WiiM Amp Pro Streaming Stereo Amplifier Review

[morillon]

I think that one of the main things to watch out for here...and the stories from the last fosi remind us that it's really for a story of reliability viability etc...the heat management aspect in standby or in charge..what about it there...?

 

[Yifu]

!!My WiiM family has added another powerful member ;D

 

[morillon]

I'd just like to see hf distortion come down a bit to match the rest of it. Just a probably daft hunch, but I'm minded of metal dome tweeters taking off at 30 - 40kHz, often badly. Add the distortion harmonics and just possibly/maybe (maybe not), any intermodulation effects might come down into the audio band - maybe/possibly (maybe not).. The rest of it seems great and the price is very low really for a little box like this (my local audio salon now sells them as well - wonders never cease!!!), so forgive my excessive caution here.

perhaps play with type of filter at 44-48k of the dac chip can help a little.. ;-)

 

[DSJR]

Translate into percentages, the distortion of - 54 dB at 15 Khz, - 62 dB at 10 Khz and - 68 dB at 5 Khz... and you will undoubtedly be less disappointed.

Even if obviously, we would have preferred even better distortion figures that do not change with the amplified frequencies, as well as lower intermodulation distortion, even if here again the values are all below - 68 dB...

Many of yesterday's renowned integrated amplifiers and amplifier blocks, both transistor and tube, do no better. But are much more expensive.

If we look at what this Wiim Amp Pro gives for the market today, at the price it is sold for and if we take a time machine to see what we could buy as an integrated amplifier for the same amount of money in 1982, the year the CD was launched... You won't find much for a hundred dollars-euros...

I have just celebrated my 70th birthday and I am resolutely in the camp of "it was much less good and much more expensive before"...

Back in 1982 or so, amp distortions of -70dB midband and -60dB IMD (19 + 20khz) seemed commonplace. Far eastern designs with all distortions down up to the -90 level, weren't regarded as 'good' subjectively and this is where the dichotomy of measurements vs. perceived sonic quality started, tech reviewers of the time perpetrating and majoring on this aspect

Taking two well known 1980s brands (tribal followings even then) Quad 405-2 and Naim 250 (all the latter maker's amps used basically similar amp circuits) didn't have better figures (latest production is, however, orders of magnitude better in fairness)

 

[Petevid]

Possibly a silly question but can a turntable be connected to the phono input without the need for a phono pre-amp? The Wiim blurb claims a turntable can be connected, might there be a toggle option for turntable in the software for the phono input, line/turntable perhaps? Or does the A to D conversion take care of it?

 

[Sokel]

I'd just like to see hf distortion come down a bit to match the rest of it. Just a probably daft hunch, but I'm minded of metal dome tweeters taking off at 30 - 40kHz, often badly. Add the distortion harmonics and just possibly/maybe (maybe not), any intermodulation effects might come down into the audio band - maybe/possibly (maybe not).. The rest of it seems great and the price is very low really for a little box like this (my local audio salon now sells them as well - wonders never cease!!!), so forgive my excessive caution here.

I'm with you at it.
I prefer a 16-bit performance all over than some impressive individual chart.
And that includes multitone,IMD and level vs freq for the last 25dB.


But it has nice looks and will be a nice set with the proper speakers (visually at least)

 

[Dennis_FL]

@amirm thanks for the review and glad to see it receives your recommendations

Hope and wish to see your review of ULTRA at the earliest , which would help in deciding, whether to add it to my setup or not

I bought the Ultra and have no regrets. I was playing some albums I know well with the Ultra and it did fine. Later I fed the USB out into my Gustard DAC and the Gustard was definitely a step up and quite noticeable on albums like Tubular Bells. I bought a Fosi amp to pair with it.

 

[JeremyFife]

Nice little amp that could replace my Naim UnitiQute for tv duties. However, the lack of a pre- out is fair at this price point but maybe something some might want.

It does have USB out, so you could use that

 

[morillon]

just a shame that there is no correct headphone output and a pre-out for possible evolution... but hey the lots of the old ones are sold off..should drop in price and become, if we are well aware of its limits etc. a nice deal for a small system, more clearly often emerges a use more "on the TV" more than hi-fi ..and the subject to check. it's the latency....(??)

Nice little amp that could replace my Naim UnitiQute for tv duties. However, the lack of a pre- out is fair at this price point but maybe something some might want.

 

[Haskil]

I'd just like to see hf distortion come down a bit to match the rest of it. Just a probably daft hunch, but I'm minded of metal dome tweeters taking off at 30 - 40kHz, often badly. Add the distortion harmonics and just possibly/maybe (maybe not), any intermodulation effects might come down into the audio band - maybe/possibly (maybe not).. The rest of it seems great and the price is very low really for a little box like this (my local audio salon now sells them as well - wonders never cease!!!), so forgive my excessive caution here.

So what's in a musical recording at such high frequencies?

What commonly used acoustic music miking mics - I'm not talking about the ones used for some unrealistically well-made test recordings to show that there are harmonics at a high level after placing the mic in the mouthpiece of the trumpet or flush with the piano strings at the very end of the soundboard -, go above 20-21 Khz? Not the great Neumans anyway. Some B&K go higher but they don't have much to capture when they are 2 m or more from the instruments to be recorded... And what is there to record at these frequencies in a concert hall ?

Not much and on an infinitesimally small level...

What effects potentiated with each other could have effects an octave or two lower that would measure up and be found in the audible band?

I don't know... if someone can tell us...

 

[Dennis_FL]

Interesting is the digital out and sub out can work simultaneously with bass management since the sub has a separate DAC.

 

[Burnside]

Interesting is the digital out and sub out can work simultaneously with bass management since the sub has a separate DAC.

What digital out? Are you referring to the Ultra rather than the Amp Pro?

 

[Inertiaman]

Possibly a silly question but can a turntable be connected to the phono input without the need for a phono pre-amp? The Wiim blurb claims a turntable can be connected, might there be a toggle option for turntable in the software for the phono input, line/turntable perhaps? Or does the A to D conversion take care of it?

It does not have a phono RIAA preamp circuit. The turntable reference in the Wiim marketing assumes a contemporary model with integrated RIAA.

The Ultra streamer does have a proper phono input w/ ground.

 

[Inertiaman]

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

FWIW, in a recent Wiim forum discussion, the Wiim folks stated that the minimum impedance load for Amp and Amp Pro is 2.67 ohms.

 

[Inertiaman]

just a shame that there is no correct headphone output and a pre-out for possible evolution...

Amir has reviewed several very inexpensive, high-performance headphone amp / DACs which could easily be connected to the USB to provide this functionality. While not as convenient as a front-panel jack, it shouldn't be viewed as a show-stopper.

 

[Brian Hall]

Needs USB c and coax inputs. Another RCA in would be nice to have too. Also a headphone amp. Close but not quit there for a nice all in one.

 

[morillon]

So what's in a musical recording at such high frequencies?

What commonly used acoustic music miking mics - I'm not talking about the ones used for some unrealistically well-made test recordings to show that there are harmonics at a high level after placing the mic in the mouthpiece of the trumpet or flush with the piano strings at the very end of the soundboard -, go above 20-21 Khz? Not the great Neumans anyway. Some B&K go higher but they don't have much to capture when they are 2 m or more from the instruments to be recorded... And what is there to record at these frequencies in a concert hall ?

Not much and on an infinitesimally small level...

What effects potentiated with each other could have effects an octave or two lower that would measure up and be found in the audible band?

I don't know... if someone can tell us...

which is interesting and which fundamentally, we cannot consider as "hifi" this behavior they say "erratic" in f-r of these little chips, case by case, despite the effort of the pffb really helps to erase this problem...the loads are complex, see, and it surprises me that not enough is said, often very higher than 8ohm on the tweeters (what does 2k-20k measurements give under 16 see 32ohm?)...and as we can see affect quite low the fr in areas that are already sensitive, see at crossings that are already often complicated...not only very high (doesn't concern me)...
but this pffb really clearly helps for this """mk2"""...good news


Thread 'Complex impedance load amp FR influence - WiiM Amp review by Erin' https://audiosciencereview.com/foru...p-fr-influence-wiim-amp-review-by-erin.52301/
(It should come as no surprise that many of these little amplifiers based on these chips, until the recent arrival of the pffb, ended up (at least around me) after a passage of "for the price it's still astonishing!'.. .at the bottom of the cupboards, see just for troubleshooting, " too stiff or tiring", among those who had hindsight on the use of small class ab amps etc in the same circumstances... the pffb will clearly level out this problem a little ;-))

 

[Dennis_FL]

What digital out? Are you referring to the Ultra rather than the Amp Pro?

USB out to an external DAC

 

[Inertiaman]

In anticipation of the inevitable "when is it available?" inquiries . . . the Amp Pro had been available for pre-order over the past several days at Amazon US (though curiously it disappeared last night) and still is at Crutchfield. Wiim mentioned in their forums that units should hit the Amazon distribution line by early next week.

So the short answer is "imminent".

 

[JeremyFife]

What digital out? Are you referring to the Ultra rather than the Amp Pro?

https://wiimhome.com/wiimamp/specs USB Audio out