Choosing the Right WiiM Streamer for a High-End External DSP System (Pro vs. Pro Plus vs. Ultra)

[etemkin]

tl;dr: I'm feeding a miniDSP Flex HT via Toslink for all processing, so the WiiM's DAC and analog outs won't be used. Is there any reason (better clocking, cleaner digital signal, etc.) that the Pro Plus or Ultra would perform better as a pure transport than the standard WiiM Pro in a high-end system?

Hi everyone,

I'm in the late stages of designing a new audio system and have decided on a WiiM streamer to act as my dedicated music transport. I've done a lot of reading and I'm leaning towards the WiiM Pro, but before I pull the trigger, I wanted to tap into the community's expertise to make sure I'm not missing a key feature or performance benefit of the Pro Plus or the Ultra.

My primary goal is to get the purest possible digital signal to my external processor (miniDSP Flex HT). The WiiM's internal DAC and analog outputs will not be used.

Here is a quick overview of the planned system:

• Processor/DAC: The WiiM will send a digital signal to a miniDSP Flex HT. This unit will handle all D/A conversion, active crossovers, and room correction via Dirac Live.
• Amplifier: Buckeye Amps 3-Channel (Hypex or Purifi -- TBD).
• Speakers: B&W CM9 S2 (L/R) and a matching CM Centre 2 S2.
• Subwoofers: A pair of high-performance subs (likely Rythmik FVX12s/Hsu VTF-TN1/RSL Speedwoofer 12S or similar).

My logic is that since the WiiM Pro will only be acting as a digital transport, the primary advantages of the Pro Plus (better DAC, better analog stage) and the Ultra (better DAC, room correction, extra inputs) are redundant in my system (I don't plan to use the analog inputs).

With that in mind, I have a few specific questions for the experts here:

1. Bit-Perfect Transport: Is there any reason to believe that the Pro Plus or the Ultra would deliver a cleaner or "more" bit-perfect digital signal to the miniDSP than the standard Pro? Does their internal architecture, power supply, or clocking offer any tangible benefit when used purely as a transport? I plan to mostly stream high-quality audio from Tidal if that's relevant.
2. Connections: My plan is to connect the WiiM to the miniDSP via Toslink (Optical) for electrical isolation. Are there any advantages to the connections on the Pro Plus or Ultra (namely USB) in this context?
3. Room Correction: I know the Ultra has its own room correction feature. Does this offer any benefits in conjunction with or over a full Dirac Live calibration performed by the miniDSP? Or is it completely bypassed when sending a digital signal out?
4. Anything I'm Missing? Is there any other subtle feature, performance benefit, or quality-of-life improvement in the Pro Plus or Ultra that I might be overlooking for a transport-only application in a highly resolving system like this? There's obviously the screen with the Ultra, but if the sound quality is the same, not sure that alone is worth it to me.

I want to make sure I'm making the smartest "no compromise" choice that aligns with the rest of my components.

Thanks in advance for sharing your knowledge and experience! Happy to provide any more details if that would be useful.

 

[Valentino]

Short answer: The Pro will do if you don’t use analog I/O.

My system is similar to yours (WiiM feeding MiniDSP Flex Eight optically), but I like a volume wheel and level readout on the box itself. There’s also an analog headphone amp in my system, and I use a MiniDSP Adept as analog front end for my turntable and SACD player, connected to the optical input of (you will have guessed it) my WiiM Ultra. System description in my profile.

 

[etemkin]

Interesting -- thanks, Valentino! I asked a similar question to miniDSP support and they responded with "We examined the WiiM ultra USB output, and it can connect with our Flex HT (UAC2.0 compliant), which would allow Tidal audio via the USB output to achieve a higher resolution compared to the Toslink input. ( The quality of the cables can variate the sound quality )"

Since you have the Ultra, have you tried comparing USB output v. Toslink? If so, notice any difference?

Much appreciated!

 

[Mr Ee]

All the wiims can output 192khz over toslink, but yes, some have reported issues with some optical cables at that frequency.
Few (if any?) have reported such issues with the wiim supplied optical cable, it seems to be mostly expensive, audiophile cables being reported!
I don't know if the Flex limits optical input to 96khz; from their comment about cables it seems maybe not.
This is a question / answer about the wiim Ultra that may be of interest to you.


[td width="305px"]Are there any improvements to the streamer circuit that would improve sound quality? I.e. if we are using this purely as a streamer connected to a high-end external DAC (so not using volume control, room correction sub out etc), are there any improvements in streaming section to deliver higher quality sound vs Pro Plus?[/td][td width="342px"]The digital output is transparent, comparable to the Pro Plus but with improved jitter performance.[/td]

Edit: the above looked good when I copy/pasted it, but not so good after posting!
But you can still read it, so...


Whether it makes any tangible difference I can't say.
Well I can - for me personally I couldn't tell any difference between a mini, a pro and an ultra all optical out to my headphone setup when i tried it a year or so ago.

The wiim digital output is affected by any EQ etc. you apply in the wiim app, but presumably you'd be doing all that in your DSP instead.