This is a review and detailed measurements of the WiiM Ultra network streamer, DAC, phono stage and preamplifier. It was sent to me by the company and costs US $329.
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Physical attribute are modern and attractive enough. Alas, I can't say the same thing about the graphical interface. Icons seem dated to me. They are also superfluous to what is in the App other than "now playing" screen. On that front, I am yet again disappointed by lack of volume control display even though there is plenty of room there:
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Why emphasize bit rate and sample size instead of volume control? Also lacking is any indicator that you have EQ active and if so, which profile.
On that topic, the volume controls feels like it is scratching against the case. I tried to pull it out but would not move so left it alone, leaving an unsatisfying feel.
I tried to turn Ethernet off and it warned me that I would be switching to WiFi? Why is this either or instead of both being on at the same time?
Finally, there is no off switch on the UI or the unit itself:
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The good news shows up when you look at the back and see such comprehensive connectivity, blowing away any stand-alone DAC or simple streamer. We have analog input, phono stage, and even HDMI ARC in addition to USB host capability. Alas, reading those names is next to impossible in most lighting/angles. As you see, I had to tilt the unit up for them to show up on the picture. Otherwise they wash away to same color as the case. Labels should be legible when looking down from above which the back is facing the wall.
The sophisticated app is there which instantly recognized the unit and allowed me to configure it. There is great value added here including proper crossover for bass management, EQ, etc.
WiiM Ultra DAC Measurements
I set up the unit for streaming over Ethernet from my Roon player and was greeted with excellent performance out of line out:
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The WiiM Ultra easily makes way for itself among our very competent DACs, obviating the need to use an external one:
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Noise performance is in the same class:
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Multitone performance is great:
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Here is the 50 Hz performance for comparison with Stereophile tests of DACs:
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Linearity is perfect:
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IMD test shows noise could be a bit better but distortion is nicely low:
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Jitter shows some interference as we saw with
WiiM Pro Plus but nto harmful to sound:
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Filter attenuation beyond 24 kHz is excellent:
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Frequency response is nice which is a good thing as I didn't see any option of changing the filter:
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48 kHz wideband distortion+noise is not very good:
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Increasing the sample rate fixed that indicating that there is some kind of noise shaping going on:
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WiiM Ultra Headphone Output Measurements
I started with power testing which turned out just OK performance:
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Stepping through the various load impedances shows substantial output impedance (should be near zero):
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Response is also variable. So not a serious headphone amplifier.
WiiM Ultra Phono Stage Measurements
Let's start with our dashboard using MM mode:
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And MC:
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Noise floor seems elevated which when added to mains noise, resulted in lackluster performance. Fortunately RIAA equalization is good:
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WiiM Analog Input Measurements
I configured the analog input for 24 bit/192 Khz:
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So not bad. Here is the noise performance for both 24 bit and 16:
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So better override the default 16 bits.
Frequency response is nice as and wide (at 192 kHz sampling):
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WiiM Ultra Bluetooh Measurements
Someone suggested that I test the Bluetooth input using LDAC codec. I spent half hour trying to enable that and I could not. My Android phone would constantly show it in gray indicating the target device doesn't support it. A quick google found the FAQ for WiiM Ultra stating that it only supports SBC and AAC.
Both turned in poor performance due to the nature of those codecs and their encoders in BT application:
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I highly recommend company pursue supporting LDAC.
Conclusions
WiiM Ultra nails streaming performance with an excellent codec implementation. Rich functionality is another plus as is the App. The new display didn't do much for me and if anything, was a bit of a negative even though in general I am a fan of such things. Headphone output is not useful for serious listening. Phono stage may be OK if noise is not an issue. Finally, Bluetooth support is a let down with lack of LDAC support.
I think an overhaul of the GUI with a better platform and addition of LDAC would go a long way to justify the higher cost and display.
I am going to recommend the WiiM Ultra. There is such incredible amount of capability here that when combined with excellent codec and reasonable cost, it is hard to pass on it.
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