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:
![1720769403786.png 1720769403786.png](https://forum.wiimhome.com/data/attachments/8/8954-20cc37f272ec07e4c04154c57769e1fd.jpg)
And this is for the Pro/Plus:
![1720769474185.png 1720769474185.png](https://forum.wiimhome.com/data/attachments/8/8955-8db054d055b60580038fd6888ef16130.jpg)
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.
![1720790539190.png 1720790539190.png](https://forum.wiimhome.com/data/attachments/8/8971-7d7c00c86db059e6ce12396e7ffd4eab.jpg)
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:
![1720903066613.png 1720903066613.png](https://forum.wiimhome.com/data/attachments/9/9045-bde9b4f0da3d93e8c90bcea255bfaa92.jpg)
and with the screen on:
![1720903180297.png 1720903180297.png](https://forum.wiimhome.com/data/attachments/9/9046-cb175960e38e2ac92e75be0cbf92f0ea.jpg)
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:
![1720903510845.png 1720903510845.png](https://forum.wiimhome.com/data/attachments/9/9047-95dd3663be5184e941d8ccd9255a013d.jpg)
and the screen on:
![1720903589841.png 1720903589841.png](https://forum.wiimhome.com/data/attachments/9/9048-8f2fd85fc4a503c212096f59961e7a1d.jpg)
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:
![1720904460162.png 1720904460162.png](https://forum.wiimhome.com/data/attachments/9/9051-a090dcc6526c15eb0ac8050fb1beb90f.jpg)
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:
![1720904708096.png 1720904708096.png](https://forum.wiimhome.com/data/attachments/9/9052-59b3410bd3afbf950e661ec8e5022d9b.jpg)
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:
![1720905256950.png 1720905256950.png](https://forum.wiimhome.com/data/attachments/9/9053-109aae7d68274e9dae49ad75f8bbebd8.jpg)
It doesn't look good to me.
And something for those sinad addicted, with an LPF:
![1720974561375.png 1720974561375.png](https://forum.wiimhome.com/data/attachments/9/9065-cde53ca70c5880ce11786bb2c1c49d12.jpg)
and without it:
![1720974585447.png 1720974585447.png](https://forum.wiimhome.com/data/attachments/9/9066-909278abb32b88deb57f38e126e9b607.jpg)
For all the following tests I will use the LPF, except stated otherwise.
The Dynamic Range, 120.1 dB.
![1721577342499.png 1721577342499.png](https://forum.wiimhome.com/data/attachments/9/9361-acb5c27520d020ed339e52c5e36ab764.jpg)
THD vs level, for 1 kHz test tone:
![1721593892080.png 1721593892080.png](https://forum.wiimhome.com/data/attachments/9/9375-8dd121d67d38b7b91316e2d8cea5966e.jpg)
IMD vs level, for SMPTE test tone:
![1721594003400.png 1721594003400.png](https://forum.wiimhome.com/data/attachments/9/9376-62fafedbbcb626c92b3e89f584e9968f.jpg)
A small sign of ESS hump is visible. I said in the comments, based on quick tests, that it wasn't visible with the LPF, but I was wrong.
J-test for the analog output. I've no idea why some people take such results as jitter measurements of the digital outputs...
![1721594702762.png 1721594702762.png](https://forum.wiimhome.com/data/attachments/9/9377-12bed837ee853d3849b77144cc47d77b.jpg)
NID multitone:
![1721594859378.png 1721594859378.png](https://forum.wiimhome.com/data/attachments/9/9378-a53cf19d40cffcc1cdb759c6feef1125.jpg)
Time for something I would call a noise profile, over the coaxial output. I use both ADC Cosmos and the Scaler plus the LPF, with a termination at 75 ohm just before the LPF. Due to the LPF characteristics I limit the recording sample rate to 96 kHz. As a test signal I use dithered "silence" file.
First result comes from SMSL PO100 Pro, powered by the USB hub:
![1721753711171.png 1721753711171.png](https://forum.wiimhome.com/data/attachments/9/9443-b54a68975097ef29991e27f74bb357b2.jpg)
Next one is the WiiM Pro, powered by Sbooster LPS:
![1721753762455.png 1721753762455.png](https://forum.wiimhome.com/data/attachments/9/9444-77c783e2514d6768111b37b015a7eac3.jpg)
And the last one is the Ultra, powered by its internal SMPS:
![1721753830616.png 1721753830616.png](https://forum.wiimhome.com/data/attachments/9/9445-3d62b3c6a6ab68aa37a4ead661a45d73.jpg)
Low-level -90.31 dB signals look worse then for the Pro Plus.
Undithered, 16 bit:
![1722008690629.png 1722008690629.png](https://forum.wiimhome.com/data/attachments/9/9560-9f48dbbcb25a34820943debc0ee2b74b.jpg)
The same but 24 bit:
![1722008741897.png 1722008741897.png](https://forum.wiimhome.com/data/attachments/9/9561-2df9c1c8557edc8fd879dc085d2bb97f.jpg)
Even the LPF doesn't let reach the Pro Plus level, although without it results are much worse.
The same signals but for the Pro Plus:
![1722008891130.png 1722008891130.png](https://forum.wiimhome.com/data/attachments/9/9562-40878a069b05c7a74c17ec5c3367fe6b.jpg)
![1722008926746.png 1722008926746.png](https://forum.wiimhome.com/data/attachments/9/9563-9d3f67d99a4729dc7b2ec2a1b017c011.jpg)
Intersample peaks are handled well, no LPF this time.
![1722010633646.png 1722010633646.png](https://forum.wiimhome.com/data/attachments/9/9565-7f5ae3265f4f5752de16f3df6cdd8e40.jpg)
Even peaks at +3 dBFS do not result in clipping, there is enough analog headroom to handle it.
The latest firmware promises jitter improvements. And it improved indeed (j-test for the previous FW can be seen somewhere above in this post):
![1722272950905.png 1722272950905.png](https://forum.wiimhome.com/data/attachments/9/9622-252cc070269987f0e228d28d6ad721f7.jpg)
A progress is visible also for 1 kHz test tone (graph with the previous FW was shown for the sinad measurement somewhere above):
![1722273565853.png 1722273565853.png](https://forum.wiimhome.com/data/attachments/9/9623-80f3ff957f7d6a3a2788142cca4974a3.jpg)
Well done @WiiM Team @WiiM Support .
Let's talk about the jitter over digital outputs. I will use the Holo Audio Spring 3 DAC which is a true NOS DAC and has an unique ability to turn off its PLL. This way I can compare a raw performance of the outputs in j-test.
Toslink:
![1722427396645.png 1722427396645.png](https://forum.wiimhome.com/data/attachments/9/9674-a37c7d3d5a86a13fefd07b97f59891ab.jpg)
Coax:
![1722427452900.png 1722427452900.png](https://forum.wiimhome.com/data/attachments/9/9676-bf5f1bf1decd8011b16a0eabe775e20c.jpg)
Toslink is better in case of the Ultra.
And USB which is unfair for the comparison of course, because it's clocked by the DAC:
![1722427529026.png 1722427529026.png](https://forum.wiimhome.com/data/attachments/9/9677-8c8f20533394d401b211084d77938525.jpg)
Spring 3 has incredibly low jitter.
All 3 graphs on the same screen:
![1722428195077.png 1722428195077.png](https://forum.wiimhome.com/data/attachments/9/9681-5cf49c11eb123a277699c028d52d4a89.jpg)
Let's look how the jitter suppression works. A coax output but the PLL is on:
![1722427658032.png 1722427658032.png](https://forum.wiimhome.com/data/attachments/9/9678-bd8a077b81ea27e94709ff59cdfce1c6.jpg)
The jitter suppression of Spring 3 is extremely good, as far as I know it's one of the best available on the market.
Time for a "torture" test. I will use 192 kHz j-test signal to verify if cables matter. The Holo Audio Spring 3 in action again, PLL is off.
Mogami 2964:
![1722592786064.png 1722592786064.png](https://forum.wiimhome.com/data/attachments/9/9778-724edbaaac3042418e6a0a6fb8ca1fd0.jpg)
Hosa BNC WordClock cable:
![1722592844871.png 1722592844871.png](https://forum.wiimhome.com/data/attachments/9/9779-87e15c4642b8e13f3448a8ef647b84b7.jpg)
No serious difference for these coax cables. Time for optical ones.
A random one I used for jitter tests already, but I found out it's labelled as "Bandridge":
![1722593074371.png 1722593074371.png](https://forum.wiimhome.com/data/attachments/9/9780-89985b57abb0a092f88453ee510c01d6.jpg)
WiiM cable delivered with the Ultra:
![1722593103103.png 1722593103103.png](https://forum.wiimhome.com/data/attachments/9/9781-44969238b80f4d181cdded171d5baeea.jpg)
Hosa OPM-303:
![1722593153867.png 1722593153867.png](https://forum.wiimhome.com/data/attachments/9/9782-0c52606ab613657a5f131de3279c9256.jpg)
Well, time to change my own opinion, toslink cable matters
Pity that my favorite WiiM cable is not of the best quality ![Frown :( :(](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Of course the final result depends on the DAC and its ability to suppress the jitter.
WiiM cable but PLL is on:
![1722593427493.png 1722593427493.png](https://forum.wiimhome.com/data/attachments/9/9783-cce89af852261e17830c50a75167b7c8.jpg)
And Mogami coax, PLL is on:
![1722593563882.png 1722593563882.png](https://forum.wiimhome.com/data/attachments/9/9784-78ca60de192c6bd2d131037f5ebf0885.jpg)
Results are very close when PLL is turned on.
After few listening sessions I think I could fall in love with the Ultra although these PSU noise spikes irritate me a lot.
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:
![1720769403786.png 1720769403786.png](https://forum.wiimhome.com/data/attachments/8/8954-20cc37f272ec07e4c04154c57769e1fd.jpg)
And this is for the Pro/Plus:
![1720769474185.png 1720769474185.png](https://forum.wiimhome.com/data/attachments/8/8955-8db054d055b60580038fd6888ef16130.jpg)
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.
![1720790539190.png 1720790539190.png](https://forum.wiimhome.com/data/attachments/8/8971-7d7c00c86db059e6ce12396e7ffd4eab.jpg)
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:
![1720903066613.png 1720903066613.png](https://forum.wiimhome.com/data/attachments/9/9045-bde9b4f0da3d93e8c90bcea255bfaa92.jpg)
and with the screen on:
![1720903180297.png 1720903180297.png](https://forum.wiimhome.com/data/attachments/9/9046-cb175960e38e2ac92e75be0cbf92f0ea.jpg)
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:
![1720903510845.png 1720903510845.png](https://forum.wiimhome.com/data/attachments/9/9047-95dd3663be5184e941d8ccd9255a013d.jpg)
and the screen on:
![1720903589841.png 1720903589841.png](https://forum.wiimhome.com/data/attachments/9/9048-8f2fd85fc4a503c212096f59961e7a1d.jpg)
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:
![1720904460162.png 1720904460162.png](https://forum.wiimhome.com/data/attachments/9/9051-a090dcc6526c15eb0ac8050fb1beb90f.jpg)
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:
![1720904708096.png 1720904708096.png](https://forum.wiimhome.com/data/attachments/9/9052-59b3410bd3afbf950e661ec8e5022d9b.jpg)
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:
![1720905256950.png 1720905256950.png](https://forum.wiimhome.com/data/attachments/9/9053-109aae7d68274e9dae49ad75f8bbebd8.jpg)
It doesn't look good to me.
And something for those sinad addicted, with an LPF:
![1720974561375.png 1720974561375.png](https://forum.wiimhome.com/data/attachments/9/9065-cde53ca70c5880ce11786bb2c1c49d12.jpg)
and without it:
![1720974585447.png 1720974585447.png](https://forum.wiimhome.com/data/attachments/9/9066-909278abb32b88deb57f38e126e9b607.jpg)
For all the following tests I will use the LPF, except stated otherwise.
The Dynamic Range, 120.1 dB.
![1721577342499.png 1721577342499.png](https://forum.wiimhome.com/data/attachments/9/9361-acb5c27520d020ed339e52c5e36ab764.jpg)
THD vs level, for 1 kHz test tone:
![1721593892080.png 1721593892080.png](https://forum.wiimhome.com/data/attachments/9/9375-8dd121d67d38b7b91316e2d8cea5966e.jpg)
IMD vs level, for SMPTE test tone:
![1721594003400.png 1721594003400.png](https://forum.wiimhome.com/data/attachments/9/9376-62fafedbbcb626c92b3e89f584e9968f.jpg)
A small sign of ESS hump is visible. I said in the comments, based on quick tests, that it wasn't visible with the LPF, but I was wrong.
J-test for the analog output. I've no idea why some people take such results as jitter measurements of the digital outputs...
![1721594702762.png 1721594702762.png](https://forum.wiimhome.com/data/attachments/9/9377-12bed837ee853d3849b77144cc47d77b.jpg)
NID multitone:
![1721594859378.png 1721594859378.png](https://forum.wiimhome.com/data/attachments/9/9378-a53cf19d40cffcc1cdb759c6feef1125.jpg)
Time for something I would call a noise profile, over the coaxial output. I use both ADC Cosmos and the Scaler plus the LPF, with a termination at 75 ohm just before the LPF. Due to the LPF characteristics I limit the recording sample rate to 96 kHz. As a test signal I use dithered "silence" file.
First result comes from SMSL PO100 Pro, powered by the USB hub:
![1721753711171.png 1721753711171.png](https://forum.wiimhome.com/data/attachments/9/9443-b54a68975097ef29991e27f74bb357b2.jpg)
Next one is the WiiM Pro, powered by Sbooster LPS:
![1721753762455.png 1721753762455.png](https://forum.wiimhome.com/data/attachments/9/9444-77c783e2514d6768111b37b015a7eac3.jpg)
And the last one is the Ultra, powered by its internal SMPS:
![1721753830616.png 1721753830616.png](https://forum.wiimhome.com/data/attachments/9/9445-3d62b3c6a6ab68aa37a4ead661a45d73.jpg)
Low-level -90.31 dB signals look worse then for the Pro Plus.
Undithered, 16 bit:
![1722008690629.png 1722008690629.png](https://forum.wiimhome.com/data/attachments/9/9560-9f48dbbcb25a34820943debc0ee2b74b.jpg)
The same but 24 bit:
![1722008741897.png 1722008741897.png](https://forum.wiimhome.com/data/attachments/9/9561-2df9c1c8557edc8fd879dc085d2bb97f.jpg)
Even the LPF doesn't let reach the Pro Plus level, although without it results are much worse.
The same signals but for the Pro Plus:
![1722008891130.png 1722008891130.png](https://forum.wiimhome.com/data/attachments/9/9562-40878a069b05c7a74c17ec5c3367fe6b.jpg)
![1722008926746.png 1722008926746.png](https://forum.wiimhome.com/data/attachments/9/9563-9d3f67d99a4729dc7b2ec2a1b017c011.jpg)
Intersample peaks are handled well, no LPF this time.
![1722010633646.png 1722010633646.png](https://forum.wiimhome.com/data/attachments/9/9565-7f5ae3265f4f5752de16f3df6cdd8e40.jpg)
Even peaks at +3 dBFS do not result in clipping, there is enough analog headroom to handle it.
The latest firmware promises jitter improvements. And it improved indeed (j-test for the previous FW can be seen somewhere above in this post):
![1722272950905.png 1722272950905.png](https://forum.wiimhome.com/data/attachments/9/9622-252cc070269987f0e228d28d6ad721f7.jpg)
A progress is visible also for 1 kHz test tone (graph with the previous FW was shown for the sinad measurement somewhere above):
![1722273565853.png 1722273565853.png](https://forum.wiimhome.com/data/attachments/9/9623-80f3ff957f7d6a3a2788142cca4974a3.jpg)
Well done @WiiM Team @WiiM Support .
Let's talk about the jitter over digital outputs. I will use the Holo Audio Spring 3 DAC which is a true NOS DAC and has an unique ability to turn off its PLL. This way I can compare a raw performance of the outputs in j-test.
Toslink:
![1722427396645.png 1722427396645.png](https://forum.wiimhome.com/data/attachments/9/9674-a37c7d3d5a86a13fefd07b97f59891ab.jpg)
Coax:
![1722427452900.png 1722427452900.png](https://forum.wiimhome.com/data/attachments/9/9676-bf5f1bf1decd8011b16a0eabe775e20c.jpg)
Toslink is better in case of the Ultra.
And USB which is unfair for the comparison of course, because it's clocked by the DAC:
![1722427529026.png 1722427529026.png](https://forum.wiimhome.com/data/attachments/9/9677-8c8f20533394d401b211084d77938525.jpg)
Spring 3 has incredibly low jitter.
All 3 graphs on the same screen:
![1722428195077.png 1722428195077.png](https://forum.wiimhome.com/data/attachments/9/9681-5cf49c11eb123a277699c028d52d4a89.jpg)
Let's look how the jitter suppression works. A coax output but the PLL is on:
![1722427658032.png 1722427658032.png](https://forum.wiimhome.com/data/attachments/9/9678-bd8a077b81ea27e94709ff59cdfce1c6.jpg)
The jitter suppression of Spring 3 is extremely good, as far as I know it's one of the best available on the market.
Time for a "torture" test. I will use 192 kHz j-test signal to verify if cables matter. The Holo Audio Spring 3 in action again, PLL is off.
Mogami 2964:
![1722592786064.png 1722592786064.png](https://forum.wiimhome.com/data/attachments/9/9778-724edbaaac3042418e6a0a6fb8ca1fd0.jpg)
Hosa BNC WordClock cable:
![1722592844871.png 1722592844871.png](https://forum.wiimhome.com/data/attachments/9/9779-87e15c4642b8e13f3448a8ef647b84b7.jpg)
No serious difference for these coax cables. Time for optical ones.
A random one I used for jitter tests already, but I found out it's labelled as "Bandridge":
![1722593074371.png 1722593074371.png](https://forum.wiimhome.com/data/attachments/9/9780-89985b57abb0a092f88453ee510c01d6.jpg)
WiiM cable delivered with the Ultra:
![1722593103103.png 1722593103103.png](https://forum.wiimhome.com/data/attachments/9/9781-44969238b80f4d181cdded171d5baeea.jpg)
Hosa OPM-303:
![1722593153867.png 1722593153867.png](https://forum.wiimhome.com/data/attachments/9/9782-0c52606ab613657a5f131de3279c9256.jpg)
Well, time to change my own opinion, toslink cable matters
Of course the final result depends on the DAC and its ability to suppress the jitter.
WiiM cable but PLL is on:
![1722593427493.png 1722593427493.png](https://forum.wiimhome.com/data/attachments/9/9783-cce89af852261e17830c50a75167b7c8.jpg)
And Mogami coax, PLL is on:
![1722593563882.png 1722593563882.png](https://forum.wiimhome.com/data/attachments/9/9784-78ca60de192c6bd2d131037f5ebf0885.jpg)
Results are very close when PLL is turned on.
After few listening sessions I think I could fall in love with the Ultra although these PSU noise spikes irritate me a lot.
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