Xduoo XD-05 Basic

Disclaimer:  The XD-05 Basic was provided by Xduoo for this review at my request.   I have owned the XD-05 for several years now and the Plus for about a year and think the XD-05 series is one of Xduoo’s best to date and one of the best portable DAC/Amps in the budget space.   The basic hearkens back to the original XD05 so I was interested in what had been updated since the original release.     Should you want more information, see Xduoo’s website or to purchase an XD-05 Basic, give Xtenik a try. 

 

Unboxing / Accessories:

Xduoo has a great graphics department and the packaging on the basic is much like that of the Plus.   The outer packing has the line drawing of X circuit logo on the front and sides and specs on the reverse.  Removing the outer packaging reveals a solid black box with the Xduoo name in gold near the top.    Lifting the cover of the box reveals the unit in a foam surround with all other accessories hidden in a box underneath it.  One bad thing, the foam surround that guards the unit has a solid bottom with no cut outs or indications that the other box even exists or how to access it.  If you lift the foam, the accessories box has cut-outs to lift it out of the main container.   The kit has two usb interconnects (micro to C, and C to C), a USB-C to USB-C cable for computer connection or charging, a USB-C to USB-A adapter for older computers,  a neoprene pad to place between phone and the XD-05+, extra screws, feet, and a 6.3 to 3.5mm jack adapter.   A fairly complete manual and a warranty card round out the package.

 

Build:

Those  familiar with any XD05 will recognize the form factor of the Basic.  Currently, the Basic is only available in the dark grey finish but may become available in silver at some future date.  The volume knob is now red anodized aluminum and makes the Basic immediately identifiable when compared to the Plus or the original.   The metal shells are interchangable between models but the faceplates are not as switch positions are different.    The front face plate is similar to the original with 6.3mm jack, input switch, bass switch, gain switch and volume control.   The rear faceplate now has 3.5mm Aux in/out, USB-C data port, a battery cut-off switch, USB-C charge port, and 3.5mm digital input (coax/optical).    Buttons on the Side, are Display, SRC, and filter (More on those later).   Build photos show the Plus and basic for comparison sake.

 

Internals:

Those familiar with the XD-05 will be most interested in what changed and the answers are a lot more apparent on the inside than on the exterior of the unit.  Starting from the inputs, the USB duties are now handled by the Xu208 which allows for PCM up to 32/384 and Native DSD256 support.   Optical and coaxial inputs are still limited to 24/192 if one can realistically call that a limit.   DAC duties are handled by the AKM4490EQ of the original model while amplification is handled by an Ne5532 dual op-amp in a socket that allows replacement.  Unlike the Plus, the basic only allows use of dual op-amps as it only has one socket.  Adapters to convert two singles to a double pinout do exist, but likely won’t fit with the case on.  Not all of the features of the DAC chip are usable as the input limits it below its 32/768 PCM maximum and  DSD 11.2 MHz max of the AKM4490EQ.    Clocking is handled by two oscillators at 22 and 24 Mhz respectively.

I did my listening with the stock op-amp (Ne5532) and then promptly swapped in a  Muses02  and later a single Burson V5i to see what impact they had on sound quality.

Features compared:

	Original	Plus	Basic
Size of Screen	0.91 Inch OLED	0.91 Inch OLED	0.91 Inch OLED
Volume Control	Yes	Yes	Yes
Output ( Single end)	6.5mm	6.5mm	6.5mm
Output Port ( Balanced)	No	No	No
Input Port ( USB )	USB A	Type C	Type C
Input Port (Coaxial)	3.5mm	3.5mm	3.5mm
Input Port (Optical)	3.5mm	3.5mm	3.5mm
Charging Port	Micro USB	Type C	Type C
Gain Switch	Yes	Yes	Yes
Bass	Yes	Yes	Yes
Input Choice	Switch	Button	Switch
Boost	Yes	Yes	No
Filter setting	Button	Button	Button
USB Receiver Chip	XMOS U8	XMOS XU208	XMOS XU208
Coaxial/Optical Receiver Chip	CS8422	CS8422	CS8422
Coaxial/Optical Support DSD or not	Not support	Support DSD 64( DOP)	Not support
FPGA	No	Altera-EPM240T	No
DAC Chip	AK4490	AK4493	AK4490
Singal Amp Chip	OPA1612	OPA1612 ( Support to replace two chips)	NE5532 (Support for Op-amp rolling )
Circuit Amp Chip	BUF643U	BUF643U	BUF643U
Output power	500mW（32 Ω）	1000mW ( 32Ω）	500mW（32 Ω）
Frequency	USD/SPDIF:	USD/SPDIF:	USD/SPDIF:
	20Hz~20kHz(±0.5dB)	20Hz~20kHz(±0.5dB)	20Hz~20kHz(±0.5dB)
	Amp: 10Hz~100kHZ(±0.5dB)	Amp: 10Hz~100kHZ(±0.5dB)	Amp: 10Hz~100kHZ(±0.5dB)
Sample Rating	PCM: 32bit/384KHZ	PCM: 32bit/384KHZ	PCM: 32bit/384KHZ
	DSD 256	DSD 256	DSD 256
THD+N	0.0025%	0.0016%	0.0025%
S/N	112dB	117dB	115dB
Battery Capacity	3.7V 4000 mAh	3.8V 5000mAh	3.7V 4000 mAh
Battery Life	>11H( USB in)	>13H( USB in)	>9H( USB in)
	>16H ( SPDIF in)	>19H ( SPDIF in)	>12H ( SPDIF in)
	> 23H ( AUX in )	> 40H ( AUX in )	> 16H ( AUX in )
Charging Time	5H ( Fast charging)	4.5H ( Fast charging)	5H ( Fast charging)
	11H ( Slow charging)	11H ( Slow charging)	11H ( Slow charging)
Size	139.5*75*23mm	139.5*75*23mm	139.5*75*23mm
Weight	270g	276g	260g

 

Power:

Power is provided by two 4000 mAh lithium polymer cells stacked in the center of the unit.   Battery life is listed at >13 hours for USB input, >21 hours for Coaxial input, and >40 hours if bypassing the dac portion and only using the amp section of the unit.  I had no trouble getting over 12 hours on USB and 18 on Optical so find the provided numbers to be believable and not overly optimistic as they often are.

 

Controls:

The Controls are divided into three groups, 3 buttons down the left side, one switch on the rear of the unit, and three front control switches.   I’ll cover them in that order below.

Side controls from front to rear are display which turns the backlight on the volume knob on and off,  the next is SRC which is only functional when using the coax/optical inputs.  SRC allows the user to set the bit rate or  forcibly up-sample by setting input to 48, 96, or 192kHz.   Lastly the Filter button that allows the user to choose the PCM filter in use.  Sadly the display just shows PCM1-4 and doesn’t give a clearer explanation of the filter.  1 is sharp, 2 is slow, 3 is short delay sharp, and 4 is short delay slow.  For me it typically stays on PCM3.   DSD has 2 options as well and depending on the input file sets the filter as shown below:

 

On the rear of the unit, a single battery cutoff switch allows the user to bypass the battery entirely and operate from USB power via the DC input port.  It should be noted the unit will not operate with just the data cable attached as it will not draw power over the data line.

Front controls from left to right are input, bass, and gain.   Input allows switching between coax/optical, usb, and analog input.   Optical/coax is limited to 24/192 and PCM only while USB supports 32/384 and DSD256.    When using the add-on bluetooth module, the Analog input is used.    Bass boost is an on/off proposition and as mentioned in the sound notes introduces a large bump to most everything below about 400Hz.    The Gain switch is a 3 position switch with +6,+9, and +16dB.  At the lowest gain, most iems will do well although a few really sensitive ones may still have some hiss.  At the high end, the Beyer 600Ω models are easily driven to louder than listening volumes.

 

Sound:

Bass:

Bass is very similar to the other XD05 family members and without the bass switch active, bass is clean and potent without being too aggressive.  The bass boost switch is still a no-go for me as it boosts everything below about 400Hz and introduces considerable bloat.   With full-sized cans that need power, the 500mW  is enough to fully drive them so there is no loss of lows due to limited power output with all but the most power hungry models (He6).   It did an admirable job of pushing the Fostex T50rp driver well and the Beyer 600Ω as well.  The low end shares a lot of the dynamics with the plus and has good texture and separation which is a nice bonus at this price point.

 

Mids:

The basic presents clean mids depending on the op-amp in use. I did find when rolling op-amps that I could introduce a little more warmth and texture at the same time by rolling in the Muses02 in place of the standard op-amp.   The 2134 was also a good budget pick as it added a little warmth as well.   Those looking for completely linear sound will prefer the stock but those looking for a bit more musical voice may want to try one of the others mentioned.   The stock does not lift vocals or push the upper-mids / lower treble forward.     Overall, good detail and textures and a clean presentation if slightly cool.

 

Treble: 

Again we have good detail without introducing coloration or exaggerations.    Extension is quite good and air and sparkle at the top end seem much more limited by choice of headphone/earphone than by the Basic.    On low gain, I found all but the most sensitive in-ears remained silent while on higher gain levels some hiss became evident on most sensitive models.  The Magaosi K5 that is renowned for hiss does have some audible noise even on low gain so those with high sensitivity in ears will likely be better served with something a bit lower powered.   It is clear that the basic is built with full sized cans in mind and does its best work in that arena.

 

Bluetooth:

The unit does not support Bluetooth by itself, but does have an add-on, the 05BL Pro that adds this functionality.  I have an 05BL Pro that I had previously used with the other XD-05 models so tested its compatibility.  The unit works well and gave the basic LDAC and AptX-HD input in addition to its other options.  My biggest complaint on the Bluetooth unit is the fact that it obstructs the input ports and the battery cutoff switch so it is impossible to use Bluetooth when setup as a desktop amp as it blocks access to the USB Power input.     My take away is while the Bluetooth add-on works well, the XD-05 Basic is really at its best with full sized wired headphones and those looking for a Bluetooth solution can likely find more user friendly solutions for the same spend (even in Xduoo’s product line – see XP-2 Pro).

 

Comparisons:

I have attempted to compare other similar devices in the market.  These are all entry level products and feature sets differ.

 

Fiio Q1 Mk 2  $129 list

The Q1 is billed as the dac/amp for Apple but works equally well with USB input from other sources.  the Q1 uses the  AK4452 chip meaning it may get hard to find due to shortages.  Both devices are well made with the Q1 being slightly smaller and lighter and with rounded edges maybe a bit more pocket friendly.   That is where the similarities end though.  The Q1 is clearly designed with iems in mind while the Basic is designed with full sized headphones in mind.   Even with its most potent balanced output, the Q1 is only capable of roughly ½ the output power of the Basic and distortion becomes a problem when you get close to that limit.     The Q1 is quieter on low gain than the Basic as a result of its lower output power and may be prefered by those looking for something to use with high sensitivity iems, otherwise the Basic is much more versatile with more power and the addition of Coax, and optical inputs that are lacking on the Q1.

 

iFi hip Dac $129 list

The Hip Dac is iFi’s entry level device and has a basic feature set and USB input only.    The Hip-Dac is roughly ½ the size of the Basic and with rounded edges, again a bit more pocket friendly as a result.   Internally the two are similar with both offering 32/384 PCM and DSD256 but the Hip-Dac is MQA certified where the Basic is not.  Power is roughly equal if comparing the balanced output of the Hip-Dac to the standard output of the Basic.  So again the Hip-Dac is aimed more at iems while the basic is aimed at larger headphones.    If you need MQA, the Hip-Dac is an inexpensive entry point, but if it isn’t a concern, the Basic is much more flexible for the same spend.

 

Topping NX4 $159 list

The reigning King of budget, the Topping NX4 is slightly more expensive than the Basic but those impressed by stats and measurements love the high SNR and low THD offered by the NX4.   The NX4 is smaller by about ½ again and lighter with rounded edges so again more pocket friendly.   Internally, the NX4 uses the ESS9038 mobile chip so has an advantage of 32/768k PCM  and DSD512 support when compared to the basic.   The Basic hits back with additional Coax and Optical inputs, better battery life, and more power although on that last count its fairly close.   The Basic will power 150Ω and higher headphones better but below that differences are less notable.   One thing to note is the NX4 has not been updated so uses micro-USB rather than the newer USB-C connectors and may be more prone to breakage as a result.    I don’t think the Basic is going to dethrone the king unless you need more power than Nx4 can provide or the extra $40 for the NX4 comes into play.  Both are great devices so hard to go wrong either way.

 

Chord Mojo $500 list

It never fails even when reviewing budget items somebody will ask, but how does it compare to the mojo.  So what does spending 4 times as much get you?  The mojo supports 32/768 USB or coaxial input while the optical on Mojo is actually more limited than the Basic (96/24).    Mojo’s battery life is considerably less at 8 hours and many including myself have had issues with the Mojo getting outright hot while charging, (especially while charging during use).    Output power on Mojo is 50% higher than the Basic but somehow it manages a lower noise floor in the process so works equally well with big cans or sensitive in-ears.   The fact that Mojo splits its output between two 3.5mm outputs also calls into question how much of that output is really available to either jack if both are in use.   One of the big upsides to Mojo is that rather than using a dedicated DAC, it uses a microprocessor (Xilinx Artix 7) thus can be re-programmed to support newer standards rather than being hardware limited.  With the current firmware.   Both are aluminum shelled with the Mojo being a bit more artistic while the controls on the Basic are a bit more easily understood and the display makes more sense than the Mojo’s colored buttons arrangement.   Mojo is starting to show its age with micro-USB ports instead of USB-C.   Having been several years since release, it is possible that a Mojo2 could be on the horizon, but to date no announcement has been made that I am aware of.

 

Conclusion:

I have long been a fan of the XD-05 series and have said more than once that I thought the XD-05 might be the best product Xduoo makes.  The good news is the basic is very much part of that family and has done nothing to change my impression.    The basic retains all of the things that made the original model  a hit and adds some updates that even the Plus missed (battery cutoff).    The ability to swap op-amps gives the end-user some tuning options that most others don’t.  Tonality is good as it neither tries to add anything nor does it particularly detract from any single element.   The option of USB-C, coax, optical, or analog input makes it a truly versatile travel companion, while the battery cutoff and 500mW of output power make it a capable desktop companion as well.     The bass boost still sucks and is best avoided in my view, and bluetooth functionality blocks the use as a desktop product with the battery cutoff so obviously wasn’t well thought through.    The XD-05 Basic  is a solid option and a good value but not without some limitations.  I can live with that as the core functions it offers are the ones I use daily and the things it doesn’t do well, I probably won’t miss.     Definitely worth a listen.