My Ultra tests

[canard]

hihi

 

[Steve Woodhouse]

And there are different kinds of multitones, NID ones will produce distortions differently.

But rarely do you see a significant difference.

 

[canard]

But """"""rarely"""" do you see a significant difference.

rarely..... not never..big new ;-)))

 

[onlyoneme]

 

[onlyoneme]

Just an example, above is not from the Ultra.

 

[Steve Woodhouse]

Just an example, above is not from the Ultra.

What’s that from?

 

[Imsjry]

So…how does the Ultra SOUND compared to other DACs?

 

[Steve Woodhouse]

So…how does the Ultra SOUND compared to other DACs?

Someone has opened another thread for that.

Listening impressions with the WiiM Ultra compared to the WiiM pro+ and compared to other streamers

There is ( strangely enough ) almost no subjective reviews how the WiiM ultra sounds compared to the pro+ and other streamers like the Bluesound node or Eversolo . Please share your subjective impressions about the sound quality of the WiiM ultra streamer in this thread. Dont make any links to...

forum.wiimhome.com

 

[Griff]

I don't know. Maybe it's somehow related to clocks, worse rise/fall times can be also an effect of the LPF, but I'm just guessing.

Thanks I wondered if it was clocking not aware of the possiblity of impact of lpf as @pieterv1 also mentioned

 

[canard]

It's going to be a long time process, but I will try to add a new content periodically. Everything based on the pre prod device which is PCB ver 2 unit.

Just one thing at the beginning, a comparison of the waveforms over the digital coax output, tested with the oscilloscope and 192 kHz sample rate test signal, and terminated at 75 ohms.

This is for the Ultra:

View attachment 8954

And this is for the Pro/Plus:

View attachment 8955

Ideal and perfect waveforms would show rectangles. In the real world it should be as close as possible to the ideal one.




A rough comparison of the Pro Plus with the Ultra, THD vs frequency, 192 kHz sample rate. It's not a THD+N, so it's not a sinad. And this is over the analog output using full scale sine signals.

View attachment 8971

The "hills" here would require some explanation, but I'll spend some time on that a little later with my personal perspective on other measurements results which I've faced.




Few words on the noise on the analog output. I use 192 kHz sample rate and a dithered silence file to keep the output active.

First result is taken when the Ultra is connected directly to my ADC, screen is off:

View attachment 9045

and with the screen on:

View attachment 9046

10 kHz component (and harmonics) appear.

Now the same test but also with the scaler, so that's the setup I use most of the time, screen off:

View attachment 9047

and the screen on:

View attachment 9048

One of the differences between above setups is the input impedance, 1.2 kOhm vs 100 kOhm. I've made some additional tests with RME UCX II and 5 kOhm and 9 kOhm impedances, and observed results lied between these above, being closer to the ADC alone with its low input impedance. I guess that the noise pollution from the PSU is strong enough to reveal itself when high impedance input is used. And it can affect measurement results.
Personally I prefer to see something as below, the Pro Plus powered by an LPS and with the scaler, so high impedance input is used:

View attachment 9051


As I am still suspicious, I made another test with the LPF (which I use for class D amps measurements) attached. The scaler is used again:

View attachment 9052

Noise pollution is highly attenuated, so maybe it comes from the high frequency noise made by the PSU. I looked at the spectrum of white noise to verify how the DAC filter (there are 7 of them BTW) handles is. Below a comparison with the Pro Plus:

View attachment 9053

It doesn't look good to me.




And something for those sinad addicted, with an LPF:

View attachment 9065

and without it:

View attachment 9066

will you continue your technical review of your ultra "pcb2"?
;-)

 

[onlyoneme]

Of course, but as I said, it will be a long time process. I hope that I will add something during this weekend.

 

[canard]

Of course, but as I said, it will be a long time process. I hope that I will add something during this weekend.

I know very well that even without being ultra slick on the presentation side.. with your very exhaustive and rigorous approach, between observations of the various inputs outputs etc. it is quite huge...
the num output seems ok..
the ana output has a problem.. (it is no longer in the data announced by wiim, for those who don't want to understand-see)

will be curious to know if the power supply problem also impacts the ana inputs

;-)

 

[onlyoneme]

Some measurements added.

 

[adias]

Some measurements added.

Where have you posted those?

 

[onlyoneme]

Where have you posted those?

At the end of the main post.

 

[steadyshot]

At the end of the main post.

Do you know if the device you test which is pre production differs in any way from the one currently sold?

 

[onlyoneme]

Do you know if the device you test which is pre production differs in any way from the one currently sold?

I don't know, I assume that there are no differences.

 

[canard]

childish excitement and ostrich politics are somewhat surprising.....

 

[steadyshot]

childish excitement and ostrich politics are somewhat surprising.....

?

 

[Smartplug]

?

This what I’m talking about. It’s very difficult to understand what he was saying.