairing of the IKKO Heimdallr ITB03 with sources like Android/iOS phones, tablets, etc. are quite easy. You have also the option to pair it to other compatible devices with just a simple tap by using the NFC wireless short-range communication protocol, entirely avoiding the cumbersome traditional pairing process.


C. Outputs / Amplification / Drivability / Hissing:

The IKKO Heimdllr ITB03 comes with a balanced audio architecture, which means that each channel is driven separately from the other with its own DAC and Amplifier. The device is equipped with both 3.5mm Single Ended and 4.4mm Balanced analog interfaces that do offers a pretty powerful and clean output.

The Heimdallr ITB03 comes with 1x RT6863 independent amplifier. That RT6863 offers an output power of 32mW @ 32ohm over the 3.5mm Single Ended port and up to 125mW @32 Ohm over the 4.4mm Balanced output. The device has two gain options that are Low & High gain, which can be selected over the sub-menu. Both the 3.5mm Single Ended & 4.4mm Balanced outputs do show a pretty clean output with very low amount of hissing.


D. XMOS XUF 208 Chip & USB DAC function:

The IKKO Heimdallr ITB03 is a pretty capable device that utilizes an 8-Core XMOS XUF208 chip that gives it the ability to work as USB DAC/Amplifier, which will support sampling rates up to 32 bit/384kHz and Native up to DSD128. The USB DAC functionality can be activated under the HiFi Audio Mode option and supports USB UAC 2.0.


E. Microphone:

The IKKO Heimdallr ITB03 is equipped with a built-in microphone with supports Qualcomm’s cVc 8.0 noise cancellation technology in order to suppresses background noises. The microphone offers an average performance in terms of voice transfer that I have tested paired with my Samsung Galaxy S22 Ultra.


F. Battery Life:

The IKKO Heimdallr ITB03 is equipped with a built-in battery that has a capacity of approx. 650mAh, which takes about 1.5 hours to be fully charged. The 3.5mm Single Ended output offers around 7.5 – 8 Hours, while the more powerful 4.4mm Balanced out shows up to 6 hours of battery life at Low Gain and Volume 20 out of 60. The overall battery performance is pretty good for such a small device.




Equipment’s used for this review:

  • DAC/Amplifier’s        : IKKO Heimdallr ITB03, Shanling UP4 2022
  • IEM’s/Headphones   : IKKO Opal 2, FiiO FD7, iBasso IT07, SIVGA Oriole
  • Sources                     : Samsung Galaxy S22 Ultra & TAB S8 Ultra, Asus TUF FX505DU




Albums & tracks used for this review:

  • Adele – My Little Love (Spotify)
  • Randy Crawford – On Day I Will Fly Away (Flac 16bit/44.1kHz)
  • Hayley Westenra – Odyssey Album (Dezzer HiFi)
  • Dionne Warwick – Walk On By (Flac 16bit/44.1kHz)
  • Sarah McLachlan – Angel (Flac 24bit/48kHz)
  • Sertap Erener – Aşk (Flac 16bit/44.1kHz)
  • Edith Piaf – Non Je Ne Regrette Rien (Flac 16bit/44.1kHz)
  • Diana Krall – So Wonderful (DSF)
  • Aretha Franklin – I Say A Little Payer (Flac 24bit/96kHz)
  • Sonya Yoncheva – (Giuseppe Verdi) II Trovatore, ActI (Flac 24bit/96kHz)
  • Dave Gahan (Depeche Mode) – Free Love (Flac 24bit/96kHz)
  • George Michael – Don’t Let the Sun Go Down on Me (Flac 24bit/192kHz)
  • David Bowie – Heroes (Flac 24bit/192kHz)
  • Elton John – Rocket Man ((Flac 24bit/96kHz)
  • Barry White – Just The Way You Are (Flac 24bit/48kHz)
  • Isaac Hayes – Walk On By (Flac 16bit/44.1kHz)
  • Sting – Englishman in New York – (Flac 24bit/48kHz)
  • Eric Clapton – Wonderful Tonight (Flac 24bit/96kHz)
  • B. King – Riding With The King (Tidal Hi-Fi)
  • Dave Gahan – Kingdom (Tidal Hi-Fi)
  • U2 – Sunday Bloody Sunday (Flac 16bit/44.1kHz)
  • Bro Safari, UFO! – Drama (Deezer HiFi)
  • Armin Van Buuren – Vini Vici (Flac 16bit/44.1kHz)
  • Daft Punk (feat. Panda Bear) – Doin’ it Right (Flac 24bit/96kHz)
  • Jo Blankenburg – Meraki (Spotify)
  • Lorde – Royals (Flac 24bit/48kHz)
  • Massive Attack – Angel (Flac 24bit/48kHz)
  • Toutant – Rebirth (Deezer HiFi)
  • Gogo Penguin – Raven (Flac 24bit/192kHz)
  • Gogo Penguin – Murmuration (Flac 24bit/192kHz)
  • Photek – The Hidden Camera (Flac 24bit/96kHz)
  • Portishead – It Could Be Sweet (Spotify)
  • Max Richter – On the Nature of Daylight (Flac 24bit/96kHz)
  • Charly Antolini – Duwadjuwandadu (Flac 24bit/192kHz)
  • Abel Korzeniowski – Dance For Me Wallis (Deezer HiFi)
  • Ferit Odman – Look, Stop & Listen (Flac 24bit/192kHz)
  • Chopin – Nocturn No. 20 In C-Sharp Minor (Flac 16bit/44.1kHz)
  • Fazıl Say – Nazım Oratoryosu (Live) (Flac 16bit/44.1kHz)
  • Vivaldi – Le QuarttroStagioni “The Four Season” (Deezer HiFi)
  • Otto Liebert & Luna Negra – The River (Flac 24bit/192kHz)
  • Lunatic Soul – The Passage (Flac 16bit/44.1kHz)
  • Deftones – My Own Summer (Shove it) (Flac 16bit/44.1kHz)
  • Metallica – Sad but True (Flac 24bit/96kHz)
  • Metallica – Master of Puppets (Flac 24bit/96kHz)
  • Opeth – Windowpane (Flac 16bit/44.1kHz)
  • Megadeth – Sweating Bullets (Tidal Hi-Fi)
  • Muse – Hysteria (Flac 16bit/44.1kHz)
  • Rush – Leave That Thing Alone (Flac 16bit/44.1kHz)
  • Slayer – Angel of Death (Spotify)
  • Liquid Tension Experiment 2 – Acid Rain (Spotify)
  • Yosi Horikawa – Bubbles (Spotify)





The Sound:

The Hidizs DH80 is a DAC/Amplifier with a fairly dynamic sound character which shows a mild amount of coloration. The lower frequency area shows a nice sense of body and fullness, the midrange is pretty natural and detailed, while the treble range is successful in terms of extension, clarity and control.

This review has been written after a burn-in period of about 50 hours. My sound experience below are mainly based on impressions with In-Ear Monitors like the IKKO OH2, FiiO FD7, iBasso IT07 and SIVGA Oriole.




The IKKO Heimdallr ITB03 has a pretty natural and linear bass response that shows a low amount of coloration that adds the general presentation a nice sense of musicality. The subbass region is reproduced with a decent grade of depth and extension when I listen to it with IEM’s like the FiiO FD7 and iBasso IT07. The 4.4mm balanced output is able to deliver a clean, controlled and deep subbass experience, when I listen to tracks such like Daft Punk’s “Doin’ it Right” or Lorde’s “Royals”.

The Heimdallr ITB03 has a pretty natural midbass response that offers a good grade of impact and control, without to lose the sense of clarity and resolution of the song I have listen to, while the coloration that is added is quite minimal. Songs with complex bass passages such like Gogo Penguin’s “Murmuration” or Charly Antolini’s “Duwadjuwandadu” are reproduced in a pretty clean and controlled manner, without to have any remarkable negative conditions such like a midbass hump or muddiness. The sense of layering and separation while listen to instruments such like a kick and snare drums is excellent, especially when paired with IEM’s like the FiiO FD7 and iBasso IT07.



The IKKO Heimdallr ITB03 shows a fairly natural, transparent and detailed midrange character, with a touch of warmth that adds the overall presentation a nice sense of musicality when I listen to instruments or to vocals that was pretty audible, especially when paired with IEM’s like the IKKO OH2 or FiiO FD7. The general midrange presentation of the Heimdallr ITB03 can be described as pretty balanced, lively and airy. The lower midrange is reproduced with a an efficient grade of body and depth that was pretty audible while listen to male vocals like Dave Gahan, David Bowie or Barry White or to strings such like a viola or acoustic guitar.

The upper midrange is shown with a decent level of clarity and resolution without to have negative conditions such like sibilance or over brightness. Instruments from guitars to flutes, from pianos to cellos are represented with an efficient amount of clarity and resolution, while or female vocals like Adel, Sertap Erener or Edith Piaf did sound pretty natural, lively and emotional. The resolution of instruments and human voices is pretty exciting for an ultra-portable BT/USB DAC/Amplifier at this price level.



The IKKO Heimdallr ITB30 has a pretty balanced and natural character treble presentation that is shown with a decent sense of presence and brilliance. The coloration in this area is quite minimal, which shows only a tad of additional warmth and note weight. The transitions from the upper midrange towards the lower treble region are in general fairly controlled, especially in moments when instruments or soprano vocals are shown with higher level of distortion.

The lower treble region of the Heimdaller ITB03 shows a decent grade of clarity and definition, while the extension and separation of instruments such like violins and pianos is on a successful for a portable DAC/Amplifier at this price range. The upper treble area is shown with an efficient amount of airiness and sparkle. Percussions such like kick drums and hi-hats are reproduced with a sufficient sense of presence and airiness, while violins and toms do have just the right level of attack and extension when I do listen to it with IEM’s like the IKKO OH2. Crash and ride cymbals on the other hand do have a tad of warmth that helps do avoid negative conditions such like over sharpness.


Soundstage & Imaging:

The IKKO Heimdallr ITB03 shows a fairly spacious and airy soundstage atmosphere that meets my expectations from a product at this price range. Instruments and vocals do have enough headroom for a relative accurate placement and separation. The soundstage is reproduced with an efficient grade of depth and wideness, while the height of the stage is on a moderate level.




IKKO Heimdallr ITB03 versus Shanling UP4 2022 Edition:

The UP4 2022 Edition is Shanling’s latest Ultra-Portable BT & USB DAC/Amplifier, which is a direct rival of the IKKO Heimdallr ITB03 that I would like to compare for you.

The Shanling UP4 2022 shows a tad warmer tonality compared to the IKKO Heimdallr ITB03 that sounds a bit more neutral and balanced. The subbass region of both devices shows a pretty similar level of depth and extension, while the Heimdallr ITB03 offers a bit more clarity and resolution in this area when I do listen to kick-drums and bass guitars. The IKKO Heimdallr ITB03 has the slightly edge when it comes to the control and separation in the midbass area that was audible in songs with complex bass passages such like songs like Gogo Penguin’s Raven.

Both the Heimdallr ITB03 and the UP4 2022 Edition do offer a decent midrange performance, especially with respect for their price. The Shanling UP4 2022 sounds a tad warmer and fuller, due to a slightly coloration in the lower midrange area. The IKKO Heimdallr ITB03 on the other hand offers in general a more natural and spacious midrange presentation, with better sense of clarity and micro detail retrieval. Both sources do offer a pretty controlled upper midrange presentation, while the Heimdallr ITB03 sounds slightly more accurate and natural when I listen to female voices and instruments like violins and pianos.

The treble range of both the IKKO Heimdallr ITB03 and the Shanling UP4 2022 Edition sounds pretty energetic & pronounced, without to get out of control. The Heimdallr ITB03 has the slightly edge when it comes to the treble extension, while both are successful in terms of resolution.

Both devices do offer a decent performance in terms of separation and placement of instruments and vocals. However, the IKKO Heimdallr ITB03 shows a slightly higher sense of airiness and wideness, while the depth of the stage is relative similar.



IKKO is an innovative company that is also known with its attention to the smallest details of all released products and the Heimdallr ITB03 is not an exception. The Heimdallr ITB03 Bluetooth & USB DAC/Amplifier impressed me in with its solid overall sound performance, build quality and all the well implemented hardware features, which are packed in to this ultra-portable devices with a very esthetic design that has a quite reasonable price. All in all, highly recommended!



Pros & Cons:

  • + Excellent Overall Sound Performance for such a small All-in One Solution
  • + Solid Build Quality
  • + Esthetic Design
  • + 3.5mm SE & 4.4mm Balanced Outputs
  • + Only Device in its Segment that is equipped with an Optical Output
  • + Clean & Hiss-free output
  • + Value for Your Money


  • – The glass surface looks beautiful but is also a fingerprint magnet
  • – No Protective Case
  • – No Back-Clip


Thank you for the Read!


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