Topping PA5 Review (Amplifier)

[ModDIY]

Hello guys,long lurker here,i did read a lot of this amp,i recently buyed a smsl sa300 but got a little bit roasted by some people I know,would this pa5 be better that the sa300? I would use it to drive a pair of open baffle speaker with 98 db of efficiency and maybe my klipschorns with 103 db of efficiency,what do you think about it? Should I give back the smsl sa300 and take this amplifier that i read is Soo good to be true?


And i forgot to add that i have a topping E30 for a DAC and I will need probably a trs to RCA cable

Keep your SA300 if the power is sufficient with your high efficiency loudspeakers.

 

[AudioArchitech]

Unfortunately I don't think your perception is wrong. It generally matches most Class D Amps subjective impressions for these possible reasons.

View attachment 182403


I am not intending to disparage the PA5 in any way as it actual design extracts the most out of the TPA32XX IC design layout. Kudos to topping for "Real World" implementation of this chipset.

Unfortunately it exposes the issue of SINAD being perceived as synonymous with "transparency" . What is more perplexing is why IMD tests and SINAD do not reveal this distortion above 5K.

View attachment 182414


Since the PA05 SINAD measures so close to the the Highly revered Benchmark AHB2 I will quote John Siau from https://www.audiosciencereview.com/...ements-of-benchmark-ahb2-amp.7628/post-180468

"Harmonic distortion may change the sound of a musical instrument long before we can recognize the fact that the music is distorted. The ratios of harmonics to the fundamental give each musical instrument its unique voice. Any time you add harmonic distortion, you make changes to this voicing."

Another test MISSING is the KEY test of Linear Phase Response.

I again quote John Siau regarding the Benchmark AHB2

"A non-linear phase response may be more audible than a non-linear frequency response. Errors in the phase response may create the impression that the frequency response is different. The frequency response of the AHB2 extends down to 0.1 HZ and up to 500 kHz so that the phase response is linear within the 20 Hz to 20 kHz audible band."

John Siau really summarizes Amplifier technology design issues in an easy palatable way. His posts on this forum are well worth a read.

Phase linearity and Harmonic Frequency distortion seems to be the "Achilles Heel" in Class-D implementations.
Phase Linearity is vital for proper soundstage and localization. Multichannel DSP uses Phase to localize. Actually your ears and brain do.
HYPEX Ncore and PURIFI foremost are diligently trying to address the 5khz to 20khz Harmonic/Phase linearity issues in Switching AMP design.
High bandwidth Amplifier design in the likes up to 3to600khz is specifically intended to do this to maintain Phase linearity. We as a whole take this for granted in Class A/B designs as a solved issue because it was 30-40 years ago.

I highly doubt the PA05 is transparent in audio in fact I would assert it colorizes high frequencies in different but similar way "tube" designs do.
There is a definite Harmonic frequency distortion above 5k being added. I call it harmonic eq that ads sizzle to say cymbals for example. But at the cost of disturbing timbre, vital localization phase cues and soundstage.
Speakers do this as well but constant directivity designs with time alignment are vastly improving transparency in audio production. The speaker variable is difficult enough, we do not need other devices in the signal path adding more anomalies.

I admittedly have tricked myself before loving the Class-D sound. Embarrassingly recommending it until I realized with much research with said Harmonic/Phase issues that I was doing the same thing as "tube" guys. I perceived it through my own subjective personal bias that this flavor was new and different so it must be better. I had one set of speakers that it really made shine. Since the components of these speakers were extremely high quality it HAD to be my signal chain that was lacking, so I thought...
At the same time, we are all entitled to colorize,DSP, eq and compensate for our inferior home listening environments to what we enjoy.
Speakers are still the weak link.

I myself was excited and about to purchase the PA05( I have a Topping D10s) because I have had great experience with SINAD thanks to this forum's efforts with DACS and headphone amps. The mission of ASR and Amirs work to bring clarity to the industry is to be applauded.

That said, I doubt in a ABX comparison the Topping PA5 would sound the same as an Benchmark AHB2. I haven't even addressed dynamic transient capabilities like high current designs.

This however strikes at the core of the significance of SINAD value as representing "State of the Art" designs. It seems we need SINAD + phase linearity response test and emphasis on Frequency distortion or at least specifically for Class-D designs. Even DAC's output filters could have Phase linearity issues.

Lets just not equate the Topping PA5 and especially 105db SINAD as a representation of "transparent". Hiss free yes!

I am not trying to Disparage Topping, It just shows that if you give a spec like SINAD high value, Someone will design a device to match that.

So what Tests combined with SINAD will show Transparency?

It seems we need a SINAD+* now.


Thanks AudioArchitech for taking a bullet for us and being candid with your impression. Not letting your logic brain and a tech spec warrior mentality bias your impressions. My budget for the PA5 will be shifted towards maybe the EX5 or Gustard X16.

J-Sine

Thanks J-Sine for this well written post. That Benchmark AHB2 would be nice, one day it will be mine. This PA5 has a lot going for it, most of the time it sounds really great. Sometimes, something sounds off to me but I am also comparing it to more expensive amps, Class AB designs...

 

[Ciobi69]

Keep your SA300 if the power is sufficient with your high efficiency loudspeakers.

Thanks i did get a little bit demotivated at the start,but i think it's a valid product

 

[SaltyCDogg]

Thanks i did get a little bit demotivated at the start,but i think it's a valid product

I like my SA300, tried it with a couple of different bookshelf speakers (including some modern Klipsch) and some floorstanders, all in small British rooms, but still

 

[antcollinet]

......What is more perplexing is why IMD tests and SINAD do not reveal this distortion above 5K.

Because distortion above 10K is supersonic ultrasonic . What the multitone test shows is (at least at 5W) that higher frequency distortion is largely above 20KHz, even including IMD products folding back into the audible spectrum.

 

[georgeT]

Another test MISSING is the KEY test of Linear Phase Response.

I again quote John Siau regarding the Benchmark AHB2

"A non-linear phase response may be more audible than a non-linear frequency response. Errors in the phase response may create the impression that the frequency response is different. The frequency response of the AHB2 extends down to 0.1 HZ and up to 500 kHz so that the phase response is linear within the 20 Hz to 20 kHz audible band."

John Siau really summarizes Amplifier technology design issues in an easy palatable way. His posts on this forum are well worth a read.

Phase linearity and Harmonic Frequency distortion seems to be the "Achilles Heel" in Class-D implementations.
Phase Linearity is vital for proper soundstage and localization. Multichannel DSP uses Phase to localize. Actually your ears and brain do.
HYPEX Ncore and PURIFI foremost are diligently trying to address the 5khz to 20khz Harmonic/Phase linearity issues in Switching AMP design.
High bandwidth Amplifier design in the likes up to 3to600khz is specifically intended to do this to maintain Phase linearity. We as a whole take this for granted in Class A/B designs as a solved issue because it was 30-40 years ago.

Your reference is a person who just happens to sell equipment marketed as having low phase distortion. At no point did you or him reference a study backing the claims on the audabilty of phase distortion at high frequencies.

 

[Mulder]

Because distortion above 10K is supersonic ultrasonic . What the multitone test shows is (at least at 5W) that higher frequency distortion is largely above 20KHz, even including IMD products folding back into the audible spectrum.

As I understand it, with a 40 khz filter as used by Amirm when measuring class D, everything IMD above about 13.khz are filtered out.

 

[ModDIY]

I like my SA300, tried it with a couple of different bookshelf speakers (including some modern Klipsch) and some floorstanders, all in small British rooms, but still

I own the Sabaj A20a and am also completely satisfied.

 

[Ciobi69]

I own the Sabaj A20a and am also completely satisfied.

glad to know guys thanks!

 

[AudioArchitech]

I think for many people, this PA5 will be great. I have high end, revealing speakers (maybe too revealing) and they show this amp's weaknesses at that level. I was hoping for a $450 (CAD) giant killer and it didn't work out for me but this is still a great little amp. I just did another A/B comparison with Aiyima A08 and the PA5 is certainly better than A08 in my system. I'll sell it and get something else. Some ideas: Parasound 275V2, Emotiva BasX A2, Buckeye or Audiophonics NC252MP, IOTAVX PA3. Or maybe just get another Audiolab 6000A? Any other ideas? looking for best bang for buck.

 

[Gio]

I am so happy about this analysis because it proves to myself I am not crazy. I was super excited with my PA5 but I really didn’t like the sound of it compared to my VTV Purifi EVAL-1 and I couldn’t pin point why but your explanation really matches my subjective listening experience.

I really love when science makes sense. Unfortunately our senses are extremely complex and one single magic number like SINAD cannot represent everything related to pure sound reproduction… It’s just not that simple (as it never is)…

Your reference is a person who just happens to sell equipment marketed as having low phase distortion. At no point did you or him reference a study backing the claims on the audabilty of phase distortion at high frequencies.

I think for many people, this PA5 will be great. I have high end, revealing speakers (maybe too revealing) and they show this amp's weaknesses at that level. I was hoping for a $450 (CAD) giant killer and it didn't work out for me but this is still a great little amp. I just did another A/B comparison with Aiyima A08 and the PA5 is certainly better than A08 in my system. I'll sell it and get something else. Some ideas: Parasound 275V2, Emotiva BasX A2, Buckeye or Audiophonics NC252MP, IOTAVX PA3. Or maybe just get another Audiolab 6000A? Any other ideas? looking for best bang for buck.

I would suggest instead just to liste to music

 

[AudioArchitech]

Thanks, that was so valuable and helpful ; )

 

[Matias]

Unfortunately I don't think your perception is wrong. It generally matches most Class D Amps subjective impressions for these possible reasons.

View attachment 182403


I am not intending to disparage the PA5 in any way as it actual design extracts the most out of the TPA32XX IC design layout. Kudos to topping for "Real World" implementation of this chipset.

Unfortunately it exposes the issue of SINAD being perceived as synonymous with "transparency" . What is more perplexing is why IMD tests and SINAD do not reveal this distortion above 5K.

View attachment 182414


Since the PA05 SINAD measures so close to the the Highly revered Benchmark AHB2 I will quote John Siau from https://www.audiosciencereview.com/...ements-of-benchmark-ahb2-amp.7628/post-180468

"Harmonic distortion may change the sound of a musical instrument long before we can recognize the fact that the music is distorted. The ratios of harmonics to the fundamental give each musical instrument its unique voice. Any time you add harmonic distortion, you make changes to this voicing."

Another test MISSING is the KEY test of Linear Phase Response.

I again quote John Siau regarding the Benchmark AHB2

"A non-linear phase response may be more audible than a non-linear frequency response. Errors in the phase response may create the impression that the frequency response is different. The frequency response of the AHB2 extends down to 0.1 HZ and up to 500 kHz so that the phase response is linear within the 20 Hz to 20 kHz audible band."

John Siau really summarizes Amplifier technology design issues in an easy palatable way. His posts on this forum are well worth a read.

Phase linearity and Harmonic Frequency distortion seems to be the "Achilles Heel" in Class-D implementations.
Phase Linearity is vital for proper soundstage and localization. Multichannel DSP uses Phase to localize. Actually your ears and brain do.
HYPEX Ncore and PURIFI foremost are diligently trying to address the 5khz to 20khz Harmonic/Phase linearity issues in Switching AMP design.
High bandwidth Amplifier design in the likes up to 3to600khz is specifically intended to do this to maintain Phase linearity. We as a whole take this for granted in Class A/B designs as a solved issue because it was 30-40 years ago.

I highly doubt the PA05 is transparent in audio in fact I would assert it colorizes high frequencies in different but similar way "tube" designs do.
There is a definite Harmonic frequency distortion above 5k being added. I call it harmonic eq that ads sizzle to say cymbals for example. But at the cost of disturbing timbre, vital localization phase cues and soundstage.
Speakers do this as well but constant directivity designs with time alignment are vastly improving transparency in audio production. The speaker variable is difficult enough, we do not need other devices in the signal path adding more anomalies.

I admittedly have tricked myself before loving the Class-D sound. Embarrassingly recommending it until I realized with much research with said Harmonic/Phase issues that I was doing the same thing as "tube" guys. I perceived it through my own subjective personal bias that this flavor was new and different so it must be better. I had one set of speakers that it really made shine. Since the components of these speakers were extremely high quality it HAD to be my signal chain that was lacking, so I thought...
At the same time, we are all entitled to colorize,DSP, eq and compensate for our inferior home listening environments to what we enjoy.
Speakers are still the weak link.

I myself was excited and about to purchase the PA05( I have a Topping D10s) because I have had great experience with SINAD thanks to this forum's efforts with DACS and headphone amps. The mission of ASR and Amirs work to bring clarity to the industry is to be applauded.

That said, I doubt in a ABX comparison the Topping PA5 would sound the same as an Benchmark AHB2. I haven't even addressed dynamic transient capabilities like high current designs.

This however strikes at the core of the significance of SINAD value as representing "State of the Art" designs. It seems we need SINAD + phase linearity response test and emphasis on Frequency distortion or at least specifically for Class-D designs. Even DAC's output filters could have Phase linearity issues.

Lets just not equate the Topping PA5 and especially 105db SINAD as a representation of "transparent". Hiss free yes!

I am not trying to Disparage Topping, It just shows that if you give a spec like SINAD high value, Someone will design a device to match that.

So what Tests combined with SINAD will show Transparency?

It seems we need a SINAD+* now.


Thanks AudioArchitech for taking a bullet for us and being candid with your impression. Not letting your logic brain and a tech spec warrior mentality bias your impressions. My budget for the PA5 will be shifted towards maybe the EX5 or Gustard X16.

J-Sine

If you are worried about phase, have you seen the step response for your speakers?

 

[Andrej]

I think for many people, this PA5 will be great. I have high end, revealing speakers (maybe too revealing) and they show this amp's weaknesses at that level. I was hoping for a $450 (CAD) giant killer and it didn't work out for me but this is still a great little amp. I just did another A/B comparison with Aiyima A08 and the PA5 is certainly better than A08 in my system. I'll sell it and get something else. Some ideas: Parasound 275V2, Emotiva BasX A2, Buckeye or Audiophonics NC252MP, IOTAVX PA3. Or maybe just get another Audiolab 6000A? Any other ideas? looking for best bang for buck.

There is a common issue that I do not think anybody has clearly (and comprehensively) stated yet (I may well be wrong).
1. One metric for evaluation is - Fidelity. Is it accurately conveying what was on the recording. Measurements help here.
2. Second is - Taste. I may or may not like what was on the recording. Which is why many recordings add synthetic reverb, for example, to make it more likeable. Products that add their own sound might make the recording (more often than not, one hopes) appear more enjoyable
3. Subjective evaluation (personal preference) is only meaningful if any biases are removed, ie. it needs to be double blind and in statistically meaningful numbers

Of course nobody is being forced to follow No. 3 in ascertaining No. 2, but it will be meaningless otherwise. Certainly to everybody else, but I am making a point here that it is meaningless to the person doing the "evaluation" too.

So if you do not like PA5, so be it, choose what makes you happy.
I am just suggesting that perhaps you should try following the principles of No. 1. and No. 2. if you ever want to get to a consistent conclusion.

Hopefully you already did that!

Always assuming that the equipment is used within their operating parameters

Additionally, we tend to like what is familiar to us. It is worth doing comparisons in both directions, after getting used to one piece of equipment, and then swapping them, getting used to the other piece of equipment and then doing the comparison again (still following the methodology of No. 2!).

 

[AudioArchitech]

I would also suggest avoiding confirmation bias.

I'm just sharing a story. I appreciate measurements, subjective reviews and other feedback so I am just posting my experience in case it interests some. Obviously, not all want to hear it.

After all the measurements and testing, my ears are the final measurement. PA5 is great, but I will try something else. PM me if you want to buy it. I'm in CANADA.

 

[wjp007]

Currently yes I am running a R and L sub, and it works just fine, even though it's not optimal. That will change when I get the flex.

I'm replacing my current DAC with the Flex since it fits my use case perfectly. I can see where if you wanted to keep your DAC, it may not be as ideal. The diagram below will be my setup once the Flex gets here. Now I just have a normal DAC where the Flex is shown, along with the filters going into the PA5 and a crossover set on the Crown amp, as well as no balanced connections, and stereo subs:

View attachment 178882

Did you get your Flex yet? If so, how is working out for your. I got a Minidsp 2x4HD and use it as the DAC and crossover. I’m not really happy with it. It doesn’t sound as clean as my other setup which was DAC to old preamp to PA5.

 

[gfinlays]

What do guys think of the soundstage and imaging? I still need to compare, maybe it's the PecanPi... but I find the center imaging is not as good.

The soundstage and imaging with the PA5 into the ZRTs is superb. In fact, better than my DK. The DK has an analogue volume control and there are subtle variations in channel balance (probably +/- 0.5dB) depending on where the volume knob is. This affects centre vocal positioning/soundstage. With the PA5, the channel balance is perfect, so soundstage positioning is more precise.

 

[gfinlays]

Speaker drive unit break-in only takes a few hours at most and it's woofers and midwoofers only. The suspension needs a little time to reach full compliance and during break-in, T/S parameters can change by as much as 10 - 15%. I read a really interesting article the other day with comments from some of the major drive unit manufacturers (e.g. ScanSpeak, Tymphany, ATC etc.) and their views on drive unit break in. I can't link it here at the moment as apparently the domain expired yesterday.

Apparently, the domain has been renewed and the site is up and running again

Matrix-Hifi: Speakers Burn In

 

[AudioArchitech]

Humm... curious. I have a Topping E30 DAC. Not Balanced, but will have to do for the test. I had better soundstage and imaging with E30 in previous setups. Hard to believe that it could be the PecanPi, we shall see.

Thanks for feedback

 

[gfinlays]

Your reference is a person who just happens to sell equipment marketed as having low phase distortion. At no point did you or him reference a study backing the claims on the audabilty of phase distortion at high frequencies.

Indeed. I also read the article regarding their blind A/B/X comparison between a class A/B amp and the Benchmark AHB2:

Power Amplifiers - A "First Watt" ABX Test

In Benchmark's listening room we recently demonstrated the importance of the first watt using two 100 watt stereo power amplifiers. One amplifier was a traditional class-AB amplifier, the other was Benchmark's AHB2 power amplifier with feed-forward error correction. Using a double-blind ABX...

benchmarkmedia.com

The Class A/B amp under test is obviously either badly designed or the output stage bias is woefully inadequate.

Interestingly, when Stereophile tested the DK Design VS.1 Reference MK.III (the model down from mine), they found evidence of a lack of bias in the output stage:

DK Designs VS.1 Reference Mk.III integrated amplifier Measurements

Sidebar 3: Measurements Before performing any measurements on it, I preconditioned the DK Designs VS.1 Reference Mk.III by running it at 50Wpc (one-third the specified power) with both channels driven into 8 ohms for 60 minutes. The THD+noise remained at a highish 0.2% throughout this period...

www.stereophile.com

Sanken recommend minimum 40mA bias on the SAP15 Darlington output trannies - https://datasheetspdf.com/pdf-file/274943/Sankenelectric/SAP15/1

I run mine at ~100mA bias. This might explain why my amp chews 90W when switched on and doing nothing (though I expect the dual mono toroidal power transformers probably take up a fair chunk of that!)