I received a request from the manufacturer of this product to review it. The UD-01 is a little bigger than a portable headphone amp, and is built around the Burr Brown PCM 2702E DAC chip with a Burr-Brown OPA2604 low pass filter as the output stage. It comes with a wall-wart power supply, but there is an option for a much upgraded power supply, about which, more later.
Pics:
I reviewed the KingRex products being fed Apple Lossless files from iTunes via the USB output of my Dell XPS Core 2 Duo laptop, and with the DAC in turn feeding my Decware CSP-2 headphone amp. I used mostly my Beyerdynamic DT990/600, but also used my JVC RX900’s.
OK, I will admit it: I really was not excited about reviewing this product. I’m just not all that enthusiastic about the product category of stand-alone USB DACs. The UD-01 costs $209 with the wall-wart power supply - $340 when combined with the enhanced PSU. I have a TNS Sweet-2 that is a USB DAC, tubes headphone and speaker amp with remote control that I bought for $299! And the USB DAC in that sounds pretty good.
To make matters worse, the sound of the UD-01 with the wall-wart supply was nothing special. Competent, acceptable, and better than the line out of my laptop, yes. But it was also slightly grainy, slightly rough, and slightly aggressive sounding. I wasn’t in love. I was ready to give up.
I gave KingRex some comments, and they sent me their PSU unit to use in the review. And here I encountered a new problem – the PSU was sent to be without fuses installed, and arced and shut down when I went to plug it in. Bummer.
Undeterred, KingRex sent me some fuses. And so I installed them, which was actually no easy trick, as one is on the circuit board inside of the extremely well built PSU which requires both a Phillips X and Allen wrench to get open! I was really just about ready to give up.
But I am glad I didn’t. With the PSU, the KingRex UD-01 was actually pretty special – it was a big improvement over the USB DAC built into the Sweet-2, and much better than the UD-01 with the wall wart. MUCH better. With the PSU, The UD-01 provided a smooth, transparent, highly enjoyable sound. I was very impressed. Aside from the fantastic but very expensive RedWineAudio Isabella DAC, this is the best sound I personally have had coming directly from my PC. The UD-01, with the PSU, really doesn’t have a “sound” which is a GOOD thing – it simply provided a very transparent hand-off from the hard drive to the Amplifier. And that is the nicest thing someone can ever say about a DAC.
I have felt many USB DACs were very grainy sounding, and were NOT transparent. Not so the UD-01 with PSU. The combination sounds excellent. I cannot recommend the UD-01 alone with just the wall-wart. However, the UD-01 with PSU gets an enthusiastic recommendation. It also reminds me just how important a good power supply is!
Pics:
I reviewed the KingRex products being fed Apple Lossless files from iTunes via the USB output of my Dell XPS Core 2 Duo laptop, and with the DAC in turn feeding my Decware CSP-2 headphone amp. I used mostly my Beyerdynamic DT990/600, but also used my JVC RX900’s.
OK, I will admit it: I really was not excited about reviewing this product. I’m just not all that enthusiastic about the product category of stand-alone USB DACs. The UD-01 costs $209 with the wall-wart power supply - $340 when combined with the enhanced PSU. I have a TNS Sweet-2 that is a USB DAC, tubes headphone and speaker amp with remote control that I bought for $299! And the USB DAC in that sounds pretty good.
To make matters worse, the sound of the UD-01 with the wall-wart supply was nothing special. Competent, acceptable, and better than the line out of my laptop, yes. But it was also slightly grainy, slightly rough, and slightly aggressive sounding. I wasn’t in love. I was ready to give up.
I gave KingRex some comments, and they sent me their PSU unit to use in the review. And here I encountered a new problem – the PSU was sent to be without fuses installed, and arced and shut down when I went to plug it in. Bummer.
Undeterred, KingRex sent me some fuses. And so I installed them, which was actually no easy trick, as one is on the circuit board inside of the extremely well built PSU which requires both a Phillips X and Allen wrench to get open! I was really just about ready to give up.
But I am glad I didn’t. With the PSU, the KingRex UD-01 was actually pretty special – it was a big improvement over the USB DAC built into the Sweet-2, and much better than the UD-01 with the wall wart. MUCH better. With the PSU, The UD-01 provided a smooth, transparent, highly enjoyable sound. I was very impressed. Aside from the fantastic but very expensive RedWineAudio Isabella DAC, this is the best sound I personally have had coming directly from my PC. The UD-01, with the PSU, really doesn’t have a “sound” which is a GOOD thing – it simply provided a very transparent hand-off from the hard drive to the Amplifier. And that is the nicest thing someone can ever say about a DAC.
I have felt many USB DACs were very grainy sounding, and were NOT transparent. Not so the UD-01 with PSU. The combination sounds excellent. I cannot recommend the UD-01 alone with just the wall-wart. However, the UD-01 with PSU gets an enthusiastic recommendation. It also reminds me just how important a good power supply is!
lol
).
