# Topping PA3s Review (Desktop Amplifier)

#### Walter

##### Addicted to Fun and Learning
Joke… obviously not very good one, considering 6,000 watts already!
I got it right away and thought it was pretty good!

#### FTB

##### Member
Hello @amirm

I have a question here, sorry if it has been already asked (I can't always fully read a 18 pages topic as english isn't my native langage).

On this graph the THD+N is kinda 79 dB @ 1w @ 1 KHz @ 4 Ohm (that could fit my needs) :

On this graph, THD+N is now 66 dB @ 1w @ 1 KHz @ 4 Ohm (not good enough to me)

Do I miss something ?
I'm asking as this little amp could fit all my need in a budget system (plus looks good) except the distortion values on this second graph.

Grazie

Last edited:

#### NTK

##### Major Contributor
Forum Donor
Hello @amirm

I have a question here, sorry if it has been already asked (I can't always fully read a 18 pages topic as english isn't my native langage).

On this graph the THD+N is kinda 79 dB @ 1w @ 1 KHz @ 4 Ohm (that could fit my needs) :

On this graph, THD+N is now 66 dB @ 1w @ 1 KHz @ 4 Ohm (not good enough to me)

Do I miss something ?
I'm asking as this little amp could fit all my need in a budget system (plus looks good) except the distortion values on this second graph.

Grazie
The difference is in the measurement bandwidths. The upper graph is 20 kHz and the lower graph is 45 kHz.

Using the IEC definition which Amir's Audio Precision analyzer uses, THD+N (also known as SINAD) is calculated as the total energy in all frequency bands in the measured signal except the test signal, divided by the total energy in the entire measured signal (including the test signal).

If the measurement bandwidth is only to 20 kHz, all the energy in the noise and harmonic distortions above 20 kHz is excluded. That is why the 45 kHz bandwidth measurement is worse, as the additional energy in the 20 - 45 kHz range is included in the calculation.

The 20 kHz bandwidth THD+N number is usually the one that is used in specifications and comparisons, as the generally accepted audible frequency range stops at 20 kHz.

#### FTB

##### Member
All clear, thank you !

Out of curiosity, can't the THD+N graph at different frequencies be done in a 20Khz BW ?
I get the fact we do a mean measure at 1Khz but it is very instructive to see distortion values at other frequencies without messing it up because BW extended to a non useful 45 Khz.

#### Laughing Rabbit

##### Member
Forum Donor
This is a review and detailed measurements of the Topping PA3s balanced integrated power amplifier. It was sent to me by the company. It is not announced yet and I forgot to ask how much it will cost. It is in similar form factor to PA3 which I reviewed before and that one cost \$120.

I think Topping has really nailed the look of budget desktop products in this style, bringing some much needed elegance to the design:

View attachment 156814

Even the power/input selector feels elegant to touch with a reassuring relay click.

And yes, there is balanced input now in the form of TRS connectors which is very common in Pro space:

View attachment 156815

As noted, you can actually select between them so you have dual inputs, albeit, in different formats (balanced and unbalanced).

As you see, a rather large and high current external power supply is provided which likely sets the limit of how much it can output. Unlike other budget amps in this class, it is branded by Topping and safety certifications seem legit.

In use, the amplifier ran cool and at room temperature even after all of my tests. Its protection circuit never intruded and the amp was comfortable being pushed well into clipping with no shut down, etc.

Topping PA3s Measurements
I performed all of my testing using balanced inputs. Here is our usual dashboard:

View attachment 156827

SINAD which represents sum of distortion and noise is well above average for all amplifiers tested let alone budget ones:

View attachment 156817

Company specifications is 0.0045% which is basically what I achieved.

Teasing out noise versus distortion, we see that this is a very quiet amplifier:

View attachment 156818

Achieving full 16 bit dynamic range is very difficult for most amplifiers and PA3s delivers on that. Part of the reason for good performance here is that the amplifier gain is lower than what is common at 20 dB. This is actually fine though as full power can be achieved at under 2 volts with balanced input which any desktop DAC can produce. So might as well put that higher input voltage to good use and improve amplifier noise performance.

I am always nervous running frequency response tests on class D amplifiers, worried that they should have variations at high frequencies. The PA3s put my worries aside:

View attachment 156819

Seems like the output filter is inside the feedback loop which is nice.

Crosstalk performance is above average:

View attachment 156828

Multitone shows 17 bits of distortion-free range across full audible band:

View attachment 156829

Let's get into power measurements starting with 4 ohm load:

View attachment 156822

Ah, this is on the low side and gets (naturally) lower at 8 ohm:

View attachment 156823

Allowing for more distortion at 4 ohm gives a bit more power:

View attachment 156824

So no competition for larger amplifiers.

Varying the frequency shows fair bit of ups and downs:

View attachment 156825

Finally, out of band switching noise is kept low although its baseline is higher than I expected:

View attachment 156826

Conclusions
Up until now, I have not been a fan of Topping power (speaker) amplifiers. Their performance was simply not that good. With the advent of new chip-based amplifiers with better performance, Topping had fallen behind even more. Here, it seems they have taken a standard platform and really optimize it as they do with their DACs. This shows in very low noise level, nice crosstalk and excellent frequency response. My only miss is the amount of power available if you were to use this for main hi-fi system.

Overall, I am happy to recommend the Topping PA3s amplifier. Welcome to the games Topping!

-----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
I notice it's called 'integrated amp' in line 1. But looks like a 'power amp'. Would this be OK to plug my SoundBlaster AE-7 card directly into? Or is a 'pre-amp' needed? This is just for my desktop sound, I've got some old Infinity reference 1 bookshelves...Thanks again, Amir.

#### musiclover

##### Member
I notice it's called 'integrated amp' in line 1. But looks like a 'power amp'. Would this be OK to plug my SoundBlaster AE-7 card directly into? Or is a 'pre-amp' needed? This is just for my desktop sound, I've got some old Infinity reference 1 bookshelves...Thanks again, Amir.
It's definitely an integrated amp, as you can see by the rotary volume control it has (so a pre-amp is already included, hence 'integrated'). A power amp does not have volume control. So yes, you can plug your SoundBlaster AE-7 directly into this amp's single-ended input.

By the way, theoretically you could plug your sound card directly into a power amp as well, you'd just need to control the volume via your computer's operating system (Windows), which is not desirable though.

Forum Donor

#### tvrgeek

##### Major Contributor
More power? Well buy a bigger amp! This is one of a very few that is small enough for what I want on my desk. Poor? It cost less than a decent dinner for crying out loud. Want a March? They cost 5 times as much. Perspective folks. Perspective.

What I can't find is a clean 20 or 30W DAC-pre-power-phones to replace my old Tripath. I don't want a stack, I want a box.

#### Walter

##### Addicted to Fun and Learning
More power? Well buy a bigger amp! This is one of a very few that is small enough for what I want on my desk. Poor? It cost less than a decent dinner for crying out loud. Want a March? They cost 5 times as much. Perspective folks. Perspective.

What I can't find is a clean 20 or 30W DAC-pre-power-phones to replace my old Tripath. I don't want a stack, I want a box.
Loxjie A30 (poor HP)? Topping MX5 (awaiting measurements)?

#### sjeesjie

##### Active Member
I just got the PA3s and I’m amazed about it! It’s beautifully small and matches the DX3pro, very nice!
The only thing that bothers me a bit is the leakage of current that you can feel through touching them. Oh and the blue led

#### TurtlePaul

##### Senior Member
Forum Donor
All clear, thank you !

Out of curiosity, can't the THD+N graph at different frequencies be done in a 20Khz BW ?
I get the fact we do a mean measure at 1Khz but it is very instructive to see distortion values at other frequencies without messing it up because BW extended to a non useful 45 Khz.
I see that nobody ever answered this. I will answer for posterity even though this is now an old question.

No, you can't run the multifrequency at 20 kHz bandwidth and here is why:

The most interesting aspect of this test on class-D amps is often the performance vs. frequency as the frequency increases towards the amps low pass filter. You can see the worst performing lines are the 10 kHz and 15 kHz lines because as frequency increases it becomes harder for class D amps to remain well behaved.

What happens when you apply a 20 Khz filter? Now the 10 kHz line becomes a measure of the output filter because to second harmonic (the lowest frequency with distortion) is at the filter frequency. The 15 kHz tone suddenly measures perfectly because the H2 (30 kHz) and H3 (45 kHz) are above the filter frequency. That is why the bandwidth is broadened for the frequency test.

FTB

#### tonycollinet

##### Major Contributor
I see that nobody ever answered this. I will answer for posterity even though this is now an old question.

No, you can't run the multifrequency at 20 kHz bandwidth and here is why:

The most interesting aspect of this test on class-D amps is often the performance vs. frequency as the frequency increases towards the amps low pass filter. You can see the worst performing lines are the 10 kHz and 15 kHz lines because as frequency increases it becomes harder for class D amps to remain well behaved.

What happens when you apply a 20 Khz filter? Now the 10 kHz line becomes a measure of the output filter because to second harmonic (the lowest frequency with distortion) is at the filter frequency. The 15 kHz tone suddenly measures perfectly because the H2 (30 kHz) and H3 (45 kHz) are above the filter frequency. That is why the bandwidth is broadened for the frequency test.
Correct - but I think the purpose of the question is:

Why does it matter that 10KHz+ distorts more than lower frequencies if the distortion products are ultrasonic and therefore inaudible. IE, I think FTB would like to see a graph that shows only audible distortion.

#### TurtlePaul

##### Senior Member
Forum Donor
Correct - but I think the purpose of the question is:

Why does it matter that 10KHz+ distorts more than lower frequencies if the distortion products are ultrasonic and therefore inaudible. IE, I think FTB would like to see a graph that shows only audible distortion.
It is nice to know if your class D amp is a tweeter heater - ultimately a lot of that 20 - 45 kHz power ends up disipated in the tweeter voice coil. Admitedly, at these distortion figures the tweeter power and intermodular distortion will be low.

On another note, I wish there was a cheap <\$200 chip amp that achieved this performance with a single ended platform. If I read the specs correctly, half of the power drops off if you use RCA instead of XLR. I would imagine that a lot of people looking at this price point have single ended connections throughout their chain.

#### howard416

##### Active Member
It is nice to know if your class D amp is a tweeter heater - ultimately a lot of that 20 - 45 kHz power ends up disipated in the tweeter voice coil. Admitedly, at these distortion figures the tweeter power and intermodular distortion will be low.

On another note, I wish there was a cheap <\$200 chip amp that achieved this performance with a single ended platform. If I read the specs correctly, half of the power drops off if you use RCA instead of XLR. I would imagine that a lot of people looking at this price point have single ended connections throughout their chain.
Found this recently, seem to have come out of nowhere but no complaints yet. Obviously not a turnkey solution though.

#### FTB

##### Member
I see that nobody ever answered this. I will answer for posterity even though this is now an old question.

No, you can't run the multifrequency at 20 kHz bandwidth and here is why:

The most interesting aspect of this test on class-D amps is often the performance vs. frequency as the frequency increases towards the amps low pass filter. You can see the worst performing lines are the 10 kHz and 15 kHz lines because as frequency increases it becomes harder for class D amps to remain well behaved.

What happens when you apply a 20 Khz filter? Now the 10 kHz line becomes a measure of the output filter because to second harmonic (the lowest frequency with distortion) is at the filter frequency. The 15 kHz tone suddenly measures perfectly because the H2 (30 kHz) and H3 (45 kHz) are above the filter frequency. That is why the bandwidth is broadened for the frequency test.
Thank you

#### Jhify

##### Member
I just got one for my bedroom setup. It replaces a pm7003. So far so good, it sounds great and transparent. It's got enough power to shake the walls of my 12 square meters bedroom, I'd need to stick the tweeter into my eardrums to hear any noise floor. It consumes such little power I can leave it always on and forget about it in the closet. All that for 150. What a time we live in.

#### Lorenzo78

##### Member
Hi all, I'm new here, from Italy

I have a PA3S amplifier, using it with my Topping E30 DAC and I noticed the max out level is not always satisfying : with low registration (ex. some classical records) the volume of the PAS3S doesn't allow for getting a decent level of SPL. Too low decibel out through my speakers, even at the highest volume level (speakers are DALI ZENSOR 1)

I read the input sensitivity of PA3S is 0,92 Vrms with a gain of 25.2 db on the SE IN, but in the BALANCED Input, the sensitivity is 1,75 Vrms and gain 19.5.

Will I get more SPL and volume (more output db) with TOPPING D10 BALANCED DAC? Topping D10 balanced has out level of: 4.2Vrms @0dBFS (TPDZ specs).
Am I the only one who detects this low volume using the SE input of the PA3S? Apart from the output volume level which doesn't always satisfy me, the sound is very good.

#### TurtlePaul

##### Senior Member
Forum Donor
Will I get more SPL and volume (more output db) with TOPPING D10 BALANCED DAC? Topping D10 balanced has out level of: 4.2Vrms @0dBFS (TPDZ specs).
Am I the only one who detects this low volume using the SE input of the PA3S?
4V at +19.5 dB is the same volume as 2V at +25.5 dB.

Those Dali dont lack sensitivity. Are you sure volume is max on your PC, E30 and PA3?

#### Lorenzo78

##### Member
4V at +19.5 dB is the same volume as 2V at +25.5 dB.

Those Dali dont lack sensitivity. Are you sure volume is max on your PC, E30 and PA3?
Thank you Paul. Yes, volume is at max level on each.. PC, E30, PA3s. By comparison I can get more SPL with my sure TA2024, it can be louder with the same low level record (a lot of classical music, for instance). No noticeable distortion, despite the low power of the TA2024.

Obviously when the record is high (most of rock / pop music), the PA3s allow the get more undistorted power, with good results.
But my "issue" is.. to amplify and listen records that are registered not so high, and the PA3s seems to have the "handbrake on".

#### somebodyelse

##### Major Contributor
Which Sure TA2024? According to Sure's AS32157 datasheet with a 12V psu it has 20dB gain and needs 662mV to reach its rated 15W into 4R at 10% distortion.

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