WiiM Amp Ultra Users Experience

Another point that plays a role is the damping factor.
WiiM Amp Ultra has a high damping factor (i.e. low output inpedance) and is therefore for all practical intents and purposes load-independent.
This is visible in Erin's measurements as well as my own (we both measured with complex loads too).

It's of course fine if you don't like the device, but damping factor is definitely not an issue.
 
WiiM Amp Ultra has a high damping factor (i.e. low output inpedance) and is therefore for all practical intents and purposes load-independent.
This is visible in Erin's measurements as well as my own (we both measured with complex loads too).

It's of course fine if you don't like the device, but damping factor is definitely not an issue.
The value of the Damping factor is critical in any case, which is why manufacturers list it. As for the value of 94, it reminds me of amplifiers from several decades ago, and this explains its sonic behavior. I didn't write anywhere that I didn't like it, on the contrary, I wrote that it sounds good with voice and a few instruments.
 
As for the value of 94, it reminds me of amplifiers from several decades ago
You are right, competent audio amplifiers existed decades ago as well. :)

The difference in response deviation between damping factor of 94 and e.g. 300 will be in the order of about 0.1dB.
This is very unlikely to be audible or meaningful - especially when you also consider that speakers often deviate >3dB in a single axis response, and rooms often introduce deviations on the order of 10dB+. Actually, just moving your head a several cm will change the response by more than 0.1dB...

I didn't write anywhere that I didn't like it, on the contrary, I wrote that it sounds good with voice and a few ininstruments.
Sorry for my misunderstanding!
 
Yes i know it .You want to write Wiim Ultra Amp ? Ok
Sorry ,i m talking about Wiim Ultra Amp
It ,s O.k ?
There's a product called WiiM Amp Ultra and there's a different product called WiiM Ultra. Yes, it's very much appreciated if you use the actual product name instead of another product's name. (y)

As pointed out before, the product called WiiM Amp Ultra sells for <600 EUR, so it remains unclear why you mentioned a selling price of 800 EUR in one of your previous posts.

The value of the Damping factor is critical in any case, ...
In any case? Why do you think so? The damping factor is nothing but the output resistance of the amplifier relative to an 8 ohm load. There's no "magic" to it.

... which is why manufacturers list it.
Many actually don't. And if they do, it's pretty much pointless unless they specify the damping factor (or output resistance) over frequency.

As for the value of 94, it reminds me of amplifiers from several decades ago, and this explains its sonic behavior.
What do you believe is explained by this value?

Five decades ago, a fellow called Floyd E. Toole published an article about why damping factors >20 don't provide any meaningful benefit in AudioScene Canada. You might have heard of him later on.
 
Unfortunately, I notice that some commentators remind me of the corresponding commentators on the RME forum, where they consider the RME ADI 2 PRO DAC to be one of the best in the world, regardless of price. It seems that the same is happening here with some. Of course, not even the excellent engineers at Wiim believe such a thing.
 
We’re fans of the brand and its products for a reason, and that’s why we’re here. I don’t see anybody claiming it’s the best thing ever, but for many of us it IS the best choice for our needs and budget. I know that I chose WiiM after sorting through many other options, because it does exactly what I need it to at a very reasonable cost, it is very user-friendly, and there’s this extremely knowledgeable and helpful user community sharing info that I never knew I never knew. And yes, cost is a big consideration - not everyone has tens of thousands of dollars to dump on sound systems. I am completely satisfied - overjoyed, actually - with how it’s all working for me, it sounds fantastic, and there is nothing out there right now that I would replace it with. I can’t speak for everyone else, but I’m pretty sure a lot of other members here are similarly pleased. Sorry if that’s a problem for you.
 
We’re fans of the brand and its products for a reason, and that’s why we’re here. I don’t see anybody claiming it’s the best thing ever, but for many of us it IS the best choice for our needs and budget. I know that I chose WiiM after sorting through many other options, because it does exactly what I need it to at a very reasonable cost, it is very user-friendly, and there’s this extremely knowledgeable and helpful user community sharing info that I never knew I never knew. And yes, cost is a big consideration - not everyone has tens of thousands of dollars to dump on sound systems. I am completely satisfied - overjoyed, actually - with how it’s all working for me, it sounds fantastic, and there is nothing out there right now that I would replace it with. I can’t speak for everyone else, but I’m pretty sure a lot of other members here are similarly pleased. Sorry if that’s a problem for you.
It's obviously not a problem for me, since it satisfies you. I simply wrote my subjective opinion, which I think I have the right to do. By pointing out some flaws to the manufacturer-designer, I think you help him make the next product he releases better. That way, the designer will make the next one better.
 
Unfortunately, I notice that some commentators remind me of the corresponding commentators on the RME forum, where they consider the RME ADI 2 PRO DAC to be one of the best in the world, regardless of price. It seems that the same is happening here with some. Of course, not even the excellent engineers at Wiim believe such a thing.
Just to clarify my statements - I don't think the Amp Ultra is one of the best amplifiers in the world. There are absolutely amplifiers that are more powerful and/or which measure better across various metrics.

On the contrary, my opinion is that there's no such thing as "the best amplifier" - just amps that are suitable for a specific purpose, and those that aren't. In any case, audio performance is surely not the only factor that influences purchase decisions - and that is perfectly fine.
WiiM Amp Ultra is a nice package that will probably be a good fit in many cases, but definitely not in every imaginable case.

That all being said, the intention of my responses was just to point out that the WiiM Amp Ultra damping factor is not likely to be an issue, because it is high enough not to introduce significant frequency response deviation with complex loads.

There are of course amps with higher damping factors, but one has to ask when is the damping factor high enough? No amp has infinite damping factor, because real voltage sources can't have zero output impedance.

At this point it may be useful to link to this nice article by Benchmark (who seem to be proponents of very high damping factors, BTW), and this screenshot from their damping factor calculation spreadsheet:
DampingFactor-WithCables.png

As we can see, with 8Ohm nominal speaker, connected with 10ft of 11AWG wire, specific damping factor (DF) results in the following total frequency response (FR) errors:
  • DF >~25 results in FR error <1 dB
  • DF >50 results in FR error <0.5 dB
  • DF >125 results in FR error <0.25 dB
  • DF ~1000 is needed for the error to go below 0.1 dB
We can see how the relation is not linear, and how DF needs to increase disproportionately for progressively smaller improvements in frequency response error. E.g. if we look at DF=100 vs DF=1000 we see we're talking about an error difference of just 0.2dB for a DF that is one order of magnitude higher.

At this point I can suggest to readers to try and experiment with PEQ to get a sense of audibility of such low-level FR deviations - e.g. try listening with and without a -0.2dB PK PEQ filter at 150Hz with Q of let's say 0.7.

In case some find it interesting, in this old ASR post I wrote about damping factor and explained how it results in frequency response error due to simple frequency-dependent voltage division.

Another thing that is probably worth mentioning is that the frequency response error that is introduced by the amp-speaker impedance interaction (related to damping factor) can be completely corrected by EQ if one wishes to do so - though that would require first calculating or measuring the unique FR error, which is probably not trivial to do for most people. But again, considering the wider context of speaker response deviations and influence of room interaction, I don't believe this is really needed anyway.

I simply wrote my subjective opinion, which I think I have the right to do.
None of this invalidates your subjective opinions, which you are of course free to share. I just find it important to provide data to readers so that they can do their own research and make their own minds.
 
I agree with you, almost in all of what you write. As for the damping factor, it is quite a critical parameter, but of course it is not the only one.
Just to clarify my statements - I don't think the Amp Ultra is one of the best amplifiers in the world. There are absolutely amplifiers that are more powerful and/or which measure better across various metrics.

On the contrary, my opinion is that there's no such thing as "the best amplifier" - just amps that are suitable for a specific purpose, and those that aren't. In any case, audio performance is surely not the only factor that influences purchase decisions - and that is perfectly fine.
WiiM Amp Ultra is a nice package that will probably be a good fit in many cases, but definitely not in every imaginable case.

That all being said, the intention of my responses was just to point out that the WiiM Amp Ultra damping factor is not likely to be an issue, because it is high enough not to introduce significant frequency response deviation with complex loads.

There are of course amps with higher damping factors, but one has to ask when is the damping factor high enough? No amp has infinite damping factor, because real voltage sources can't have zero output impedance.

At this point it may be useful to link to this nice article by Benchmark (who seem to be proponents of very high damping factors, BTW), and this screenshot from their damping factor calculation spreadsheet:
DampingFactor-WithCables.png

As we can see, with 8Ohm nominal speaker, connected with 10ft of 11AWG wire, specific damping factor (DF) results in the following total frequency response (FR) errors:
  • DF >~25 results in FR error <1 dB
  • DF >50 results in FR error <0.5 dB
  • DF >125 results in FR error <0.25 dB
  • DF ~1000 is needed for the error to go below 0.1 dB
We can see how the relation is not linear, and how DF needs to increase disproportionately for progressively smaller improvements in frequency response error. E.g. if we look at DF=100 vs DF=1000 we see we're talking about an error difference of just 0.2dB for a DF that is one order of magnitude higher.

At this point I can suggest to readers to try and experiment with PEQ to get a sense of audibility of such low-level FR deviations - e.g. try listening with and without a -0.2dB PK PEQ filter at 150Hz with Q of let's say 0.7.

In case some find it interesting, in this old ASR post I wrote about damping factor and explained how it results in frequency response error due to simple frequency-dependent voltage division.

Another thing that is probably worth mentioning is that the frequency response error that is introduced by the amp-speaker impedance interaction (related to damping factor) can be completely corrected by EQ if one wishes to do so - though that would require first calculating or measuring the unique FR error, which is probably not trivial to do for most people. But again, considering the wider context of speaker response deviations and influence of room interaction, I don't believe this is really needed anyway.


None of this invalidates your subjective opinions, which you are of course free to share. I just find it important to provide data to readers so that they can do their own research and make their own minds.
I agree with you, almost in all of what you write. As for the damping factor, it is quite a critical parameter, but of course it is not the only one.
 
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