WiiM Amp Pro Streaming Stereo Amplifier Review

[whale1]

Folks,
a new Wiim Amp Pro user here, it arrived yesterday.

Did anybody experience an interference of Wiim Amp (Pro), when turned on, with a DAB (Digital Audio Broadcast) receiver signal? (Germany, Switzerland).
I planned to use the Wiim Amp Pro together with an external DAB+ unit to listen to local radio stations but the second I turn the Wiim Amp Pro on, there is a strong interference in the DAB band.

• Without the Wiim Amp Pro turned on, the signal is 100%, no errors.
• With the Wiim Amp Pro on, the signal quality goes way done. Receive errors, many of them. The signal quality is 20%.

It is not unlistenable. The receiver still delivers listenable DAB stream, but there is obviously a strong interference in the DAB band. Once I put the Wiim Amp Pro to standby mode, the interference goes away and the DAB tuner see 100% signal with no errors.

Anybody (in the DAB-enable countries) has seen this?
I haven't seen this problem with any other of my equipment (albeit significantly older; Yamaha, Technics).
The combination of the DAB tuner and Wiim Amp (Pro) seem to be a no go.


Other than that, the Wiim Amp Pro is great. Streaming, Network Radio. In internal power supply totally silent).

(Yes, I know, I can listen to my radio stations over internet and forget the DAB reception. Wireless radio is for non-stationary use anyway [in a car] and FM is dead in Switzerland anyway. )

 

[rsbroer]

Folks,
a new Wiim Amp Pro user here, it arrived yesterday.

Did anybody experience an interference of Wiim Amp (Pro), when turned on, with a DAB (Digital Audio Broadcast) receiver signal? (Germany, Switzerland).
I planned to use the Wiim Amp Pro together with an external DAB+ unit to listen to local radio stations but the second I turn the Wiim Amp Pro on, there is a strong interference in the DAB band.

• Without the Wiim Amp Pro turned on, the signal is 100%, no errors.
• With the Wiim Amp Pro on, the signal quality goes way done. Receive errors, many of them. The signal quality is 20%.

It is not unlistenable. The receiver still delivers listenable DAB stream, but there is obviously a strong interference in the DAB band. Once I put the Wiim Amp Pro to standby mode, the interference goes away and the DAB tuner see 100% signal with no errors.

Anybody (in the DAB-enable countries) has seen this?
I haven't seen this problem with any other of my equipment (albeit significantly older; Yamaha, Technics).
The combination of the DAB tuner and Wiim Amp (Pro) seem to be a no go.


Other than that, the Wiim Amp Pro is great. Streaming, Network Radio. In internal power supply totally silent).

(Yes, I know, I can listen to my radio stations over internet and forget the DAB reception. Wireless radio is for non-stationary use anyway [in a car] and FM is dead in Switzerland anyway. )

Your older equipment without the DAB quality issue is probably still lineair power supply based, using transformers.
All these modern compact amps nowadays are using switching power supplies and also have mostly class D amp stages.
So a lot of switching going on causing EMC issues, especially when other equipment is located nearby.
Try moving your DAB radio away if possible, using shielded interlinks, maybe even a line filter to lessen the pollution generated by the WiiAmp

 

[Wolf11Man]

Connect your DAB+ tuner with an external antenna, just like you would do with an FM tuner. Keep the antenna about 5-10 meters away from any class D amp or switch mode power supply. The loudspeaker cables from a d-amp can act as bad antennas as well.

DAB+ uses the FM band just like analog radio, you just don't have any reduced quality from a weak signal. It is simply 100% or zero. Sometimes you are just in between and get anoying On/Off reception.
Some of the promised advantages of the digital radio are just promotion lies. It doesn't work without any problems as promised, but has it's own.
Analog FM is simply a very old and well developed kind of technique and has worked quite well for many decades. I have an old 1986 Onkyo FM tuner, one of the finest ever build, which produces a remarkable good sound leaving not much to be desired. It was quite expensive at its time and is full of electronics.
On the other hand, when DAB+ has a strong signal and the station feeds high quality content, it makes FM look very old. All that from a very limited amount of parts, for only a fraction of an FM tuners price.
Best is to have a DAB+ tuner with a digital out and leave the D/A conversion to a capable DAC. In an AVR for example. Same as you may do with an external streamer.

 

[alessandrovle]

Did anyone already tested Pro-Ject Stereo Box E and compared to the Wiim Amp Pro? Are they on a similar level?

 

[REK2575]

Odd, the Amp Pro disappeared from the Crutchfield site (... particularly odd because I bought one from them a few weeks ago!). Not listed as 'out of stock,' just gone. Wiim Amp is still available.

Amazon looks like one of the few places still offering the Amp Pro.

 

[marcoke]

I found that rondoson has AMP PRO on Google, and the price is slightly lower than Amazon. Has anyone bought it before?

 

[DRC]

Anybody (in the DAB-enable countries) has seen this?

I have seen (heard) audible distortion on a DAB radio caused by cheap LED light bulbs. My Denon CEOL N11 has a class D amplifier and a DAB tuner so the problem is not class D amplifiers per se.

 

[REK2575]

I found that rondoson has AMP PRO on Google, and the price is slightly lower than Amazon. Has anyone bought it before?

I haven't bought from rondonson before -- maybe others here have. But I'd be very skeptical of a seller already offering a discount on WiiM's newest product that is barely available anywhere else!

 

[Pritaudio]

I would like to know if I can use the usb port on the wiim amp pro to output digital signal to external dac etc...
It could serve as having the features of the Wiim ultra but with an inbuilt amp ( if you decide you need the amp section later).
So, does the usb port on the Wiim amp pro support digital out for this to be suitable option.
It seems like a good use scenario because the amp pro doesnt have coaxial or tosling digital output, and I will be using an external dac anyway.

Im not sure if it would limit the lifespan of the amp section always being on and not being attached to speakers in the long term.

it also requires that the sub out and usb digital out are varying the same amount volume wise.
is that what would happen, as the usb digital out volume can be varied in the digital domain.

 

[staticV3]

I would like to know if I can use the usb port on the wiim amp pro to output digital signal to external dac etc...

You can.

 

[Pritaudio]

that answers some of it.

Who knows how long the usb port can be used in this manner, with future updates though.

 

[EddNog]

that answers some of it.

Who knows how long the usb port can be used in this manner, with future updates though.

The USB output should always be able to output digital audio this way to an external DAC. That being said, until they actually release it, there is currently no way for the Amp Pro to apply bass management with a USB external DAC by sending subwoofer signal out from the subwoofer output while high-pass filtering the USB output, the WiiM Ultra does this because it will high-pass filter the digital output from the coax and optical outputs while low-pass filtering the analog LFE signal from the subwoofer output.

WiiM says they are officially working on allowing this capability, however. In the future, one may yet be able to output a high-pass filtered signal via USB to an external DAC while outputting to a subwoofer via LFE output. Just have to wait for this feature to actually come out.

-Ed

 

[pedros_2005]

Forget dab radio or even fm radio (except car). Who listen on old analog radio in internet era, with thousands radios online? Wiim have tunein integrated, also radio paradise, top notch quality...

 

[Gurra1980]

Will this amp work with my martin logan esl electromotions? I have a smsl da-9 now that they sounds good with, but I have a problem with the amp so I want to change to a new one. I know these electrostats dod down very low in impedance, so that is sometimes a problem.

 

[staticV3]

Will this amp work with my martin logan esl electromotions?
I know these electrostats dod down very low in impedance, so that is sometimes a problem.

The WiiM Amp Pro has a minimum load impedance of 2.67Ω.

The ElectroMotion ESL has a minimum impedance of 4.79Ω, according to S+V (Link).

4.79>2.67, so no issues there.

 

[ghoti]

This is a review and detailed measurements of the WiiM Amp Pro networked streaming stereo class D amplifier. It was sent to me by the company and costs US $379.
View attachment 394860
The package is minimalistic in nature and matches the "non-pro" version of the amplifier. The volume indicator is that set of LEDs. They are modulated though to show partial levels with dimming which is nice. The included app is quite sophisticated with many features which is one of the key differentiators for the company products. This revision adds PFFB (post filter feedback) which should do away with the load dependency of the non-Pro version.

Back panel shows nice inclusion of HDMI ARC (I still can't test this) and sub/mains output which actually works since you can apply filters to both.
View attachment 394866
Digital inputs are in the form of streaming and Toslink. Nice to see inclusion of power supply which is rare in this price/power class.

If you are not familiar with the measurements that are about to follow, please watch my tutorial on testing power amplifiers:

WiiM Amp Pro Measurements
Let's start with toslink input and our usual 5 watt output of 1 kHz tone:
View attachment 394868
That is excellent performance, landing the WiiM pro in that very class in our rankings:
View attachment 394870
I am showing the non-pro version in dashed highlight, indicating good level of progress made:

View attachment 394871

Analog input is digitized so doesn't have the same performance but should be good enough for a turntable and such:
View attachment 394872

Noise performance is excellent:
View attachment 394873

Even at 5 watts you easily clear the hurdle for 16 bit audio which many at much higher cost amplifiers fail at.

Let's get to the main test, which is frequency response:
View attachment 394874
We see peaking but it is outside of the audible band and at any rate, shows essentially no difference with the two load impedances. PFFB works!

Multitone performance is very good up to lower treble but then it rises some:
View attachment 394875

That results in less than stellar 19+20 kHz intermodulation distortion:
View attachment 394876
Fortunately there is zero content out there with full amplitude 19 and 20 kHz tones so practical impact is nill.

Crosstalk/channel separation is excellent:
View attachment 394877

Digital crossover works as expected:
View attachment 394878

Let's see how much power we have into 4 ohm load:
View attachment 394879
Output is limited to avoid clipping. 117 watts is plenty though for where this amp will get deployed. 8 ohm works the same way:
View attachment 394880
Keep in mind that most speakers have 4 ohm impedance in low frequencies where there is most demand for power.

Changing frequencies highlights the rising distortion with frequency yet again:
View attachment 394881
Ability to produce the same power at 20 Hz is impressive for such a compact design.

Reactive loads are handled well as long as you stay at 4 ohm and higher:
View attachment 394882
View attachment 394883

Amplifier is stable at power up:
View attachment 394884

Sorry, forgot to capture thermal image. The package insulates the insides anyway so wouldn't be very accurate.

Conclusions
Just about every measurement has subjective assessment of "excellent" showing the company has paid attention to all aspects of the design. It is in every way improved over the original version which warms my heart. Functionality is top notch with streaming and sophisticated app support. Price is quite reasonable for all this functionality, power and performance.

I am happy to recommend the WiiM Amp Pro.

P.S. Yes, I have the Ultra version as well. Hope to test that soon.

------------
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/

Thanks much! I am new to the forum and planning to spring for the Amp Pro (just waiting to see if WiiM will offer a Black Friday discount on Amazon (US). I already own a pair of Borea Triangle BR03s (thanks for the review of those, as well) that sound pretty good to my inexpert ears (driven by my Denon AVR-S760H that I am about to junk out of frustration with the repeated trips into protected mode, resets, hours spent trying various solutions and time wasted with support).

Couple of questions:
A 'dumb one" to start. I am almost certain the answer is no, but can one output through the USB port? (I would use that and a dongle to use wired headphones)
I'd be glad if someone could provide suggestions for the Amp Pro Room Correction, followed by equalizer and/ or equalizer presets for best flat response with my BR03's. I listen primarily to classical music, including CDs (I plan to connect my CD deck via toslink).
FWIW, I also have a center speaker that I have been using for its ability to reproduce dialogue and lyrics. Guess there is no way to connect that? (I plan to connect my TV with the HDMI ARC.)
Do I want to get a subwoofer? Which should I consider? (adhering to the price range demonstrated by what I already own, and considering what I listen to -- I have no desire for room-shaking exaggerated bass).

 

[kyuu]

Couple of questions:
A 'dumb one" to start. I am almost certain the answer is no, but can one output through the USB port? (I would use that and a dongle to use wired headphones)

Yes, the USB port can be used for audio out.

I'd be glad if someone could provide suggestions for the Amp Pro Room Correction, followed by equalizer and/ or equalizer presets for best flat response with my BR03's.

For EQ, start with the recommended settings here. For room correction, just follow the directions provided by Wiim.

I listen primarily to classical music, including CDs (I plan to connect my CD deck via toslink).
FWIW, I also have a center speaker that I have been using for its ability to reproduce dialogue and lyrics. Guess there is no way to connect that? (I plan to connect my TV with the HDMI ARC.)

Yeah the Wiim Amp is 2.1 only.

Do I want to get a subwoofer? Which should I consider? (adhering to the price range demonstrated by what I already own, and considering what I listen to -- I have no desire for room-shaking exaggerated bass).

Yes you want a sub. I'm not sure how limited you are in terms of pricing. $200? $500? Where are you located? Options can vary depending on the market. I might suggest a refurb Kef Kube 10b for $399 to start.

 

[ghoti]

Yes, the USB port can be used for audio out.

For EQ, start with the recommended settings here. For room correction, just follow the directions provided by Wiim.

Yeah the Wiim Amp is 2.1 only.

Yes you want a sub. I'm not sure how limited you are in terms of pricing. $200? $500? Where are you located? Options can vary depending on the market. I might suggest a refurb Kef Kube 10b for $399 to start.

 

[ghoti]

Thank you!

 

[DazST]

Got mine last Saturday and have been toying around with it a little. Impressions so far are very good. Will compare it to the Pro Plus streamer plus NAD 316bee mk2 out of curiosity but very likely keep this one. Functionality is top notch, and the sound is very good to my ears.

Power is more than enough for me with 86db bookshelf speakers, never get beyond 50/100 volume. RC works, but to me it’s more like an alternative EQ setting. Rock sounds subjectively better with Rock EQ while classical sounds better with RC on than with Classical EQ. Is there a way to correct for the room first and then EQ for the music style on top of that? When I turn RC on the EQ always switches to auto.

Major „complaints“ so far: I think the amp reveals bad recordings that went unnoticed before. Some recordings I enjoyed before I now find fault with. I tend to listen to the sound now rather than the music, but that probably will stop once the novelty wears off.

I have the same NAD amp so would be curious to see how you're finding the WiiM in comparison.

Also, is it strange that there aren't many other reviews on this yet, particularly in comparison to the original? Too soon?