Why do Topping PA5II and Aiyima A70 Monos sound so different?

[Halbknapp]

I noticed some time ago that my Topping PA5II (and Plus as well) sound somewhat bright and brings out mid frequency more than most other Amps.
Aiyima A70 Monos i recently purchased sound rather laid back with more recessed vocals. Other Amps as well sound different but these use the same Chip and PFFB each.

I am not even one that would expect Amps to sound different at all but i could very easily pick them blind and at a different time (with same speakers at same position).
Measuring the speakers acustically there is no difference i could measure in Frequency response or distortion. So why do i hear a difference that would otherwise only come with a noticable difference in frequency response?

 

[staticV3]

Placebo.

If you'd like, try recording a snippet of music with each Amp (fixed microphone position!), then upload the clips here so we can take a listen.

If there's no difference in those, then it's 100% in your imagination.

 

[Halbknapp]

Seeing Amirs recent testing of the Aiyima A70 Monos I wonder if the difference in Tonality is from IMD in the lower frequencies. Anyway the Aiyimas will go back to Amazon.

 

[3eaudio]

1. they are different chip(PA5 use TPA3251)
2. FPPB implementation not the same exactly

 

[BDWoody]

my Topping PA5II (and Plus as well) sound somewhat bright and brings out mid frequency more than most other Amps.
Aiyima A70 Monos i recently purchased sound rather laid back with more recessed vocals.

1. they are different chip(PA5 use TPA3251)
2. FPPB implementation not the same exactly

You believe that's the explanation?

 

[DSJR]

I still firmly believe that if a difference really *can* be heard, then it's certainly measurable and a null test should also show the difference signal. Sighted hearing does bring in so many variables, it's difficult to isolate the hearing part (I've found in the past when I bothered about such things). I may be returning to some rather old and more physically 'delicate' speakers and if that happens successfully, I may well return to my serviced but old HH VX300 power amp, as there's a claimed substantial sub 20Hz filter on the input which may help protect the bass drivers a little from 'popping' on cleanly recorded kick drums for example. Heck, they even put basic specs on the top panel too (less than 0.03& IMD isn't that wonderful though, but audible?). It's a solid lump though...

 

[3eaudio]

You believe that's the explanation?

user experience is another story but technically should be as a basic line.

 

[tmtomh]

My first question would be how, or if, the volume was matched in the comparisons.

 

[Halbknapp]

My first question would be how, or if, the volume was matched in the comparisons.

In my specific case no. I changed volume up and down to see (or hear) if Tonality would change with volume (which it did not seem to do too much

 

[Guddu]

2. FPPB implementation not the same exactly

I believe you meant PFFB.

Is 3e’s A5 has different PFFB deployment than PA5/PA5II in basic term?

 

[DVDdoug]

One of the amps could be broken but that's highly unlikely.

sound rather laid back

Nobody knows what that means.

with more recessed vocals.

Again highly unlikely to happen accidently. There is a particular defect that can make a "center channel vocal remover". It will kill everything in the center, including the bass which is centered. It also kills the stereo. If you unplug one channel the sound will come-out of both speakers and the bass & vocals will come back. If you did mono measurements (or if you otherwise have a mono signal) you'd measure almost nothing since everything is in the phantom center and canceled.

i could very easily pick them blind and at a different time (with same speakers at same position).

But you didn't... And you didn't measure a difference. What is a blind ABX test?

Audiophoolery

 

[Guddu]

I noticed some time ago that my Topping PA5II (and Plus as well) sound somewhat bright and brings out mid frequency more than most other Amps.
Aiyima A70 Monos i recently purchased sound rather laid back with more recessed vocals. Other Amps as well sound different but these use the same Chip and PFFB each.

I am not even one that would expect Amps to sound different at all but i could very easily pick them blind and at a different time (with same speakers at same position).
Measuring the speakers acustically there is no difference i could measure in Frequency response or distortion. So why do i hear a difference that would otherwise only come with a noticable difference in frequency response?

The IMD measurements in Amirm’s post clearly indicate that it’s not superior in that matter compared to some others, but I can confidently say that A70 mono has smooth non-fatiguing character. I have these hooked up with Ascend Sierra-lx from last 3 weeks, while my daily driver in same setup is PA7.

I am willing to try understanding the IMD impact on this amplifier as I have a pair.
Many might say that this IMD is more likely inaudible, but can anyone suggest specific tests that could clearly show me it’s impact in audible way?

 

[Halbknapp]

The IMD measurements in Amirm’s post clearly indicate that it’s not superior in that matter compared to some others, but I can confidently say that A70 mono has smooth non-fatiguing character. I have these hooked up with Ascend Sierra-lx from last 3 weeks, while my daily driver in same setup is PA7.

I am willing to try understanding the IMD impact on this amplifier as I have a pair.
Many might say that this IMD is more likely inaudible, but can anyone suggest specific tests that could clearly show me it’s impact in audible way?

It seems you describe the same thing - this smooth non fatigueing sound character. At the Very least one could say that the Aiyima A70 Monos have this attribute much more then the Topping (of which I assume PA5II to be somewhat similar to a PA7 other then less power). However in my case I like the less laid back Topping sound more.

 

[GXAlan]

Microphone is the best solution. If you must, use the iPhone microphone.

You are asking why. We can answer it once you record your home setup.

Amplifiers behave differently into real world loads compared to non inductive resistors. These lead to frequency response irregularities which can be measured. It is possible that the FR irregularity is non linear which is where recording music rather than a sweep is helpful.

 

[tmtomh]

In my specific case no. I changed volume up and down to see (or hear) if Tonality would change with volume (which it did not seem to do too much

Thanks! In that case I’d hypothesize that it’s unlikely the comparisons were made at closely matched volumes when using the three different amps. Comparing at various volumes is fine of course - it’s that for each different volume level all three amps should be listened to at that same level.

 

[Guddu]

Microphone is the best solution. If you must, use the iPhone microphone.

You are asking why. We can answer it once you record your home setup.

Amplifiers behave differently into real world loads compared to non inductive resistors. These lead to frequency response irregularities which can be measured. It is possible that the FR irregularity is non linear which is where recording music rather than a sweep is helpful.

I quite frequently take REW measurements when I change my amplifier, I have been doing this for all these tpa3255 amplifier’s like Fosi ZA3, V3 mono, Topping PA5II, PA7, Aiyima A07 pro, A07 max, A70 and now with A70 mono.
Sometimes I have seen some differences, minor or major, and if I do then I capture it in my “User Impressions & Owner’s” posts.
In this specific case, I have compared REW sweep many times between PA7 and A70 mono with a few different speakers and haven’t seen any real differences.

 

[GXAlan]

In this specific case, I have compared REW sweep many times between PA7 and A70 mono with a few different speakers and haven’t seen any real differences.

Agreed. It’s hard to show differences.

Integrated Amplifier Comparison: $90 vs $9000

I continue to hear differences between amplifiers that might be expected to be inaudibly different. That is, for two high-SINAD systems that I'm not running into clipping, I hear differences. I also believe in measurements. My perspective has been consistent: "Everything that can be measured...

www.audiosciencereview.com

But if you can show differences, it becomes possible that the differences are audible.

I genuinely believe that amplifiers sound different. I believe that “big” differences are actually very subtle and those changes fade with time as you get used to it. The ability for one comparison to generate an ASMR tingle is one example. I gave ABX’d CD vs SACD, gotten perfect results because only one of the two gave me tingles. But after the first day, neither gives me that ASMR tingle again so I can no longer discern the two even though I saw it day one.

While it is academic and fun to try to prove that amplifiers can sound different, speakers clearly sound different and I have moved to Meyer Sound which is all Class D active speakers currently.

Edit: Any time I have heard differences between amps, I have been able to measure it through a frequency response difference which can be unexpected from resistor based measurements. Even when I hear differences, it is vanishingly small and rare. My official recommendation remains: spend as much as possible on the room/house. Then speakers.