WiiM Ultra: who has it and who has already opened it?

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#22
jimk04 said:
So having a few weeks with the Wiim Ultra I have to say I am very impressed and pleased. It has tonnes more features than I was aware of. Plus points for me;
1. It just works, always, and seamlessly. Something my Volumio Rpi didn't. To say the least! Whether streaming or then switching to hdmi ARC ( which I'm new to!...more on that later) for TV playback.
2. The Tidal and Spotify casting works very well.
3. It has native links for Radio Paradise and BBC Radio channels. I thought the Beeb had managed to preclude third parties from doing this. So whilst it remains, it's a bonus.
4.Room correction which uses your mobile phone mic to setup, can also use a proper USB mic plugged into your phone. Very clever and has really improved my SQ. You can fine tune the curves/correction it creates. And can save different EQs for different inputs .
5. Subwoofer output with control, can alter the cut off from 60 to mid 200s, and you can dictate whether it HPs your mains or not. Is included in the EQ. All the EQ comes out of all the outputs, not just the analog RCAs.
6.Probably more that I can't recall at the moment !

SQ through the onboard ESS dac is very listenable if not just plain very good. I almost see no reason to bother with an external DAC. But this is DIY, so I've ordered the Xingcore U30 USB I2S board to be able to feed my AD1862/FIFO set up with usb digital from the Ultra. Will be an interesting comparison.
I've been planning a semi active setup and have some active XOs at the ready but not implemented yet. The SW output now makes me rethink, but it is just a single mono. I'm wondering if I split with into 2 with a simple 'Y' and then buffer it, it would be ok into 2 channels?

The screen is small but large enough to get the jist of the album art from 2.5m. The app is very nicely done. The packaging it comes in is up there with Dyson/Apple products, if that sort of thing floats your boat. And it comes with all the cables you could need to send the signal in and out. ...actually maybe not a USB out.

Edit..more on the HDMI ARC. I am into my picture quality aswell and I had my Sky Q box into my 4k TV into the HDMI ARC port of the TV. When I got the Wiim , not really knowing what ARC is, thought I'd better put the Ultra into the ARC socket, and so moved the Sky into a 'normal' hdmi socket. Well it seems to have improved the PQ quite a bit. Don't know why!
Click to expand...
I have the Ultra and the inbuilt dac has a very low output impedance that really should be higher than 11 Ohms. 100 -200 Ohm would be about optimal with most cables . One can probably tailor the sound a bit playing with the output impedance , higher, like 1 Kohm or more will sound ”nicer” . Easily done using two resistors is series with + and solder them inside the RCA connectors of the cable.

The Ultra has 4 IC:s after the dac . As Audio2g shows in their video, It uses 4 opa1611, a very good choice for IV and output buffers.
Its hard to justify any modifications when the DAC has a SINAD or 115 dB as it is ( verified at audiosciencereview ). But one might want to make the sound more ”analog”.

The default digital filter in the ultra is a conventional steep one . Changing that to other options will change the sound a la Marantz or Linn klimax DS (v.1)
Try Minimum phase, fast rolloff. The SINAD will be worse with such a filter, but the sound will be more ”vivid”.

Here is a good link of some external mods of the ultra, changing the sound:

https://forum.wiimhome.com/threads/making-the-ultra-more-”-musical-”-easy-external-diy.4512/
 
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#23
jean-paul said:
As the thread title. Not too fond of the previous models as these did not have USB ports but this one has. So I am curious how it looks and how it performs especially via USB. The reviews are raving but maybe we should take those with a grain of salt 🙂
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I would really like to know at what voltage the opa1611 are fed, and the values of the resistors from regulators to +V pin input of the opa1611. In some Marantz CD players, they use resistors with higher values than the usual 10 ohms, some have 100 ohms making the sound warmer and more ”analog ”.

In worse case scenario for sound quality , the Ultra may use the regulators directly coupled to the Opa:s without resistors before the + V . A more unstiff powersupply using high value resistors may get higher scores at soundquality.

I dont know anything of how the powersupply are connected to the dac part of the ultra , because I havent opened up the unit yet. So , please post here if anyone has done it already.

Regarding the USB - You can connect a 3 TB SSD directly to the Ultra because it can provide 5V 1.7 A . This is in my opinion the best thing with the Ultra, apart from the room correction option.

I think that the electrical spdif are the best sounding option of the Ultra to an external dac. The usb has asyncron output so it might be a technically better solution with the right dac.
 
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#24
Not sure if changing the sound is necessary but having the normal stop resistor in the output (cable capacitance) of 47 to 100 Ohm is not much work.

Pictures of the innards would help a lot. I thought to buy an Ultra just for fun, we'll see.

Audientid14, the SSD is connected via USB I think? Eversolo DMP-A6 has it internally which is even nicer. Again an external DAC is the least what one would want really.
 
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#26
That is good to hear. If an external DAC is necessary I would not buy/keep it. Yet another device that needs a fifth wheel. If only to avoid yet another terrible DAC thread here 🙂 Some more strictness can be maintained by having the criterium a device should be very good as it is. Changing sound by unstiffening supply lines whould not be my way of working. That is effect generator territory. The usual way is to check decoupling, regulators, shielding but the Ultra's numbers are so good it possibly will deteriorate by intervention. However ES9038 is known for sometimes unpleasant sound which seems to be IN the IC and unsolvable by us mortal souls (maybe the DAC Meisters have a method). Pity. ES9039 probably would have been a better choice. Maybe in a next revision? I think I will wait for that. Eversolo DMP-A6 also has ES9038 (2 even) and it improves with external transformers too. Summed up I want neither an external DAC nor transformers added to improve on ES9038 but that may be your choice. All good.

Lacking stop resistors (if really so) can even possibly be enough. Someone unsatisfied should open it to verify.
 
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#27
I'm pretty happy with the sound. I will rebuild my Miro AD1862 dac soon with the Xing core U30 USB to I2S module so I can feed it USB from the Ultra, but until then I can't really comment on SQ comparisons. Safe to say the Ultra is perfectly adequate to my ears. I don't tend to hear the ESS 'thing' indeed I had one of Ian Canada's implementations of them and found it very good, albeit it with loads of PSU rails and transformer IV.
 
#28
You could skip USB to I2S alltogether if the Ultra has I2S internally. Conversion of I2S to USB and from USB to i2S again seems counterproductive. If it is adequate and you're already quite happy with the sound any endeavor with multiple conversions seems futile and likely unsuccessful. The 2 resistors seem a no time small job that may have the desired result.

Pity as I do hear the ES9038 thingie and not just in 1 device. Now it seems not to be there in ES9039 (it does not seem to occur in ES9023, ES9033Q) but how many audio players and DACs does one have to buy? On the other hand I would have to have Ultra here to see if it exhibits the phenomenon instead of stupid assuming.
 
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#30
Opening it is not hard. It is the thinking, analysis and see possible imperfections and the improvements IF these are needed. We are not in the stone ages anymore and even ES9038 is already acceptable to most I guess. It is close to nitpicking (maybe).

Probably the only useful things that can be done are in the PSU and analog section. Again, assumptions don't do good and opening and analysis if only out of pure technical interest is the way. The people at WiiM are surely competent in a few areas and their success is only good for us.
 
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#34
jean-paul said:
Thanks a lot! Posted 30th of september but I missed it. Not a daily ASR visitor. Looks to be built good. Only detail I notice at first glance are the not high quality SMD electrolytic caps. And it has PCM5121 besides ES9038. Will study it tonight.
Click to expand...
PCM5121 is only for the subwoofer output.
Is there maybe a point were you can steal the signal coming from the ESS dac , right after the first opa1611 ?
Maybe skip the buffer, taking the signal right after IV conversion , steal it directly from the + output of the two first opa1611 and send it through two 2,2 uF polycaps and two 100 ohm resistors and then directly to the RCA+ connector ? Bypassing any muting circuits….

Now, there is a modification of the psu from Teddy pardo out there to .
 
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#36
I currently using a MacBook Pro usb out to marcel RTZ FIRDAC mainly streaming Amazon prime unlimited . Im looking at these various streamers , they look a better option than a MacBook/laptop . I’d probably use the usb out but also nice to have analog out as an option. The Wiim ultra and Bluesound nano look interesting just can’t decide which one . The BS nano uses ES9039
 
#37
Just seen the Teddy Psu. It would appear to be +/-12v, so maybe implementing a diy PSU wouldn't be too hard..?!

edit.....on the ASR internal pictures, you can clearly see an embedded SMPS, looks like a Meanwell IRM type thing, but it is only12vdc, so the neg rail must be created somehow.
 
#38
The onboard IRM like module is 12V 1570 mA. Single voltage. Probably the negative voltage is made with an extra switcher. The new PSU will replace both + and - 12V supplies for linear ones I guess. It says that it is not DIY which is a sign (also to steer people in the right direction).
 
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