WiiM Amp Pro Streaming Stereo Amplifier Review

[restorer-john]

It makes no sense to use every manufacture's spec. You won't be able compare one product to another then. My method expands on 1% THD (if possible) at 1 KHz to see if it holds across the full audio spectrum. By using the same method in every review, the results will be comparable to other products I test. Just because a government bureaucracy created something, it doesn't mean we should follow it like lemmings.

Wrong Amir.

The entire premise of the FTC amplifier rule and it's subsequent strengthening is so consumers can compare one product to another!! That's why it was created in the first place- to stop the deception.

You are contributing to the ongoing confusion by using 1kHz@5W as a differentiator. When are you going to actually confirm manufacturers claims within the regulations for advertising output power claims?

When are you going to call them to account? This Wiim amplifier is a screaming example and you gave it top marks.

 

[Petrushka]

Wrong Amir.

The entire premise of the FTC amplifier rule and it's subsequent strengthening is so consumers can compare one product to another!! That's why it was created in the first place- to stop the deception.

You are contributing to the ongoing confusion by using 1kHz@5W as a differentiator. When are you going to actually confirm manufacturers claims within the regulations for advertising output power claims?

When are you going to call them to account? This Wiim amplifier is a screaming example and you gave it top marks.

I don’t care about what is advertised

 

[Toroid]

Excellent performance. Whenever I have need for a 2-channel amp, can't see any reason to spend more than this, even ignoring everything else this little gem can do.

Now, Wiim, get on making a multichannel amp and/or full-fledged AVR pretty please!

I would like an atmos surround processor with 9 analog outputs for $500. Is it doable? If anyone can do it wiim can!

 

[kyuu]

There's no such thing as an "FTC-like measurment".

Uh, there is if Amir makes one.

Unfortunately, it has little value in the context of Amir's reviews or the method he uses at the moment. You either do it properly or not at all. Where's the 1hr preconditioning? Where is the confirmation of THD+N for 250mW to rated power, 20Hz-20kHz? He pulls the plug at 15kHz and it's already -70dB/0.03% at 250mW and at just 80W/4R it's -54dB/>0.3% THD! You can see how little value the headline 1kHz@5W figure has.

Where are these numbers coming from?

 

[mrick39]

This is a no go in our home due to the lack of Airplay 2. I just ordered a WiiM amp to simplify a rarely used zone system.

I wish Apple would make Apple Music available as a direct service through products other than the Apple TV. Maybe I'll try Sonos for simplicity, but for extra rooms, Airplay 2 has been ok.

Apple Music is available in the Microsoft app store.

 

[quattro98]

Apple Music is available in the Microsoft app store.

I mean as a streaming service on most home audio streamers.

 

[shuppatsu]

There's nothing here for a serious audiophile wanting to push the envelope of performance

Obviously this is far from SOTA but is it your contention that these supposed defects are audible, or do you believe that serious audiophiles should care about performance well beyond audibility? Not looking for an argument, just trying to understand the sentiment conveyed.

 

[ahofer]

What does this even mean?

Due to the 2 ohm shut down it would be silent.

 

[kyuu]

Due to the 2 ohm shut down it would be silent.

Well yes, if you own a 2 ohm speaker you should probably not use this (or a great many) amps.

 

[Hart]

Do people generally factor in price when they vote? Or is it purely performance? I think price should be a parameter, and this piece is a great bang for the buck.

 

[kyuu]

Do people generally factor in price when they vote? Or is it purely performance? I think price should be a parameter, and this piece is a great bang for the buck.

I certainly do. This level of performance for $3000? Probably more of a not terrible. This level for $380? Yeah top vote for sure.

Can't speak for everyone, of course. There are certainly some people for whom the fact that this is cheap and small is in fact a negative mark. Can't be a real amplifier if it's not big and expensive.

 

[amirm]

When are you going to actually confirm manufacturers claims within the regulations for advertising output power claims?

I didn't sign up to be the QA shop for manufactures. That's on top of vast majority of companies not providing such spec to being with.

When are you going to call them to account?

I do that in every review. Large number of tests are run which are not remotely on anything from FTC.

 

[Ralph_Cramden]

Hard to imagine anyone rating this thing "Poor", but here we are.

 

[GXAlan]

Where are these numbers coming from?

@restorer-john is looking at the top line.

So if you were saying FTC 20 Hz to 20 kHz*, you could only advertise 0.1% THD at 250mW to 15 watts.

* we only have the 15 kHz measurement, so it might even be worse at 20 kHz.

Compare that to this

Where you might be able to say that for 500 mW to 180W.

If you look at McIntosh gear, they always talk 250mW to rated output. You can also look at entry level Yamaha.

 

[NTK]

So if you were saying FTC 20 Hz to 20 kHz*, you could only advertise 0.1% THD at 250mW to 15 watts.

* we only have the 15 kHz measurement, so it might even be worse at 20 kHz.

See, this just shows how amateurish these FTC people are - specifying a THD number without even knowing they also need to specify the measurement bandwidth

 

[ryanmh1]

Uh, there is if Amir makes one.

Where are these numbers coming from?

The test results. It's actually .2% at 15kHz. Typo first from me (corrected) then John. We know from prior comments from Hypex this is a hard problem to solve in Class D. This amp hasn't solved it. We also know it can cause IMD which is much more obnoxious to the ear than low order harmonics since there is no masking by the music. We see the bad 19+20 sidebands confirming IMD. There's a sea of trash in the multitone, unlike say, a NCx500. Noise is good, but we know noise isn't a major audibility issue in any event, in terms of being objectionable. We also know 1kHz results don't say all that much about audible problems. So what we see is an amp that is maybe mass market receiver level, but scores high on the SINAD chart.

Is it an awful product? No. It's just really not very good, either.

 

[kyuu]

We also know it can cause IMD which is much more obnoxious to the ear than low order harmonics since there is no masking by the music. We see the bad 19+20 sidebands confirming IMD.

Weird since Amir said right under that graph: "Fortunately there is zero content out there with full amplitude 19 and 20 kHz tones so practical impact is nill."

The test results. It's actually .2% at 15kHz.

Yeah I see it now. The question is, how much does that rising distortion at treble frequencies matter? Is it at all audible? Aren't the second harmonics of 10kHz and 15kHz up at 20kHz and 30kHz, respectively?

So what we see is an amp that is maybe mass market receiver level

Definitely not. I'd be thrilled with an AVR with this level of performance. Maybe with a little more juice.

 

[Brian Hall]

USB out to an external DAC

Why would you want that with a streamer/dac/amp already? The external dac won't be any better.

 

[elmoe420]

I have to assume you have never experienced the full glory of being able to build playlists that mix your own files with tracks from different services. And being able to browse them and modify them on the fly.

Everyone has different priorities.

No, I have never created playlists for SiriusXM stations or Audible audiobooks. Maybe I'm missing something but I don't see why or even how you would do this.

 

[GXAlan]

The question is, how much does that rising distortion at treble frequencies matter? Is it at all audible? Aren't the second harmonics of 10kHz and 15kHz up at 20kHz and 30kHz, respectively?

Personally, I really enjoyed my 300B SET when it was in my care and that just had a 22 dB 5W SINAD. But there is a dichotomy where companies like PS Audio are criticized for poor measurements when it’s probably not audible, and sometimes the cheap amps with issues like this get a pass because it’s not audible.

That said, this post (and thread) may be helpful.

Post in thread 'THD above 10khz - why does it matter?'
https://audiosciencereview.com/foru...ve-10khz-why-does-it-matter.15356/post-545553