This is a review and detailed measurements of the Loxjie D30 DAC with Bluetooth and headphone amplifier. It was kindly sent to me by the company. It costs US $160 from the one site I can find that is selling it currently.
The D30 is a departure from previous Loxjie products with odd shapes and such:
The high resolution display is informative and quite nice. A cool feature is that it remembers the headphone volume level and pre-out independently. So there is no risk of blowing up one or the other with inappropriate level set for the other device.
I love that it has an included mains power supply so you don't have to deal with an external supply:
Clearly good attempt has been made to get the functionality right first before worrying about looks.
DAC Audio Measurements
The output was a bit higher than 2 volt that we aim for in our testing so I dialed it down a bit to get to 2 volts:
This reduced the SINAD by 1 dB which is inline with what Loxjie has published. At 114 dB, this firmly places the D30 in excellent category of all DACs tested:
Dynamic range falls in the same category:
Intermodulation distortion is excellent:
32-tone signal resembling "music" shows very low distortion levels, albeit with a bit of uptick in midfrequencies:
Jitter on both USB and Toslink was more than what I like:
THD+N versus frequency was fine in one channel but worse in the other:
Precision as reflected in our linearity test is excellent:
Usual set of filters are provided:
Headphone Amplifier Measurements
Let's start with power output using 300 ohm:
My target here is 100 milliwatt and the D30 misses that by fair bit. So it will get loud but will have limits. Fortunately there is no sign of distortion so you would be good to max volume.
Switching to 33 ohm we get:
Signal to noise ratio for very low output level is not that great:
Bluetooth Audio Measurements
There has been requests on and off for Bluetooth performance measurements. Given the lossy nature of the codecs used in BT, what you see reflects that performance and not the DAC itself. As such, the results should be transferrable to many other DACs with Bluetooth inputs (or Bluetooth devices in general). The source here was my Samsung S8+ so there may be some variation depending on how good the encoders are in my phone.
Let's start with the default and most common codec, aptX:
The spectrum shows the typical signature of this codec with filtering of frequencies above 5 kHz. We have lost some 50 dB in fidelity versus uncompressed as well. Noise has sharply increased.
Here is the original music codec in BT, namely SBC:
The filtering is gone but replaced with a lot of junk. Performance is up 4 dB in total.
Both SBC and aptX are non-perceptual codecs. They don't have a psychoacoustics model to decide what to keep and what not to. They rely on inherent redundancy in the music data to compress it (in case of a single sine wave used here, that should have been most efficient). In contrast, the next choice, the AAC codec, is an excellent perceptually based lossy codec which makes encoding much more "expensive" in the form of CPU cycles but should generate better results:
We do get better performance to the tune of 11 dB better SINAD. But this is still horrible. A single sine wave should be a walk in the park for a perceptual codec. There is no excuse for noise around the shoulders of our main tone. The other spikes are harmonic distortion which may be generated by the analog output of the Bluetooth module used.
I tried LDAC but it did not work so I assume it is not supported in D30. If possible I like to see the DAC display the codec in use for Bluetooth.
Headphone Listening Tests
The D30 had no trouble powering my very low sensitivity, low impedance Drop Ether CX. It got loud enough to be very usable with no hint of distortion. Normal listening would be at 80 to 90% volume. Note however that with music recorded at low level, I had to ride the volume to max. Same situation existed with Sennheiser HD-650 headphones. No distortion, loud enough to almost get uncomfortable and excellent fidelity.
Conclusions
The Loxjie targets the most common configuration and features one needs for a desktop product: DAC, headphone amp and bluetooth. The DAC performance is excellent. Anything better would cost you hundreds of dollars more. The headphone amplifier has very good noise and distortion but limited power. And too high a noise floor for sensitive IEMs. Still, as an included amplifier, it does the job for most people.
I debated if I should give the D30 the golfing panther or "I like it" one. At the end, I remembered all the requests I get for a great all-in-one DAC and headphone amp at a reasonable price and this fits the bill most perfectly. To get better, you need to go to a stack of two boxes at a cost of $200. And analog volume control which may cause channel differential.
I am happy to recommend the Loxjie D30.
------------
As always, questions, comments, recommendations, etc. are welcome.
Spent the entire yesterday canning our latest harvest. Had planted a bunch of beautiful carrots back in spring. Did not eat them fast enough so decided to pickle them. Here is a shot of them ready to go:
They have stronger color variations before pealing. Many have orange insides despite the skin being different on the outside. I did get a kick out of the green one being that way on the outside and inside. Bye carrots! See you next late spring.
Helper is out there digging the new trench for the septic pipe. It is right at the foundation of the house and above deck. And the heat pump. Hopefully when it is all done the side of the house won't cave in! Your prayers in the form of monetary donations would be much appreciated: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The D30 is a departure from previous Loxjie products with odd shapes and such:
The high resolution display is informative and quite nice. A cool feature is that it remembers the headphone volume level and pre-out independently. So there is no risk of blowing up one or the other with inappropriate level set for the other device.
I love that it has an included mains power supply so you don't have to deal with an external supply:
Clearly good attempt has been made to get the functionality right first before worrying about looks.
DAC Audio Measurements
The output was a bit higher than 2 volt that we aim for in our testing so I dialed it down a bit to get to 2 volts:
This reduced the SINAD by 1 dB which is inline with what Loxjie has published. At 114 dB, this firmly places the D30 in excellent category of all DACs tested:
Dynamic range falls in the same category:
Intermodulation distortion is excellent:
32-tone signal resembling "music" shows very low distortion levels, albeit with a bit of uptick in midfrequencies:
Jitter on both USB and Toslink was more than what I like:
THD+N versus frequency was fine in one channel but worse in the other:
Precision as reflected in our linearity test is excellent:
Usual set of filters are provided:
Headphone Amplifier Measurements
Let's start with power output using 300 ohm:
My target here is 100 milliwatt and the D30 misses that by fair bit. So it will get loud but will have limits. Fortunately there is no sign of distortion so you would be good to max volume.
Switching to 33 ohm we get:
Signal to noise ratio for very low output level is not that great:
Bluetooth Audio Measurements
There has been requests on and off for Bluetooth performance measurements. Given the lossy nature of the codecs used in BT, what you see reflects that performance and not the DAC itself. As such, the results should be transferrable to many other DACs with Bluetooth inputs (or Bluetooth devices in general). The source here was my Samsung S8+ so there may be some variation depending on how good the encoders are in my phone.
Let's start with the default and most common codec, aptX:
The spectrum shows the typical signature of this codec with filtering of frequencies above 5 kHz. We have lost some 50 dB in fidelity versus uncompressed as well. Noise has sharply increased.
Here is the original music codec in BT, namely SBC:
The filtering is gone but replaced with a lot of junk. Performance is up 4 dB in total.
Both SBC and aptX are non-perceptual codecs. They don't have a psychoacoustics model to decide what to keep and what not to. They rely on inherent redundancy in the music data to compress it (in case of a single sine wave used here, that should have been most efficient). In contrast, the next choice, the AAC codec, is an excellent perceptually based lossy codec which makes encoding much more "expensive" in the form of CPU cycles but should generate better results:
We do get better performance to the tune of 11 dB better SINAD. But this is still horrible. A single sine wave should be a walk in the park for a perceptual codec. There is no excuse for noise around the shoulders of our main tone. The other spikes are harmonic distortion which may be generated by the analog output of the Bluetooth module used.
I tried LDAC but it did not work so I assume it is not supported in D30. If possible I like to see the DAC display the codec in use for Bluetooth.
Headphone Listening Tests
The D30 had no trouble powering my very low sensitivity, low impedance Drop Ether CX. It got loud enough to be very usable with no hint of distortion. Normal listening would be at 80 to 90% volume. Note however that with music recorded at low level, I had to ride the volume to max. Same situation existed with Sennheiser HD-650 headphones. No distortion, loud enough to almost get uncomfortable and excellent fidelity.
Conclusions
The Loxjie targets the most common configuration and features one needs for a desktop product: DAC, headphone amp and bluetooth. The DAC performance is excellent. Anything better would cost you hundreds of dollars more. The headphone amplifier has very good noise and distortion but limited power. And too high a noise floor for sensitive IEMs. Still, as an included amplifier, it does the job for most people.
I debated if I should give the D30 the golfing panther or "I like it" one. At the end, I remembered all the requests I get for a great all-in-one DAC and headphone amp at a reasonable price and this fits the bill most perfectly. To get better, you need to go to a stack of two boxes at a cost of $200. And analog volume control which may cause channel differential.
I am happy to recommend the Loxjie D30.
------------
As always, questions, comments, recommendations, etc. are welcome.
Spent the entire yesterday canning our latest harvest. Had planted a bunch of beautiful carrots back in spring. Did not eat them fast enough so decided to pickle them. Here is a shot of them ready to go:
They have stronger color variations before pealing. Many have orange insides despite the skin being different on the outside. I did get a kick out of the green one being that way on the outside and inside. Bye carrots! See you next late spring.
Helper is out there digging the new trench for the septic pipe. It is right at the foundation of the house and above deck. And the heat pump. Hopefully when it is all done the side of the house won't cave in! Your prayers in the form of monetary donations would be much appreciated: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
