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Topping PA5 Review (Amplifier)

Heesung

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I've just received PA5!!!!

IMG_2233.jpg


SH*T.......
My xlr to trs converters don't fit...
Do they really have to be TRS...?
I just ordered other cables that I hope would fit.

...Just a couple more pics in case you are wondering how it looks...

IMG_2234.jpg
IMG_2235.jpg

IMG_2236.jpg


I wish I had ordered a silver version...
 
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amirm

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@amirm Is it possible to do a 18-19 khz test to see if there are any IMD.
I am not a fan of that test since both tones will be full amplitude at levels that are not remotely realistic.
 

pma

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I am not a fan of that test since both tones will be full amplitude at levels that are not remotely realistic.
Is this the reason not to perform one of the standard tests?? Again you bring your subjective opinion to objective measurements. It is just your opinion that HF linearity is not important. It is one of parameters to completely describe amplifier behaviour. When it is missing, it rises a question that something is going to be hidden, for some reason.
 

voodooless

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I am not a fan of that test since both tones will be full amplitude at levels that are not remotely realistic.
Why is the 32 tone test realistic then? It also has full scale output at high frequency? If it were to emulate music it should be sloping down into the high frequencies.

On the other side: how much different is the 32 tone test vs 18+19 kHz? Is there anything new to expect?
 
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Mulder

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I am not a fan of that test since both tones will be full amplitude at levels that are not remotely realistic.
Still, it is a sort of standard test and important for class D with it´s limited bandwidth measurements. Here Eigentakt has published 18-19 khz measurements. I would really like to see how this compares to Topping. https://purifi-audio.com/eigentakt/
 
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TNT

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Why is the 32 tone test realistic then? It also has full scale output at high frequency? If it were to emulate music it should be sloping down into the high frequencies.

On the other side: how much different is the 32 tone test vs 18+19 kHz? Is there anything new to expect?
No it isn't - each tone is lower in level to accommodate the "forest" of tones below clipping.

It just looks like all tones are "0 dB" - they are not.

//
 

voodooless

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No it isn't - each tone is lower in level to accommodate the "forest" of tones below clipping.

It just looks like all tones are "0 dB" - they are not.

//
Obviously you cannot have them full scale, but relative to each other they are still equal.
 

pma

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All those tests, 60Hz+7kHz, 250Hz+8kHz, 19kHz+20kHz and multitone make sense. It is a mistake to omit them for the reason of subjective opinion. There were more clever guys who came with those testing methods. Each of those test signals tests different behaviour of nonlinearity. Nonlinearity is not only level, but also frequency dependent.
 

Klint

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Can this unit put out more power if i only use 1 channel?
Thanks
 

Mulder

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I am not a fan of that test since both tones will be full amplitude at levels that are not remotely realistic.
I think that exactly the same argument regarding realism can be applied to measurements of SINAD and DACs. Why is it realistic to base a ranking on THD + N when all further improvements above a certain level cannot be heard by a human? Why would THD around 1 khz be more interesting or "ralistic" than IMD in the high registers? I suspect that the differences between class D amplifiers are about distortion in the upper registers. When measuring with a bandwidth limited to 40 khz, all measurements of IMD above 13-14 khz will be somewhat misleading. 18-19 khz is important to see how the amplifier behaves in the upper register.
 

DanielT

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Is this the reason not to perform one of the standard tests?? Again you bring your subjective opinion to objective measurements. It is just your opinion that HF linearity is not important. It is one of parameters to completely describe amplifier behaviour. When it is missing, it rises a question that something is going to be hidden, for some reason.
Does not John Atkinson perform IMD 19 + 20 kHz measurements?
 
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amirm

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Why is the 32 tone test realistic then?
Well, I resisted running that for a while as well. :) I started to do it because folks on the other side kept complaining that music has many tones and our testing only has one. Multitone with its 32 tones gets rid of that argument. It also provides a visual trend of distortion with frequency which dual tones do not.
 
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amirm

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I think that exactly the same argument regarding realism can be applied to measurements of SINAD and DACs. Why is it realistic to base a ranking on THD + N when all further improvements above a certain level cannot be heard by a human?
It is not the same argument. You are saying let's not measure at all because results don't matter. That goes counter to adding yet another measurement.
 
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amirm

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Why would THD around 1 khz be more interesting or "ralistic" than IMD in the high registers?
Because harmonics of 1 kHz tone land where our hearing is most sensitive and has the highest chances of being heard. 19+20 kHz does not at all represent that. There is just no argument for why it produces anything useful. Any perceptual analysis will nullify its value.
 
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amirm

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18-19 khz is important to see how the amplifier behaves in the upper register.
The spectral content there is some 40 to 60 dB lower than bass frequencies. You can't use the results of full amplitude and apply it there.
 

Mulder

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Because harmonics of 1 kHz tone land where our hearing is most sensitive and has the highest chances of being heard. 19+20 kHz does not at all represent that. There is just no argument for why it produces anything useful. Any perceptual analysis will nullify its value.
Our ears are much more sensetive to IMD than HD. There is of course a reason 18-19 khz is a standard test. Here is an example
264048319_10158801800409151_5840015736129042185_n.jpg
264048319_10158801800409151_5840015736129042185_n.jpg
 
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amirm

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That was really a strange conclusion of what I said
Well, the argument was strange. You don't want to diminish the value of measurements in one breath, and in the other say we should measure even more stuff that is even harder to show the value of.
 
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