WiiM Amp Streaming Amplifier Review

[StefanSweden]

Their latest roadmap update (10 Feb 24) says they’re working on 8 band PEQ and room correction for the Amp (and Pro/ Plus) as well as other stuff.

WiiM Amp Roadmap

Updated on Feb. 10th., 2024 What we're working on … We want to give you visibility into some of the features we are working on. Our official release notes have the complete list of released features. If you want to make a feature or pr...

faq.wiimhome.com

Is the PEQ feature a software thing? Im thinking of Bluesound Powernode which not have a PEQ - could that be fixed via a software update?

 

[staticV3]

I have been very late with this review myself.

Your measurements show the problems I saw in the first sample with rising distortion in low frequencies.

Earlier hardware revisions of the WiiM Amp had problematic distortion at low frequencies:

My WiiM Amp tests, chapter 2

A new unit is with me. Because new device is too cold to be powered, I can focus on external differences. Both units are almost undistinguishable. One difference is reversed channels on RCA inputs. Second one is a class II power supply mark printed on the bottom. I've seen units with reversed...

forum.wiimhome.com

It would be useful if you could state in your review which PCB version your WiiM Amp has.

To check, the Amp needs to be in your local network, then you just open https://xxx.xxx.xxx.xxx/httpapi.asp?command=getStatusEx in a browser on your PC/laptop/phone, replacing xxx.xxx.xxx.xxx with the IP of your Amp.

PCB_version returns the hardware revision.

 

[Brantome]

Is the PEQ feature a software thing? Im thinking of Bluesound Powernode which not have a PEQ - could that be fixed via a software update?

It’s done in the device firmware so they could do it if the processor/RAM the PowerNode has is up to the task.

 

[Waxx]

It's a decent all in one system stereo system for a small price, that works with most cheaper passive speakers that are out there. That is something that is needed. If the software is also very easy for noobs this could be a popular device very soon. You just need to add speakers (old or new) and a streaming account or another music source to have a finished system.

 

[VintageFlanker]

Your measurements show the problems I saw in the first sample with rising distortion in low frequencies.

Exactly. The 200Hz in particular was acting crazy (it goes way up to 10% THD+N). But my sample is an early build that was sent back in November. I know that they fixed the PCB since.

I've seen on WiiM Forum that early buyers could ask them for an updated PCB.

 

[NHL99]

Very limited amp according to

 

[Jeromeof]

Very limited amp according to

Well that is according to very limited reviewer !!

 

[Yevhen]

And

output filter feedback to eliminate low dependency of the frequency response

and significantly improve THD!

 

[Haskil]

This is a review and detailed measurements of the WiiM Amp streaming amplifier. It was sent to me by the company and costs US $299.
View attachment 350879
I was pleasantly surprised by the good bit of weight this small box has. It will help it not slide with the weight of the speaker wires and such. Back panel shows the differentiation from a regular amplifier:
View attachment 350880
With included streaming, you have a one box solution to play your content over the network. You can use the included Bluetooth remote or the application. The latter was rock solid which is more than I can say about some other (major) streaming amplifiers. It instantly found the device, upgraded its firmware and allowed reliable control of all function. I can't do justice to all of its capabilities in this performance related review but suffice it to say, it is very capable.

HDMI ARC allows a smart TV to feed the amplifier signal for content you play internally to your TV. A nice quality HDMI cable was provided (in addition to Toslink and even RCA) which was appreciated.

The only complaint I have is with similar looking subwoofer out. Looking from above, I thought that was the other input channel and spent good bit of time trying to figure out why I was only getting sound out of one channel. Having it be located elsewhere would help as opposed to being lined up with the left audio input channel.

Another nit is the rotary volume control not always acting on the volume. You would have to go two notches for example to change volume.

This review has taken a while to get out. The first sample I received performed well in most of the tests but showed quite an increase in distortion at lower frequencies. This manifested in Multitone test and power vs frequency sweeps. I ran the results by the company and they said this was an early production problem that was fixed. They sent me a new one which almost remedied that problem.

WiiM Amp Amplifier Review
With access to AP's APx516 analyzer, I was able to test the HDMI ARC on WiiM Amp:
View attachment 350882
This puts the amplifier comfortable above our average of all amplifiers tested:
View attachment 350883
View attachment 350884
For streaming, I wanted to use Roon but seems that is not there yet. Fortunately Chromecast is there which provides similar high performance streaming:
View attachment 350885
So no difference with respect to which digital input you use. Analog streaming in the first sample I tested was a bit worse with SINAD of 85 dB. The new sample degraded some with low frequency noise down to 80 dB (not shown). I assume this is not material to most users where analog input is only used for LP and such.

Cycling through inputs, here is dynamic range using Toslink:
View attachment 350887

Frequency response unfortunately shows the typical load dependency in lower cost class D amplifiers:
View attachment 350889

Here is the sub out:
View attachment 350892

As noted, multitone shows good performance now:
View attachment 350888

19 and 20 kHz intermodulation test shows the increased distortion there:
View attachment 350890

Crosstalk wasn't that great with analog input (inset) but very nice with digital:
View attachment 350891

Normally I sweep power with analog input but since digital is much better, I used that: [edit: "8 ohm" label is wrong in the first graph, should say 4 ohm).
View attachment 350893
View attachment 350894

Unless you use analog input, the gain settings is designed such that you never clip. This means that the "peak" power is the same as what I have measured above. Spec is 120 watts at 4 ohm and we are achieving that so no issue there. Same with 60 watt specified for 8 ohm.

Here is power sweep at different frequencies:
View attachment 350895
The graphs are well behaved for a class D amplifier. 20 Hz distortion though, rises good bit (dashed yellow).

Finally, the amplifier is stable on power up:
View attachment 350896

Conclusions
The WiiM Amp is a very well executed streaming, multi-room amplifier. It easily plays against big boys of streaming despite lacking their name recognition. Objective performance is very good for the class. The only wish is post output filter feedback to eliminate low dependency of the frequency response.

I am going to put the WiiM Amp amplifier on my recommended list.

------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

In 1974, a Rotel RA 810 amp was worth 2,500 French francs, two and a half times the legal minimum wage at the time (the SMIC), it developed 40 watts at 8 ohms... and it was cheaper than a Sansui , a Pioneer, a Yamaha of the same power.
To listen to music with it, you had to buy an LP player and a cartridge for the same price and a tuner, I bought a Sony ST 5130 for 2500 francs also... So you had to spend 7500 francs... or 7 months of the legal minimum wage in France at that time... Not counting the speakers which were worth around 3000 francs per pair... or 3 months of Interprofessional Minimum Growth Salary... Without doing complex calculations, I can say that today we buy the Wim amp tested here, plus a pair of very good quality acoustic speakers for 1000 euros (1000 dollars) today... For undoubtedly superior quality... Let's go crazy for a pair of speakers for 1100 euros...
The same minimum wage in France today is 1400 euros net... the price of Wim Amp and a pair of Speaker at 1100 euros...
From 10 months of minimum wage we went to less than a month or a month...
Ah yes, there is a little treble reading with 8 ohm speakers... But not the hiss of the FM, not the distortions of the LP... and in addition we have 4 parametric corrections available plus one subwoofer output...
Thank you Amir for putting a recommendation to such a device...

PS : Oh I forgot, with certain cells there was a rise in the treble in the audible band at a very audible level which required adding small polystyrene capacitors to some of them to calm down this rise in the treble well. more important than that of economical class D amplifiers...

 

[ctrl]

So, how will the WiiM Amp FR be if it powers up a pair of JBL Studio 590 speakers?

All of which makes me wonder, if in real life this issue can be easily and effectively »un-eq’ed« at all.

The impedance measurement of the JBL 590 bears a strong resemblance to the complex load used by Erin in his WiiM Amp review (more details can be found here). Therefore, it is likely that the impedance curve of the JBL 590 in the presence range of 2-4kHz will create a frequency response bump of approximately 0.6dB with the WiiM Amp.

This should be audible, but not in the sense of "every piece of music sounds wrong", rather more like "some music pieces exhibit somewhat aggressive-sounding parts".

This impression could be further amplified, depending on the Quality factor (Q) and the exact location of the frequency response peak performed by the WiiM Amp (due to the speaker load), by the sound power, early reflections, and PIR (Power Impulse Response) curve of the JBL 590, as it already exhibits a slight bump in the presence range (see purple rectangle):

For those without a calibrated measurement microphone and knowledge of how to perform quasi-anechoic frequency response measurements, one can try to eliminate possible tonal inconsistencies purely by EQ by ear or implementing an impedance linearization for a few dollars to minimize the effects of amplifier load dependency.

Since Amir has measured the impedance frequency response of the JBL 590 it's easy to do so. After importing the JBL 590 impedance measurement into VCAD, impedance linearization can easily be performed.
In case of the JBL 590, a Zobel network consisting of a 22µF electrolytic capacitor and a 12-ohm ceramic resistor for around $4 should suffice (green impedance curve is with Zobel network):

With the Zobel network connected in parallel to the speaker terminal of the JBL 590 (more details here), the frequency response of the WiiM Amp should then approximately match what Amir measured with the constant impedance load of 4 and 8 ohms (somewhere between).

 

[Matias]

The low power and high distortion with low frequencies of the WiiM Amp, along with the nice sub out + high-pass speakers, makes it ideal indeed for a 2.1 system. I would not expect it to drive hard to drive tower speakers or so. Just a pair of good bookshelf speakers and a decent sub. Something like a pair of Ascend Sierra 1 V2 + SVS SB2000 Pro for a killer system.

 

[Yorkshire Mouth]

The rhino in the bathroom - excellent as this is, wouldn’t a matching pre amp (same thing but without the amp stage) have been great.

Buy the pre amp, then chose your own amp for your own needs, whether that’s an £80 Fosi Audio V3 or an £800 Topping LA90.

Hopefully the upcoming WiiM Ultra will be all that and more.

 

[_thelaughingman]

Not really impressed with the performance on this!

 

[Zapper]

This is a much neater streaming solution than my WiiM Mini + USB wall wart + Aiyima A07 + power brick. It's worth the price just to clean up that mess of wires.

 

[Ajax]

I'm the first to complain about the load dependency of small class D designs, but here you guys really don't know how you think that a amplifier plus streamer, plus hdmi in a nice case, with a serious amount of power, that also provides low pass filters and high pass and even integrated peq for 300 euros should not be recommended..... It's an incredible value, and if with your speakers the load dependence should give you excessive brightness you just need to use the peq filters.
This product is exceptional.

Couldn't agree more. This ticks a lot of boxes for music lovers on a low budget.

Big plus here is the App, stability of the streamer, and the high pass on the mains and low pass on the sub out, which we asked Fosi to implement in the previous thread.

Perfect for a second system or for those starting out in hifi - just add a pair of Elac or Wharfdale bookshelves and a second hand sub .... $700-$800 total for great sound and convenience.

The Audio World is a wonderful place at the moment with more and more inexpensive high performance gear being produced.

 

[Yorkshire Mouth]

Perfect for a second system or for those starting out in hifi - just add a pair of Elac or Wharfdale bookshelves and a second hand sub .... $700-$800 total for great sound and convenience.

The Audio World is a wonderful place at the moment with more and more inexpensive high performance gear being produced.

THIS!

Indeed, reading Amir’s review of this and the Wharfedale Diamond 12.1s, that would be a main system set up where you’re a long way down the road of diminishing returns.

 

[VintageFlanker]

The low power and high distortion with low frequencies of the WiiM Amp, along with the nice sub out + high-pass speakers, makes it ideal indeed for a 2.1 system.

HPF measurements added :

 

[Sokel]

HPF measurements added :
View attachment 351003

Did it happen to measure any THD+N (specially N) with the filters on?
That would be super useful,specially down low.

 

[CleanSound]

Well that is according to very limited reviewer !!

At least he doesn't believes in cables.

 

[Brantome]

At least he doesn't believes in cables.

Cables really do exist. I even use some