WiiM Amp Streaming Amplifier Review

[Sokel]

I can't say I know what is typical for the speakers that really give these types of amps problems. But with the C-note impedance curve (simulated below), there is minimal wiggle except for the strong resonant peak, so pretty similar shape to the case of a pure resistor load. If you know of speakers that would cause a more chaotic curve I would sincerely like to know about them just out of curiosity.
View attachment 352006

I picked the first four from speaker threads:



The first three would have a single peak,narrow or broad (third one broader up to the top probably) at different frequency areas,the fourth one will have a double one covering quite a range.

 

[pjug]

These for instance from Erins review:

If I am reading that right the wiggles are less than 1 dB. So his loads are not as problematic as with something like C-note. I was wanting to correct more severe problems with a single PEQ filter such that they much reduced, but not expecting to make it perfectly flat.

 

[voodooless]

So his loads are not as problematic as with something like C-note

Are you sure your sim is correct? A 13 dB peak seems unlikely. Also it should not have just one peak.

 

[pjug]

I picked the first four from speaker threads:

View attachment 352025 View attachment 352026View attachment 352027 View attachment 352028

The first three would have a single peak,narrow or broad (third one broader up to the top probably) at different frequency areas,the fourth one will have a double one covering quite a range.

Here is what I get simulating the last one (Focal Chora 816). So I take the point that it is not a simple curve but it is not a severe case like what I have been thinking about. Let me try another one.

 

[pjug]

The first one, the JBL HDI-1600 has the severe peaking much like the C-note. This is an example of what I would think one PEQ filter could do a good job of fixing.

edit: here is above with PEQ applied, and the simulation circuit.

 

[Descartes]

You can see for yourself:

Review and Measurements of Yamaha WXA-50 Streaming Amp

This is a review and detailed measurements of the Yamaha WXA-50, multi-function DAC, pre-amp, power amp, streaming and multi-room unit. It is on kind loan from a member. Even though it came out a few years ago (2016?), it is widely available. Amazon shows it costs US $478. Success of SONOS...

www.audiosciencereview.com

Looks like the amp is descent but the DAC is horrible!

 

[Head_Unit]

So, pairing the WiiM Amp with 4-ohm speakers would make this issue practically non-existent?

Technically @Mnyb is correct, the peaking might be even more than shown. Then again, at such high frequencies where most people can't even hear and there is little musical content, to me this is a tiny issue. As an audio engineer would I prefer the feedback loop out past the filter (which a coworker I hired in once implemented in automotive, first as far as I know, whee!)? Sure! But for the price and specs of this thing, eh, I'm not gonna die on that cross. Plus this thing is small enough to stick behind my wall-mount TV and power some monitors on the side...

 

[Ivanovich]

Personally, I don’t hear above 10K, but the speakers are 2-way, 4-ohms, so my young-ear’d niece should be fine too.

The HP/LP let’s the sub handle the low frequencies and relieves the amp of being pushed harder to drive the lows, which helps with my worry that it would distort when pushed.

When looking at the objective measurements and the application together, I would agree it’s recommended. Sometimes the flaws are just not applicable.‍

 

[WiiM Support]

Hi Team,

First and foremost, I want to express my sincere gratitude for all the insightful feedback you've shared. It's been incredibly valuable to us. I'd like to take a moment to share some insights into our journey with the Post-Filter Feedback (PFFB) implementation.

We've seen remarkable enhancements in SNR (Signal-to-Noise Ratio) and THD+N (Total Harmonic Distortion + Noise) performance after integrating PFFB. However, we encountered a challenge: resetting the Amp chip results in an audible pop noise. Despite our collaborative efforts with TI, we've found that this issue cannot be fully resolved at this time.

Given this, we've made the difficult decision not to include PFFB in the current WiiM Amp model to ensure the best user experience. Nevertheless, we're actively exploring solutions and are committed to potentially integrating PFFB into future products.

Thank you for your continued support and understanding. Stay tuned for more updates!

 

[Deleted member 48726]

Looks like the amp is descent but the DAC is horrible!

How come? You think this is horrible?
It looks completely transparent to me. You probably wouldn't be able to tell this apart from the Wiim or anything else with higher THD+N

Here is a test for you-->

Can you hear a difference between dac+amp path with 92dB vs. 78dB SINAD? (test)

Can you hear a difference between dac+amp path with 92dB vs. 78dB SINAD? Quite a lot has been said here about “audibility” of SINAD, or existing/non-existing sound differences between amplifiers or DACs. Quite often we forget to evaluate SINAD of the whole audio chain consisting of a DAC, power...

www.audiosciencereview.com

 

[daniboun]

Hi Team,

First and foremost, I want to express my sincere gratitude for all the insightful feedback you've shared. It's been incredibly valuable to us. I'd like to take a moment to share some insights into our journey with the Post-Filter Feedback (PFFB) implementation.

We've seen remarkable enhancements in SNR (Signal-to-Noise Ratio) and THD+N (Total Harmonic Distortion + Noise) performance after integrating PFFB. However, we encountered a challenge: resetting the Amp chip results in an audible pop noise. Despite our collaborative efforts with TI, we've found that this issue cannot be fully resolved at this time.

Given this, we've made the difficult decision not to include PFFB in the current WiiM Amp model to ensure the best user experience. Nevertheless, we're actively exploring solutions and are committed to potentially integrating PFFB into future products.

Thank you for your continued support and understanding. Stay tuned for more updates!

Well I have the feeling that your R&D is not so good) Whether it is 3E Audio, Sylph Audio, Aiyima, Fosi, XRK.... no one has encountered this problem relating to pop noise when enabling PFFB.... Wiim should therefore worry or rethink their module from the beginning
You can use reverse engineering to find the solution unless you claim that you cannot implement the PFFB on your current modules because this would have a considerable impact on the cost.....

 

[morillon]

certainly a response from "marketing"....
(which I had already observed with the first v1 of the wiim plus ;-) )

but in their defense their "amp" must have been developed during last year, and the subject pffb was not yet so much put forward it seems to me...
moreover a cost and need for space...
and wiim is on the very general public market at a reasonable cost..

 

[Sokel]

Personally, I don’t hear above 10K, but the speakers are 2-way, 4-ohms, so my young-ear’d niece should be fine too.

The HP/LP let’s the sub handle the low frequencies and relieves the amp of being pushed harder to drive the lows, which helps with my worry that it would distort when pushed.

When looking at the objective measurements and the application together, I would agree it’s recommended. Sometimes the flaws are just not applicable.‍

What 10Khz?
It's about the 2-5Khz area,where we are the most sensitive with some loads.
Read the various charts people posted here.

 

[harkpabst]

Well I have the feeling that your R&D is not so good) Whether it is 3E Audio, Sylph Audio, Aiyima, Fosi, XRK.... no one has encountered this problem relating to pop noise when enabling PFFB....

Did you read @amirm's review of the 3E Audio modules?

 

[daniboun]

Did you read @amirm's review of the 3E Audio modules?

Did you read all my projects ? Check my signature you will understand ) I opened the first 3E Audio PFFB thread before the ASR review)

If you refer to this "quiet power ON but Noisy OFF" it is not audible at all (for most of us). All SOTA TP325X boards have an anti pop circuit....

 

[harkpabst]

Did you read all my projects ? Check my signature you will understand ) I opened the first 3E Audio PFFB thread before the ASR review)

Should I take that as a "no"?

To answer your question: No. I have signatures disabled in mobile view (that's probably the forum default anyway). I also don't regularly check who was first to open a thread on any product I might or might not be interested in.

For those not reading signatures, could you bring up a short summary of which products you brought to international markets?

I'd just like to get a feeling for what makes you judge WiiMs R&S department the way you do.

Have you tested how PFFB with TPA3255 affects reactive load dependency?

 

[daniboun]

Should I take that as a "no"?

To answer your question: No. I have signatures disabled in mobile view (that's probably the forum default anyway). I also don't regularly check who was first to open a thread on any product I might or might not be interested in.

For those not reading signatures, could you bring up a short summary of which products you brought to international markets?

I'd just like to get a feeling for what makes you judge WiiMs R&S department the way you do.

Have you tested how PFFB with TPA3255 affects reactive load dependency?

I have read all the reviews relating to the TPA325X. I am at the origin of a plethora of projects based on these chips... No less than twenty to my credit.

I'm not judging but I found Wiim's response a little too "marketed " for my taste.

If you push your curiosity a little you will find my many contributions via my nickname.(daniboun)

What is the problem with reactive loads ?

"Amplifier Reactive Load Test :
This is one robust amplifier, essentially not caring about the load down to impressive 2 ohms!"

Thread '3e Audio TPA3255 Amplifier Kit 480-1-29A Review' https://audiosciencereview.com/foru...tpa3255-amplifier-kit-480-1-29a-review.50283/

 

[Ivanovich]

What 10Khz?
It's about the 2-5Khz area,where we are the most sensitive with some loads.
Read the various charts people posted here.

I did, the load dependent frequency response start to rise at about 7-8 KHz, 2-5K doesn’t seem much affected on the graph.

If it bothers you that much, pretend I didn’t mention my hearing.

 

[Sokel]

I did, the load dependent frequency response start to rise at about 7-8 KHz, 2-5K doesn’t seem much affected on the graph.

If it bothers you that much, pretend I didn’t mention my hearing.

Not at all loads,it's random and that's the weakness:

(been posted in previous pages)

 

[Ivanovich]

I am reading that graph as having les than 1dB SPL deviations, am I wrong? If not, I’d consider that an effect not worth worrying about.

It’s a $300 piece of kit and does everything I need it to do. Worrying about 1dB variation when it’s going in a room having 10-30db peaks and nulls is not for me. I could tilt or turn my head a couple of degrees and induce as much or more variation than that! But that is me.

I’m curious if any golden ear’d critical listeners have found the FR to be objectionable or even noticeable as a result of this load sensitivity issue.