slim.a
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I have received my review sample of the Kingrex UD384 last week and thought I should perhaps share some preliminary impressions.
Description of the UD384 and the UPower:
Below are some specs on the UD384 and UPower:
UD384:
The Kingrex UD384 is an async USB DAC and Digital to Digital (USB to Spdif) converter capable of up to 24/384 sample rates (from its USB input).
The Kingrex UD384 can be operated either from a regular 7.5v SMPS or from the UPower, which is the optional battery power supply.
Below are the specs I was able able to find:
UD384 (32bits/384Khz USB DAC )
Input: USB x 1
Analog output: RCA x 2 (Rx1 Lx1)
Digital output :SPDIF x 1
Sampling rate support :44.1Khz, 48Khz, 88.2Khz, 96Khz, 176.4Khz, 192Khz, & 384Khz(384Khz for USB DAC only)
Supported bit rate: 16 / 24 /32bit
USB:2.0 high speed
Adaptive Clock Generator for Audio Streaming Synchronization
Asynchronous mode changeable through DFU Tool
Power requirement: 7.5V/250mA
Size: 110x82x24mm
Suggested MSRP : $479/pc
U Power:
Pure DC output battery power supply unit
I. Two output :
A. 2.5mm DC jacket: 7.5V DC output
B. USB A :5V DC output(through linear regulator)
II. Major component: High quality Sanyo Li-ion battery.
III. Power volume: 2600mA/hr. Included special design for isolated protect circuitry for two Li-ion batteries.
IV. Using fully high quality aluminum for styling & cooling.
V. Low battery indicator design for charging reminding.
VI. CHG/DC OUT switch. Fully isolated the charging and discharging. It will free the AC noise from the charger.
VII. Parallel charging- each battery cell could charge to its maximum by the design.
Suggested MSRP: US$189/pc
Initial Impressions:
Note:
Before doing any serious listening, I let the Kingrex burn-in for around 100 hours. I did not notice any obvious change in sound. Kingrex recommends 200 hours of burn-in.
Soundstage:
What surprised me about the Kingrex is the spacious and well layered soundstage. Just before receiving the UD384, I acquired the Audiophilleo2 which I have been using with my reference DAC, the Audio-gd dac19dsp. The AP2 was already an improvement in the soundstage department in comparison with the previous transports I was using (namely the Battery powered Jkeny MK1 and the tweaked A-GD DI).
But the UD384 (with the UPower in place) was definitely better in the soundstage department. While it was perhaps not as wide as the AP2 + A-gd DAC19DSP, it was definitely deeper and more layered. Along with the Beyer T1, the soundstage was gigantic (in certain tracks) and there was still a pinpoint accuracy.
Though, I should probably mention that the soundstage was much better at 24/96 sample rates and higher than it was at the RBCD 16/44 frequencies. The UD384 belongs to the class of converters that can benefit noticeably from upsampling. While some might view as a negative, I personally view as a positive since it allows the end user to try out different upsampling modes for different “flavors” and results.
I haven’t had time to experiment much with different settings but upsampling 16/44 to 24/192 with SoX on Foobar seemed to give good results with different tracks.
Transparency and Definition:
With the optional UPower power supply, the UD384 can dig very deep into the recordings. With high resolution material (24/96 and 24/192), the UD384 seems to be as good as I ever heard those songs on my systems.
Timber and tonal balance:
While I thought I noticed some brightness fresh out of the box, the UD384 turned out to be relatively well balanced once I listened to it for a more prolonged period of time (after the 100 burn-in period).
The pianos and violins are slightly less convincing on the UD384 than they are on my AP2+DAC19DSP reference, and the UD384 does not seem to reach as deep in the lowest frequencies as my reference source. But keep in my mind that the price of the AP2+DAC19+various tweaks is more than three times the price of the UD384.
Overall, for someone who does not listen much to unamplified/unprocessed instruments such as violins and pianos, it is possible that what I noted above would be a non-issue.
For most modern music, the UD384 sounded very convincing and better than what the AP2 + A-GD FUN gives you for example.
Note: Kingrex doesn’t disclose what type of dac chip is being used inside.
Preliminary conclusion:
While I still haven’t formed a definitive opinion on the Kingrex UD384, as I still need to listen more and try different settings (regular SMPS vs. UPower, different sample rates,…), it seems that Kingrex has done a good job for the asking price. One gets in the same “package” a good usb to spdif converter, a good dac and a very smart external power supply. One shouldn’t need to worry about digital coaxial cables and power filtration (power cords and power filters). It should give a good repeatability of results from one system to the other.
More details later on when I spend more time with the unit...
Description of the UD384 and the UPower:
Below are some specs on the UD384 and UPower:
UD384:
The Kingrex UD384 is an async USB DAC and Digital to Digital (USB to Spdif) converter capable of up to 24/384 sample rates (from its USB input).
The Kingrex UD384 can be operated either from a regular 7.5v SMPS or from the UPower, which is the optional battery power supply.
Below are the specs I was able able to find:
UD384 (32bits/384Khz USB DAC )
Input: USB x 1
Analog output: RCA x 2 (Rx1 Lx1)
Digital output :SPDIF x 1
Sampling rate support :44.1Khz, 48Khz, 88.2Khz, 96Khz, 176.4Khz, 192Khz, & 384Khz(384Khz for USB DAC only)
Supported bit rate: 16 / 24 /32bit
USB:2.0 high speed
Adaptive Clock Generator for Audio Streaming Synchronization
Asynchronous mode changeable through DFU Tool
Power requirement: 7.5V/250mA
Size: 110x82x24mm
Suggested MSRP : $479/pc
U Power:
Pure DC output battery power supply unit
I. Two output :
A. 2.5mm DC jacket: 7.5V DC output
B. USB A :5V DC output(through linear regulator)
II. Major component: High quality Sanyo Li-ion battery.
III. Power volume: 2600mA/hr. Included special design for isolated protect circuitry for two Li-ion batteries.
IV. Using fully high quality aluminum for styling & cooling.
V. Low battery indicator design for charging reminding.
VI. CHG/DC OUT switch. Fully isolated the charging and discharging. It will free the AC noise from the charger.
VII. Parallel charging- each battery cell could charge to its maximum by the design.
Suggested MSRP: US$189/pc
Initial Impressions:
Note:
Before doing any serious listening, I let the Kingrex burn-in for around 100 hours. I did not notice any obvious change in sound. Kingrex recommends 200 hours of burn-in.
Soundstage:
What surprised me about the Kingrex is the spacious and well layered soundstage. Just before receiving the UD384, I acquired the Audiophilleo2 which I have been using with my reference DAC, the Audio-gd dac19dsp. The AP2 was already an improvement in the soundstage department in comparison with the previous transports I was using (namely the Battery powered Jkeny MK1 and the tweaked A-GD DI).
But the UD384 (with the UPower in place) was definitely better in the soundstage department. While it was perhaps not as wide as the AP2 + A-gd DAC19DSP, it was definitely deeper and more layered. Along with the Beyer T1, the soundstage was gigantic (in certain tracks) and there was still a pinpoint accuracy.
Though, I should probably mention that the soundstage was much better at 24/96 sample rates and higher than it was at the RBCD 16/44 frequencies. The UD384 belongs to the class of converters that can benefit noticeably from upsampling. While some might view as a negative, I personally view as a positive since it allows the end user to try out different upsampling modes for different “flavors” and results.
I haven’t had time to experiment much with different settings but upsampling 16/44 to 24/192 with SoX on Foobar seemed to give good results with different tracks.
Transparency and Definition:
With the optional UPower power supply, the UD384 can dig very deep into the recordings. With high resolution material (24/96 and 24/192), the UD384 seems to be as good as I ever heard those songs on my systems.
Timber and tonal balance:
While I thought I noticed some brightness fresh out of the box, the UD384 turned out to be relatively well balanced once I listened to it for a more prolonged period of time (after the 100 burn-in period).
The pianos and violins are slightly less convincing on the UD384 than they are on my AP2+DAC19DSP reference, and the UD384 does not seem to reach as deep in the lowest frequencies as my reference source. But keep in my mind that the price of the AP2+DAC19+various tweaks is more than three times the price of the UD384.
Overall, for someone who does not listen much to unamplified/unprocessed instruments such as violins and pianos, it is possible that what I noted above would be a non-issue.
For most modern music, the UD384 sounded very convincing and better than what the AP2 + A-GD FUN gives you for example.
Note: Kingrex doesn’t disclose what type of dac chip is being used inside.
Preliminary conclusion:
While I still haven’t formed a definitive opinion on the Kingrex UD384, as I still need to listen more and try different settings (regular SMPS vs. UPower, different sample rates,…), it seems that Kingrex has done a good job for the asking price. One gets in the same “package” a good usb to spdif converter, a good dac and a very smart external power supply. One shouldn’t need to worry about digital coaxial cables and power filtration (power cords and power filters). It should give a good repeatability of results from one system to the other.
More details later on when I spend more time with the unit...
