Wiim Pro Measurements - the horror, the horror + crazed fanboi

Discussion in 'Source Measurements' started by purr1n, Jun 2, 2025.

  1. purr1n

    purr1n Desire for betterer is endless.

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    So Lindsay and I did a video a while back about how horrible the Wiim Pro sounded here: https://www.superbestaudiofriends.org/index.php?threads/wiim-pro-streamer-review.14835/

    with the video here:


    If I could ask a favor from this community, please go the video and hit like / thumbs up. This is to provide balance to the Force. That is our least popular video and I know YT will punish it for not being liked. The wanted to try out the Wiim because it seemed awfully popular and many readers here asked for us to give our opinion. Well, we did, and the Wiim fanboys did not like it. From our perspective, our listening to it and crapping on it was a service to the audiophile community. The Wiim Pro's SPDIF coaxial output just sucked subjectively speaking. Since then, we've gotten hate, but also comments from others that the certain DACs had trouble locking into the Wiim Pro's SPDIF output. I decided to check out some measurements - the SPDIF output measurements.

    Below is the SPDIF output. Unfortunately I forgot to grab the zoomed in square wave. After all, a bunch of square waves at 44.1kHz (or 48kHz, or whatever the sampling rate) is what the output is supposed to look like. Below is are square waves squished tightly together but zoomed out.

    PXL_20250325_175107741_corrected.jpeg

    So what's the issue? The square waves are riding on top on another frequency! 60Hz and some harmonics to be precise! Not only that, the 60Hz harmonics is MASSIVE!

    Give that the spec for the output level of SPDIF is supposed to be 0.5V peak to peak at most, no wonder some DACs can't lock on to the Wiim Pro's output. I bet many receivers are misinterpreting the Wiim Pro's SPDIF output because the 60Hz (+ harmonics) is "flipping" the bits!
     
  2. purr1n

    purr1n Desire for betterer is endless.

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    So I plugged the SPDIF output into the analog input of the APx555 analyzer and set the bandwidth to 1MHz. This still isn't enough to make out the square waves, but at least we can analyze the noise spectrum better.

    So what I found out is that the SPDIF output of the Wiim Pro was highly dependent upon the USB power plug. This was the worst example - using an Apple one. The noise, kind of a triangle wave at 60Hz, is almost 1Vpp!

    PXL_20250325_173605883_corrected - Copy.jpg
     
    Last edited: Jun 2, 2025
  3. purr1n

    purr1n Desire for betterer is endless.

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    This next one is better, it was a cheapo charger I found somewhere, probably from Amazon. Still about 300mVpp, not good because it's enough to trigger the bit flips in an SPDIF output.

    PXL_20250325_174143876_corrected.jpeg

    Here is another one, but with music playing. The line is thicker because there are varying square waves (again can't be seen on the APx555 - we need a scope) embedded in the triangular 60Hz "carrier".

    PXL_20250325_172359051_corrected.jpeg
     
  4. purr1n

    purr1n Desire for betterer is endless.

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    Finally, what is a decent SPDIF output supposed to look like? You can plug in almost any decent digital source, and the output is gonna look like this.

    PXL_20250325_174844585.jpg

    Yeah.

    --

    Wiim Pro: the horror, the horror

    Again, please go the video and click like on it. Don't let shills leverage YT to promote crappy products that both sound horrible and measure horribly. And yes, the company behind the Wiim knows how to play that game. And where is audio science when we really need it?

    P.S. We tested two different units. Same result.
     
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    Last edited: Jun 2, 2025
  5. crazychile

    crazychile Eastern Iowa's Spiciest Pepper

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    Would the Wiim Ultra be much better? It doesnt use a USB C power supply, and maybe running the USB out to an input on URD before a DAC might improve things. I'm kind of done with Pi based stuff because I want a better GUI and still want to keep it really easy. I love the Wiim convenience, but not what I've heard so far.
     
  6. Ash1412

    Ash1412 Friend

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  7. atomicbob

    atomicbob dScope Yoda

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    Those are horrible results from the Wiim Pro.
    Would it be possible to send me one for analysis?

    Third post of this measurement series has results for several USB power warts inluding an Apple for an older iPad.
     
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  8. Clemmaster

    Clemmaster Friend

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    I thought the Apple chargers were actually as good as mass-market chargers went?
    Why would there be so much 60Hz leakage in an SMPS anyway?
     
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  9. ADias

    ADias New

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    The Ultra I use is connected via USB to Urd Unison and is indistinguishable from an iPad USB-c also connected to the Urd. The iPad is in Airport/WiFi mode and solely streams Qobuz. The Urd Unison output is connected to Yggdrasil+ OG Unison.

    I also have a Pro connected via SPDIF/coax and hear no ill effects. I considered Pi-streamers and others and see no gain. WiiM offers Qobuz Connect and Googlecast - very convenient and it works just fine.

    edit: airport mode
     
    Last edited: Jun 2, 2025
  10. crazychile

    crazychile Eastern Iowa's Spiciest Pepper

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    I may try an iPad again to see how it compares. I used an iPad as a source several years back and it seemed like the Pi2AES was a pretty big jump up in sound quality when I swapped it out.
     
  11. purr1n

    purr1n Desire for betterer is endless.

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    Yes. I can send you one. Going on vacation, but will send in two weeks.
     
  12. bixby

    bixby Friend

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    I always suspected the hype of Wiim to be unwarranted. Isn't Harmon aka Samsung behind the brand?

    Reminds me of some lower level hype around Fosi and Topping a few years back. My experiences with both were pretty poor just based on function and what I heard.

    I will schedule a time to watch your video, could be fun!

    Enjoy some downtime!
     
  13. Baten

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    I have a older WiiM non-pro. These results are pretty damn bad. Maybe I should stop postponing to replace it o_O
     
  14. Thad E Ginathom

    Thad E Ginathom Friend

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    I know nothing about this WiiM but... a streamer is basically a PC dressed in hifi clothes, right? Runs Linux? Could it be that they screwed up the software and there are all sorts of interrupts jumping up and down messing with the audio?
     
  15. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    For what it's worth here is the jitter plot for the Wiim Pro using an APX555:
    wiim_pro_plus_jitter_192Khz_24bit_test_file.PNG

    Mercury V3 for comparison (RCA, same as Wiim):
    mercury_v3_bnc_linear_jitter.PNG

    Let's hope they don't sue me! :eek:
     
  16. SofaSamuraiX

    SofaSamuraiX Almost "Made"

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    Are these devices comparable in price, I don't doubt your product could be made to a higher standard. Just wondering if a device made for real "hi-fi" nerds is in the same class.
    Edited to say: I answered my own question with a Google search...
     
    Last edited: Jun 3, 2025
  17. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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  18. onlyoneme

    onlyoneme Wiim Beta Tester

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    What about impedances?
    75 ohm termination

    [​IMG]

    no termination

    [​IMG]
     
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  19. ADias

    ADias New

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    That is quite a turn of events.
     
  20. purr1n

    purr1n Desire for betterer is endless.

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    Can you elaborate more as opposed to being cryptic with respect to the 75-ohm termination?

    I used this cable with characteristic impedance of 75-ohms terminated BNC (measurement gear) and RCA (Wiim SPDIF output): https://benchmarkmedia.com/products/benchmark-bnc-to-rca-coaxial-cable-digital

    Are you suggesting I should try another coaxial cable with RCA on both ends and cap it off with a 75-ohm BNC terminator such as this: https://www.sweetwater.com/store/detail/BNCTerm--pro-co-75-ohm-bnc-terminator

    With the 75-ohm termination, did you attempt to try with a DAC to compare subjectively audio quality? The Wiim Pro manual didn't mention anything of this sort so I am not sure what you did. I would like to see if I can duplicate your findings.

    ---

    Also, please introduce yourself as this is your first post:

    https://www.superbestaudiofriends.org/index.php?threads/new-members-introduce-yourself.11639/
     
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    Last edited: Jun 3, 2025

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