Dethonray Prelude DTR1+ – yet another endgame

Controversial topic, isn’t it? The endgame should be limited to one… What we mean is not another product of the same category, but the perfect match for the first endgame that we insisted on some time ago – Dethonray Tender 1 planar IEMs. Here is the link to our Tender 1 review if you have missed that. Such IEMs are very demanding in terms of source quality and very power-hungry. We have tried it in pair with various DAPs and DACs, but the best synergy is achieved only with DTR1+ which we would describe a bit later in this review.

Furthermore, since DTR1+ is a highly anticipated reincarnation of DTR1 – first DAP by Anson Tse (Dethonray founder) released back in 2019, that turned out to be fresh approach and revelation sound wise for many – we would also focus on the differences in the performance of the new version of this honored product.

One more input from us (out own understanding): neither Dethonray Prelude DTR1, nor DTR1+ is a mass product with thoroughly calculated economy and profit or decisively added/cut functionality based on marketing intents. It is rather distinctive, much more closer to western high-end niche approach, where the emotional appeal combined with technical SQ put at the forefront while the secondary features like functionality are left out for less narrowly focused equipment. For us, such approach is perfectly acceptable since we consider DTR1+ as the ultimate source that is only about the sound quality for our offline thoroughly selected audio collection in desktop or mobile setup. Although, there are couple of minor drawbacks that we would also describe in this article.

DTR1+ specs:

• Type: HiRes audio player
• DAC: AK4490EQ
• Sample rates: up to 32bit/192KHz
• Audio formats: WAV, FLAC, WMA, MP3, APE (Normal, High, Fast), AAC, ALAC, AIFF, DFF/DSF, OGG
• Frequency response range: 20Hz ~ 20kHz
• SNR: 117dB
• THD: 0.008%
• Max. power output: L: 6Vrms + R: 6Vrms (16Ω) | (1280mW@32Ohms)
• OS: Linux + Ocelot GUI
• Memory: MicroSD (exFAT), up to 1TB, handles 160,000 songs
• Audio outputs: 3.5mm Line-out + 3.5mm headphones
• Connectivity: Micro-HDMI (charging port)
• Battery: 2cell, LiON, ±8.5V PSU, life 8 hours
• Dimensions HxWxD: 100x57x18.6mm
• Color: Black
• Weight: 160g

Changes:

• Power output has been increased
• Redesigned the LPF circuit:
  • Using the top chips improves the resolution sharply.
  • Makes vocals a little more laid back for classical music and new recordings.
  • Enhanced the treble extension, the timbre sounds more lively.
• Redesigned gain and volume audio subsystem:
  • update the gain control to support different IEMs, earbuds, headphones.
  • subdivided the volume range to make the sound more accurate and natural.
  • Added separate R|L channel volume control (0.5dB steps)
• Added the index and classification function for artists.
• Added L/R channel volume compensation.
• Introduced new charging unit (Micro-HDMI -> power adaptor -> USB type C)
  • now any USB – USB type C cable can be used with the power unit
• Button redesign

Main features of the HW/SW part:

• Separate power for decoding and amplifying: DTR1+ adapts dual high-density battery customized power system, designed for High-Fidelity while ensuring separation of digital and analog power to eliminate circuit noise from the source, alike an enhanced DAP + Amplifier system but with a minimal path and hard soldered joints with no compromises. The ±8.5V PSU remarkably improves efficiency of clean power supplied to the system, with noticeable qualities in transparency and background noise control without the need to excessively damping the output.
• EMI shielding: with the precision machining on aviation grade, light-weight aluminum alloy, DTR1 is shielded from EMI disturbance for a cleaner background during play. Precise structural designs with high reliability parts also a patented user interface are combined in pursuit of perfection in sound and optimization of both hardware and software within the design.
• Custom LinuxOS and Ocelot GUI: DTR1+ runs on a deeply-customized Linux OS audio sub-system which utilize a OSS sub-system 30% higher in efficiency than the ALSA audio sub-system. The customized and optimized decode engine ”Nature” synergize effectively with the Linux OS, decodes in optimal condition and reduces transmission delay. Patented ultra light weight GUI system ”Ocelot”, Customized GAI (Graphics Abstract Layer), GDI (Graphic Device Interface), IAL (Input Abstract Layer), SCM (System Control Module), Audio files indexing system – promises minimal MMI, high speed navigation and supporting up to indexing 160000 songs.

Dethonray Prelude DTR1+ is available at the official Amazon store: LINK

Packaging and design:

Prelude DTR1+ comes in a regular, pretty large Dethonray black box where DAP rests on the upper layer of soft foam with special cut outs and charger is stored underneath. There is no USB – USB type C cable provided but you would also find short user manual and warranty card. We would suggest Anson to consider adding some kind of a case for such premium product.

The design has not changed much in comparison to its predecessor – clean, neat, old-school and functional. DTR shell is made of aluminum, except for the back cover. And if it was a glass panel in DTR1, now we have simple black plastics with shiny gold titles. Perhaps this is made for good: first, it won’t crack that easy and second – it would stand deformations better if the battery decides to inflate (hope that this would not occur in the nearest future. But eventually, all batteries die and large percentage do inflate). Another advantage over the previous version – now we have 2 screws at the back to get inside the shell and replace the battery, at least.

Top and left edges stayed blank, while the right still holds volume and power buttons together with SD card slot. Volume and power buttons were redesigned completely, all became larger and now it is much more simple for blind operation since the middle (Volume down) button made larger than the rest.

Bottom edge saved all of its elements – 3.5mm LineOUT, 3.5mm SE headphone OUT, micro-HDMI and Reset. But now both of 3.5mm ports have décor elements in a form of round golden outlines.

Facing side now looks much more organic with larger buttons, decorative lines and markings. Central (ENTER) button is now equipped with Dethonray logo.

Screen has not changed a bit, it seems that the LCD panel itself is exactly the same: 2.32″ TFT screen. The type of the screen and its resolution numbers are not provided among other device specs but my guess would be IPS with something like 640×480 pixels. At least, the viewing angles are ok and thin diagonal lines on the screen don’t produce a so called «ladder effect» common for low resolution screens in combination with larger physical size. Screen edges are ~4.5mm, partially hidden by black screen outlines that visually merges with the shell when the screen is off. Screen doesn’t have a touch sensor layer, thus all user interaction happens with the help of physical buttons. Which is great, we believe. Always preferred physical controls over touch screens for easy blind operations.

Despite that it is far from modern LCDs, DTR1 screen is doing its job quite well. Size is totally enough for convenient interaction with this certain UI, fonts and other graphics are large enough to stay visible. The main and the only concern is the maximum brightness level which is kind of low comparing to any other DAPs and is hardly enough to fight the direct sunlight or bright environment. Usable, but much better to stay in shade.

In overall, the design of the new DTR1 looks more organic and mature. Definitely better and more attractive than the first version of the DAP. Moreover, the operations now are more convenient, thanks to enlarged and reshaped buttons.

Device in use:

First of all – the new charger: separate small unit with status LED, micro-HDMI connector and USB type C port. Now, we can use any USB type C cable to connect to this charger from any 5V power adapter or USB port. Which means that DTR1 can now be charged from PC/laptops, etc but as far as we’ve understood – the function of mass storage has been eliminated. No possibility to get data transfer using the cable. Anyway, not a big deal considering low transfer speed of the previous version. It is always better to take the card out and write using card readers or laptop slots.

Charging unit acts as a step-up voltage regulator and indicates its stated with the status LED. Fast red flashes – no device connected, solid RED – charging. It heats up significantly during the use (~50C) while DTR1+ stays cold when switched on and left charging. Also a good sign for us – better to keep heating elements out of shell and away from the main circuits, battery and screen. Full charge takes around 2 hours and the battery last around 8 hours after that.

SW and GUI:

DTR1+ is running the same version of deeply customized Linux OS with Ocelot GUI as its predecessor. Anson has done a great job of bug fixing and further OS/interface customization during the first months after first version of DTR1 DAP release when active customers started to submit their suggestions and feedback. Since than, this SW combination stays very snappy and stable. No updates available so far, neither any bugs are found. We haven’t noticed any jitters or freezes. Boot time is fast but ends up with showing SD card availability warning and waiting until the track database would be rebuilt. This happens at each boot with no option to avoid it. Fortunately, it takes only ~3 seconds to rescan all files and start playing. Developers claim that this it the fastest process among all recent DAPs no matter the amount of files on SD card and the only payback is indexing upon each power cycle.

UI structure:

• Main player screen:
  • Playing now screen (current track + navigation through tracks)
    • Long press Select to go to Play options
      • Play options:
        • Return to folder
        • Favorites
        • Delete music
        • Play mode (repeat all, repeat one, shuffle, play one)
        • CUE
        • Play through folders
        • High|Low gain (headphones)
        • Line out gain
        • Filter
        • Idle shut down
        • Delete
  • All Songs (alphabetical order of all audio files)
  • Artists (alphabetical order of artists)
  • Favorites (list of tracks added to favorites)
  • Browse (browse through folders)
  • Settings
    • System information
    • Language (ENG|CHN)
    • Play Mode (repeat all, repeat one, play one, shuffle)
    • Backlight (up to 60 sec and always on)
    • Brightness (up to 100%)
    • Power key to main menu (ON|OFF)
    • CUE (ON|OFF)
    • Play through folders (ON|OFF)
    • Switch track when LCD off (ON|OFF)
    • High|Low GAIN (headphones: LOW|MIDDLE|HIGH|EXTRA HIGH)
    • Line out GAIN (LOW|MIDDLE|HIGH|EXTRA HIGH)
    • Filter (Sharp roll-off|slow roll-off|short delay sharp roll-off|short delay slow roll-off)
    • Channel balance
    • Idle shutdown (up to 30 mins and always ON)
    • Timing shutdown (up to 60 mins and always ON)
    • Database upgrade
    • Reset all settings

So, the main newly introduced function is separate 4-step GAIN for headphones and line out. In case of line out it is the only option to limit or increase the volume for active speakers or amp (if not enough or too much). As for headphones, we have found that 4-steps is a kind of overshoot since MIDDLE is already dark on the background for low impedance IEMs and EXTRA HIGH is suitable for anything above 32 Ohms depending of its type. For example, Tender 1 planar IEMs are only 28 Ohms but feel underpowered with any option rather than EXTRA HIGH. On the other hand, pure armature 32 Ohms are a way overpowered… Therefore, let’s say that 3 steps would be enough.

Each track is provided with bit/KHz information on playing now screen, long names are cut if don’t fit the screen width. Still no scrolling. Album art is present.

DTR1 heats up very little even while decoding 24bit/192KHz and playing with 50Ω full-sized overheads at High gain setting. The only time it heats up a bit more is while taking a charge and playing music simultaneously. Case reached about 34C at max which is absolutely no issue.

Sound quality:

Tested with: Dethonray Tender 1 planar, Oxygen single DD, HiBy Beans IEMs, Audio Technica ATH-M50, xDuoo MT-602 amp, etc

Getting back to synergy and endgame question: of course, our first and main intention was to find the best match for Dethonray Tender 1 planar magnetic IEMs. Those are perfect at all aspects, superior to any DD, hybrid or armature rivals by its even representation, rich timbre and perfect instrument separation. The only problem is that Tender 1 are very demanding in terms of power and quality of the source equipment. Moreover, since planar nature looses some resolution – we wanted to pair powerful and very resolving DAP with it. DTR1+ is the best candidate since it is similarly linear, gives out huge amount of details and able drive Tender 1 to full potential. Furthermore, as Anson told us – he has additionally tweaked DTR FW to match Tender 1 and to reach the best possible synergy. So, most of our impressions would be built upon DTR1+ and Tender 1 pair. We would also partially copy the text from DTR1 DAP review, highlighting the changes in the sound of its new version.

Lows:

Bass plays an important role in the sound presentation of DTR1+. It does a perfect job on highlighting bass contours with fast decay and transitions. Bass has a decent weight here, even a bit emphasized but not shadowing other ranges. Lows are perfectly exposed, have extra clarity but not standing out as it was with the predecessor. Extension and amount of textures are slightly limited in a favor of accuracy, speed and integrity of the perception. Such reproduction of lows is less regular but quite interesting and highly appealing. Midbass is perfect, neither too bright or too dark, natural, powerful, tight and engaging. Drums never get too harsh even in the tracks with some extra gain added to this part. In overall, DTR1+ lows sound more organic and integrated to the entire mix if to compare to DTR1.

Mids and vocals:

If you ever wanted a DAP with huge amount of details, clarity and resolution on voices and instruments in mid section — DTR1+ is here to capture your mind. The first try overwhelmed with the feel of extra resolution of keen mids even with the reference dynamic IEMs. Pairing it with BA extends this perception even further. Outstanding resolution and bears the clarity of each single sound which leads to reconsidering the knowledge of the most favorite tracks. And this is not a joke — most of the DAPs on my shelf are more or less similar, tending to the reference side with neutral or warm tonality and moderate amount of details for the sake of melodious presentation. DTR1+ acts completely different — it reveals maximum amount of details in a rampant impulse to convey emotions. It doesn’t mean thinner or colder sound any longer, nor it is prone to hisses – just the new experience with extra clarity and resolution. Absolutely impressed by the approach of DTR1+ towards mids, especially with neutral and mid-sensitive IEMs. Comparing to DTR1 – new version gained more body in mids and became slightly thicker which made the sound even more balanced, easy and linear on perception. Absolutely no screaming sounds, peaks or lisping, absolutely accurate and resolving.

Treble:

This is logical that if mids are impressing with exceptional resolution and clarity — treble would be even more capable of the same as the part of such perception on mids originate from the reproduction of treble. This is true — decent clarity, transparent and airy sound here. Treble is not overemphasized or piercing, it has the same weight with no perceptible accent, sounds extended, accurate and balanced to other ranges. Some lack of gentleness is compensated by huge amount of details and distinct exposition. Changes with DTR1 are subtle since the extension, resolution and control of this range was perfect with DTR1 and stays perfect with DTR1+.

Soundstage:

Another good outcome of excessive clarity and resolution is the extended depth of the perceived soundstage. Instrument separation and overall sound transparency is so good and the location of each instrument is so evident that the stage gets the necessary and pleasing depth of field. Although, width is not that impressive as the lows don’t spread out much to side but rather kept collected. No apparent changes with DTR1.

Sound in overall:

Dethonray Prelude DTR1+ sound can be described as highly detailed, perfectly balanced between the ranges, transparent and linear, with rich timbres and very calm performance. Instrument separation is decent which makes DTR1+ a best contender when it comes to HiRes tracks with lots of instruments and drive. Similarly to its appearance, the sound has matured – became slightly thicker, maintaining similarly high resolution but now delivered in a perfect monitor nature. All rough edges got proper treatment – now this DAP is totally transparent for any end gear.

The best experience is DTR1+ and Tender 1 performing together. This DAP provides enough details to compensate Tender 1 planar nature while Tender 1 is pushing instrument separation, timbre of mids and overall gentleness of the sound to maximum. This particular pair is what we were talking about when we said that we have grown up from rough listening on-the-go and want to focus on calm evening sessions and delicate sound. Interesting additional observation is that the only competition we have found for DTR1+ / Tender 1 pair is the combination of HiBy R5Pro + xDuoo MT-602 tube amp + Tanchjim Oxygen IEMs. Such combination lacks some resolution but the rich and delightful timbre is possible with the tube overtones of MT-602, delicacy of Oxygen IEMs and power of R5Pro. Almost the same budget, though… which is expected, actually.

Conclusion:

Never thought that the original Dethonray Prelude DTR1 would ever get beaten concerning its stellar audio performance. Lots of DAPs from other brands since 2019, more functional and modern, but DTR1 always stayed very distinct benchmark for clarity, resolution and monitor-like sound. But here comes its successor, with better design, new functions and what is the most important – polished, free of any rough edges, more thick and linear performance that also carries all nuances what we loved DTR1 for. Adding here the excellent synergy with recently introduced Tender 1 planar IEMs – and this bundle becomes very unique object of desire among high-end portable sources. The only function that we regret is the absence of USB DAC but the rest such as MQA or Bluetooth audio are from another world and for another segment. Dethonray Prelude DTR1+ is solely and completely occupies the niche of a DAP with highly detailed, powerful, analytical sound, totally transparent for any end gear.

Dethonray Prelude DTR1+ is available at the official Amazon store: LINK