UDA18 USB DAC with Isolated USB signal
The UDA18 is an update to our 9018D series and we’ve added several features. The biggest change is the USB i2s isolation. We have earlier made a standalone i2s/DSD isolator board, and we’ve now included this ISO7240 isolator chip into this DAC. The benefits are lower interference and noise from USB, which makes the sound clearer with a darker background.
DAC with digitally adjusted lossless volume control
The DAC chip is the ES9018K2M that we also use in the 9018D and the other 9018 series DACs. It is great chip with a very transparent sound and also has the ability to control the volume digitally. We use a potmeter to set the output volume level from the DAC chip. The sound doesn’t have to go through this potmeter as normally with an analog volume control. In the UDA18 the DAC chip reads the setting of this volume control potmeter and sets the output volume accordingly.
Optional DC power input
The DAC can conveniently power from USB, but you can also connect a high quality DC power to further improve the sound quality. It will automatically detect and power from external DC when connected. When you use an optical signal then you have to connect power either from USB or DC supply.
No drivers needed
The UDA18 uses the Savitech SA9227 USB receiver in asynchronous USB mode. It doesn’t need any drivers in Mac and Linux, and you can set the H/F switch to “F” (audio class 1.0) for plug and play without needing drivers in older Windows versions. In Windows 10 you no longer need drivers for higher sample rates. There are drivers available for older Windows versions enabling >96kHz and DSD (audio class 2.0 mode, set the switch to “H”).
iPhone compatibility: It works with original apple lightning to USB adaptor camera connection kit (external DC power required). It does not work with the $4.99 cable that we sell, nor the lightning cable we sell as that one is for microUSB connectors.
Android compatibility: So far we have tested with Xiaomi phone only. It works natively also without external power connected.
The output stage chip is TPA6120A. It has enough power for most headphones and can also drive line level loads such a preamps, amplifiers. The differential signal from the ES9018K2M DAC chip is fed to an OPA2134 before the TPA6120A.
- Chips: SA9227, ES9018K2M, TPA6120A
- Digital lossless volume control
- Isolated I2s/DSD signal with isolator chip
- Two inputs: Optical and USB selectable by switch
- Optional DC input. Can run on USB power when DC power is not connected
- USB input supports all frequency rates up to 384kHz 16/24/32 bit and DSD128
- Optical inputs supports up to 192kHz
- High speed/Full speed switch. Chose Full speed for no drives use in Windows up to 96kHz/24bit
- Asynchronous USB transfer. DAC is clocked by 100MHz oscillator
- Inputs: USB (type-B), Optical SPDIF selectable by switch
- Output: 3.5mm connector
- SNR: 120dB
- THD: -117dB
- Output power: 200mW @30ohm, 40mW @250ohm, 17mW @600ohm.
- DC input: 5-6VDC min 400mA (not included)
- DC input plug: 5.5/2.1, inside pin is positive.
- Size: 10 x 8 x 3 cm
I am very thrilled on this DAC! UDA18 offers an excellent sound experience whether plugged to power (I am using a low noise and audiophile-grade power supply, iFi iPower 5V 2.5A) or via a USB OTG cable. No burn-in was needed at all, sound was great, open and very detailed from the very first listening session. Using the power supply, my gut feeling is that the sound pressure is stronger, even if listening is pleasant and very closed to optimal just with the USB OTG cable. However, thanks to the external power supply I can use my analog source (eg, CD player) more easily, it’s just a matter of flipping the USB/analog switch.
Because someone wrotes that the headphoneamp is weak with Beyerdynamic 770 80ohm . I have the same haedphone and have more headroom than I can ever use.
I decided to add, that device sounds even better with burn in. Thanks hifime, great job!
Nice and melodic sound, clean and mellow highs, nice midrange, but im sad to say that headphone amp is weak and beyerdynamics dt 770 pro 80 not powered enough for 100% satisfaction. Hope your next device with ess9038 will be with stronger headphone amp.
Shani shabath –
Well this my third dac and it came with some problems which the company support helpd and were very quick about it so 10/10 for support
The dac itself is a big step up sound is very clear and open
And amazing sound stage
I can only recommend this company for making great products in a very affordable price range
shinra ceo bman –
10/10 very detailed. imaging is great. cleaned up my music, woke up my fidelio x2 tightened up the low end, highs are less exhausting and sharp, more natural….. i do wish it came with the 1.5m usb cable but that’s a small complaint and has nothing to do with how amazing this dac sounds
I’ll start with the frustration. My unit arrived the day Hifime announced a 9038-based model. I know the 9038 won’t be $159, but I would definitely have ordered the 9038 instead.
The 9018 is a definite jump from my Hifime 9023: better imaging, bass, and detail. A 5 volt battery extender adds to the difference.
I mostly listen through speakers.The UDA 18 works seamlessly with Linux and there’s enough gain to overcome Linux not being loud enough.There’s plenty of detail even at low volume. Transients are really good. The highs can be slightly harsh at very loud volume, butthe issue goes away with the handful of 24/192 remasters I have.
For portable use, I use it with a micro USB converter, an android tablet(my Samsung can power the DAC w/out the battery btw), and a pair of 1More Triple Driver iems. I’d been happy with a Fiio X3 Gen 2, but the UDA18 is the difference between a really good upright and a grand piano.
I’ll give an initial review here and update in a week or so.
Right out of the box I can tell this is a great implementation of the Sabre 9018 chip, I already own a HiFime Sabre 9018 USB DAC with isolator and can tell the UDA18 sounds better, more integrated and cohesive.
The sound is warm and open with a wide soundstage both left to right and front to back. The trebles are not harsh, which has been a criticism with past implementations of the Sabre 9018.
I initially fired it up with just the USB cable and it sounds great, but adding a 6V DC power supply improves the sound even more.
I shall try it with an optical cable over the next few days and with the drivers when they are available.
Going with the OPA2134 jfet chips was an excellent idea, they are my favorite op-amps outside of the Sparkos and Burson op-amps. The OPA2134 are very clean and detailed op-amps.
HiFime get’s a 10/10 at the initial listening stage.