Good to hear the HD 58X and HE 4XX are good compliments. I need to reintroduce both back into my collection as the HE 4XX I had previously still stands as my Go to 1st Planar recommendation.
Though Iād like to compare the HD 58X with stuff like the K702 and DT 880 before it earns itās place in the sub $200 recommendation zone
Non the less, I had a chance to review the QP2R a while back and found myself quite enamored with it!
Without further ado letās dive into the Questyle QP2R!

Packing is modest and it does the job, also a thank you to Todd The Vinyl Junkie for setting up this QP2R Tour!
So some background on the Questyle Dap, unlike traditional circuits, Questyle opt for Current Mode amplification. In short if my understanding is correct, the Voltage levels are fixed and the current is what amplifies. Unlike a traditional amp design in which the Current is Fixed and the Voltage is whatās amplified, either way it operates in a pure Class A ācurrent mode.ā The Questyle website has more information for those inclined!
Another unique feature of the amp is the Bias Control, again when the ampās under a heavy load setting the Class A Current Mode Bias to High helps to eliminate high frequency harmonic distortion. An most of you know that excessive distortion translates to noise, so any time we can reduce added distortion there are audible benefits assuming the load is āheavyā enough. Either way for my listening purposes I kept it set to High always. As a result battery life has been a little less than whatās quoted but nothing too unmanageable.
Seeing as this is my first foray into Top of the Line Digital Audio Players I tested this one againāst quite a few of my own home systems and headphones!
How ever I only listened to the QP2R with itās 3.5mm Single End and 2.5mm Balanced Out. I didnāt test it as a USB Driver Dac Amp nor did I use the Line Out Settingsā¦ but I think you need the HiFi Hub to get that featureā¦ which Iām not a fan of. With the HiFi Hub the total cost of the unit creeps upwards of $1700, and while price isnāt my concerns itās the very stationary and cumbersome nature of the Hub and the price increase I donāt like. I got portable for well portability! Having a built in LineOut without any additional bulk means a lot to ME and those who will be using this as both an analog and digital source. Non the less though, at itās $1300 price point functioning purely as a standalone Digital Audio Player I do have to admit itās performance is stellar! Well worth the asking price.

I found that with my HD 800 and the 2.5mm balanced output the QP2R had;
- Exceptional naturalness in the mid range
- Listening to Epicaās The Divine Conspiracy I heard details in Simone and her husbands voice Iād not heard before!
- Exceptionally low noise
- Or it presented a very black sound
- Silence was inky and this lack of noise again lead to exceptional resolve
- Textured but smooth response
- The overall lack of distortion really yields a smoother well resolved sound in both the mid range and upper end
- No lack of detail or extension in the mids and up top, rather slightly more detail than I was expecting with no added harshness or grain
- Fatigue free listening
- Fairly Soft Low End
- Sufficient definition and texture, but slightly lacking in solidity and power
- Kick drums lacked that āKICKā and an aggressive bass guitar riff was a little smeared
- Cellos and Painos had beautiful timbre, tone and texture but again electrical instruments and percussion were slightly soft
- Lack of Headroom
- With my most dynamic tracks I was only able to get an average of 83 dBs about 4 less than what I prefer to listen to [87 dBs averaged]

I also ran the Audeze MX 4 balanced out with an OCC Copper Cable from the 2.5mm on the QP2R, I found it to be;
- Clean, Clear but could extend a little deeper
- Good power and slam with exceptional texture!
- Here is where I found the High Bias to make a noticeable differance
- Electric Bass Guitar riffs were dynamic, punchy with good bitw
- Kick drums had IMPACT
- An larger drums like the Timpani had a powerful heavy but slightly hollow sound as I expect them to
- Though some of the deepest notes were slightly withdrawn
- Energetic Up Top
- Had just enough clarity and presance
- Percussion was snappy and never harsh
- Natural Mid Range
- Again beautiful smooth but textured mid range
- Harmonic content resolves nicely, beautiful release on guitars, vocals and stringed wood body instruments
- Vocals have a nice little bit of added sweetness to them
- Intimate still but spacious
- Precision is acceptable but cohesiveness and clarity in resolving complexly layered content is evident
With some a little more efficient I felt the QP2R really shined, itās natural and smooth but still dynamic and detailed presentation came through better with the Gain set to medium or lower and with more efficient current hungry planars than more voltage hungry dynamics like the HD 800 which often couldnāt quite get to reference listening levels nor maintain a solid low end.
Ultimately though, with two different loads I deemed the QP2R to always present;
- An exceptionally low noise floor
- Inky black background
- So much so that there were some details presented to me by the QP2R that Iād not heard before out of my own home system!
- An upon level matching I did in-fact identify such details in my home system but the slight addition of added noise made said details fall just shy of my notice in previous listening sessions
- Exceptionally low distortion
- Allowing for incredible resolve with no added fatigue or harshness
- Both Micro Detail and transients were exceptionally vivid
- With no lack of dynamics
- Natural Timbre and tonality
- Again both the fundamental and harmonic content of instruments and vocalists alike were always crystal clear
- Optimized for more Efficient Loads
- Often running out of steam with more voltage hungry loads
- Often losing some extension on the very deepest reaches with quieter tracks
So simply put, Questyleās newest reference digital audio player does everything weād want it to! In my case it replicated and sometimes exceeded the quality of my own home system! Itās only faults lie in a slight lack of power overall and definition down low.
Switching to my home system some of whatās gained or clearer in the mid range and up becomes some what less vivid but thereās added vividness and clarity down low. So again, Iām impressed given how small the unit is that it keeps paces with my current reference system.
Non the less, letās get into more specifics on how the QP2R compared to my other systems! Both portable and desktop.
Starting with my my Singled Ended and Mid Range Portables

With my Modded ES10 the QP2R;
- Simply out classed the Singled Ended Shanling M3S & Aune B1S system completely with itās own 3.5mm Single Ended output
- Simply out classed my Geek Out V2+ with itās own 2.5mm Balanced Output
Which I was a little shocked by, as my Geek Out v2+ gave the Hugo 2 [USB] a run for itās money, in this comparison the QP2R showed no mercy and clearly beat the Geek Out V2+
How ever with my Single Ended HM901/HeadAmp Pico Power system I found that;
- The HM901/HeadAmp Pico Power System was overall better
- Had a more linear response
- Powerful and taut low bass
- Very Clean slightly drier mid range
- Better Top end extension
- Where as the QP2R fell a bit behind
- It wasnāt any quiter or blacker
- Had a slight forwardness in the mid range thatās apparent with this super sensitive OnEar
- Had a slight over-emphasize on ambient noise
- Not so much mechanical noises but stuff like floor board creaking
- In a sense these details were more vivid but overly so
- Just fell short of drawing me into the music
- Technically it wasnāt up to par with the HM901/PicoPower System
- An the Timbre was as inviting as the with HM901/PicoPower System
So that kinda threw me for a loop! As it would seem the QP2R handles what I would consider moderately difficult loads best. As with the sensitive ES10 and the Difficult to Drice LCD 2 PreFazor it didnāt wow me like it did with the MX4 and HD 800.

Speaking of the Pre Fazor LCD 2, output from the QP2R
- Again out classes the Geek Out v2+ in terms of technicalities
- However the tonality and timbre were noticeable drier and kinda shouty?!
- So Your preference tonally may dictate how much you appreciate the improved technicalities
However compared to my HM901/PB2 System the QP2R falls a little short every where but the bass ironicaly;
- Tonality is noticeable drier
- An some how less natural than the Hm901/PB2 System
- Background noise is reduced
- So micro detail is sometimes better but odd tonality often skews some transients
- Ambient noise is exaggerated
- Again the normally the LCD 2 is quite dark, but for some odd reasons with the QP2R itās noticeably brighter
- Macro Dynamics are also some what exaggerated at the expense of micro dynamics
- Bass is quite textured however
- Iām assuming itās because of the slightly more difficult load requirements of the current hungry Pre Fazor,
All in all Iām finding that I prefer my PreFazor LCD 2 on both of my ESS Sabre portables that have the high Frequency roll off digital filters.
So all in all I feel that with more modern offerings the QP2R would do well, with loads that are more standard. As the ES 10 is hyper efficient and the LCD 2 PreFazor on the opposite end of the spectrum. So cans like the LCD 2F would pair very well with the QP2R as would things like the DT 880/1990 and Hifiman HE 560. Though letās move upwards to other TOTL systems in my home!

Staring with the HD 800 vs the HM901 & iBasso PB2 System
Before we go further you should know my iBasso PB2 is modified with;
- LME 49990 High Performance OpAmps
- High Current Buffers
- Dedicated Portable Power Supply Unit
- The internal battery has been removed and all power is kept at a stable & Constant 16V
Non the less, compared to this portable system with the HD 800 I found the;
- Bass
- Tauter and more defined with HM901/PB2 System
- Namely big timpani drums maintained a great sense of impact and weight, while balancing the hollow resonant trails that follow each strike
- Kick Drums hit harder, faster and had a cleaner envelope overall
- Mid Range
- Quite dry on the HM901/PB2 System
- At times this was an advantage especially with Epica
- Where beautifully warm wood bodied classical instruments are over laid with heavily distorted guitars
- Though at times it was a disadvantage
- Such as with Rebecca Pigeonās Spanish Harlem where the timbre of each instrument was slightly drier than reality
- Wetter but no less defined with the Q2PR
- With Heavy Metal the added wetness some times detracted from the aggressiveness of the track as a whole
- But with softer acoustic pieces the presentation was more natural with no ādrynessā
- Top End
- Each unit had itās own advantages and disadvantageous
- The HM901/PB2 system had clearly better top end extension which resulted in a better sense of pace & rhythm and time especially in percussion but it could also be fatiguing depending on the mastering
- The QP2R was smoother up top, so while it didnāt always have that vibrant sense of presence, rhythm and time it was never fatiguing
- Resolve/Imaging
- Volume matched each had no clear advantage over the other, how ever the increased headroom of the PB2 System allowed for āreferenceā listening levels at which slightly more resolve/imaging precision is possible due to a more even tonal perception
Now compared to my Reference SET Tube Amp the QP2R;
- Only had the advantage of a blacker background
- Some detail in the mid range and up was more apparent but there was a lack of control and extension on the lowest registers of the audible spectrum
- More or less replicated and matched the cohesiveness and overall precision in imaging
- More or less replicated or matched my Desktop Amps sense of presence and tactility
- Except in the lows
- My Desktop Amp consistently presented a more detailed more controlled low end
- Struggled to provide sufficient headroom
- Again with tracks that had exceptional dynamic range the QP2R was not able to bring these tracks up to at least 87 dBs on average
But overall with my HD 800 I can say for the vast majority of my collection the QP2R made for an excellent single box solution for some of you itās added simplicity and blacker background may be preferential over having a bulkier portable system with slightly more noise but sufficient head room and more controlled lows.
In either case Questyle certainly designed this product to very exceptionally match a desktop system on the go!

Moving to the MX4, with the HM901/PB2 System I noticed;
- Bass
- Tighter more and more controlled over all
- So big drums had more power
- Kick drums had more impact
- An large stringed instruments had a slightly more resolved or more audible fret action
- Mids
- Mid-range quality on each was fairly similar
- The QP2R was a smidge wetter and more natural so with a drier master or set of instruments it sounded more Natural
- Where as the HM901/PB2 System was drier so with a wetter master, or a set of instruments with a lot of harmonic content THIS system sounded more natural
- Highs
- With the QP2R system the MX4 did lose some vibrancy up top
- Where as the HM901/PB2 System was no less smooth but more vibrant
- I feel this has to do with the rougher presentation of the HM901 System combined with itās own HF Roll Off Filter allowing the texture of slight over emphasis to be present without the fatigue
- Resolve/Imaging
- The QP2R did take a slight edge forward in overall resolve because of itās blacker output
- However the more defined low end with the HM901/PB2 System did help to retain better precision in imaging
Now comparing the QP2R to my own Reference Hybrid Tube Amp
- Bass
- Again better power and extension
- Mids
- Now this is where things get interesting as;
- The QP2R is equally natural but presents a slightly clearer more defined envelope
- Allowing for the texture of stringed instruments
- The unique vibrato of a vocalists
- The unique harmonic decay/release of guitars
- An other micro detail present in the mid range was a bit more resolved
- My Project Ember II with a Classic Grade Psvanne CBT 181-T Mk2 was;
- Fuller but not as detailedā¦ period
- Highs
- Again the QP2R was;
- Clearer with a sharper attack
- Where as the Ember II was;
- A little smoother without as much emphasis on the leading edge
- Resolve/Imaging
- Now dynamics are were the QP2R falls slightly behind the Ember II as;
- The Ember II more clearly resolved micro and macro dynamics
- An in many cases the Ember II was able to very realistically build to a crescendo
- Where as the QP2R was;
- Sharper but a tad over enthusiastic at times
- Struggles with an accurate presentation of Pace, Rhythm and Time
- Failed to draw me into any passage of music that gradually builds tension through changes in volume
- However overall detail and precision in imaging was fairly similar between each
- Again the QP2R has a blacker background
- But doesnāt seem to respond as quickly to the demands of busier passages of music
- Where as the Ember II is a bit nosier
- but handles changes in amplification needs more linearly, how ever add noise kinda nullifies some of the advantageous it has here

All in all Iām quite impressed with the QP2R, while I found itās lacking in some digital convinces as a purely analog digital audio player itās excellent! Seeing as I personally prefer my DAPs run purely offline and exclusively in the analog domain I feel that the QP2R is totally deserving of itās flagship status! Iāve always been a dedicated DAP & Line Out To Portable Amp guy but with the MX4 and Questyleās excellent on board current mode topology I could happily accept this as my end game reference portable!