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Topping PA5 Review (Amplifier)

amirm

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This is a review and detailed measurements of the Topping PA5 stereo desktop amplifier. It was sent to me by the company and costs US $349.

PA5 enclosure looks like their standard DACs and such:

Topping PA5 Review Stereo Amplifier.jpg


Hard to imagine that an amplifier can fit in the same size but here we are. There are large slots for cooling on the bottom and sides which worked well to keep the unit cool during testing.

Back panel shows dual inputs which is nice:

Topping PA5 Review Desktop Stereo Amplifier.jpg


The beefy power supply reminds me what used to come with large gaming laptops. It is rated at 38 volts and 4 amps. In use, its temperature did not even rise above room temperature so I imagine it has good bit of headroom. Connection is a secure, screw on, two pin din style which I much prefer to flimsy barrel connectors used in many desktop amps.

Back to inputs, they are TRS balanced input which is fine by me. If you don't have such balanced cables, you can either use an adapter or get an XLR to TRS cable which is what I use. The compact form factor of these allowed it to have two such inputs instead of just one.

Speaker binding posts are the usual small ones on desktops but here they are spread apart thankfully which gets rid of 90% of the aggravation of inserting my large, locking banana plugs into them.

Note that there is no remote and volume control is the traditional one (not rotary). So if you need a remote, you should use a DAC with such and leave the amp with fixed volume.

Topping PA5 Measurements
As usual, we start with our dashboard:
Topping PA5 Measurements Stereo Amplifier.png


Wow, it has been a long time since I have seen such great SINAD score. Rounding it, it lands at 106 which puts it second in a list of over 160 amplifiers tested to date!

Best performance amplifier reviewed.png


Typical desktop budget amp struggles to get in the green. The better ones are in the upper half of the green. The PA5 is not only in blue but almost at the top of it. This is incredible achievement.

Yes, there is a bit of "cheating" going on in the form of low gain of 19 dB. Benchmark AHB2 which landed on top used the same. In practice, this is not a problem at all since max power was achieved at 2.5 volt which is well within the 4 volt range of balanced DACs.

And this is one extremely quiet amplifier:
Topping PA5 Measurements SNR Stereo Amplifier.png


My standard at 5 watts is 96 dB or 16 bits of dynamic range. PA5 sails past that to 18 bits or 107 dB. Just remarkable. Many amps can't even get to 96 dB. At full power, it clears 20 bits of dynamic range which means even then the noise it produces is below threshold of hearing.

Multitone test shows some distortion rise with frequency but still remarkably low:

Topping PA5 Measurements Multitone  Stereo Amplifier.png


I am always nervous running the frequency response test on class D amplifiers, worrying that their output filter interacts with the load and cause audibility issues. That was a worry for not:

Topping PA5 Measurements Frequency Response Stereo Amplifier.png


Yes, there is some variation but the design has made sure that happens a) in ultrasonics and b) with very low amplitude of change. We can see the reason for this in wideband FFT spectrum analysis:


Topping PA5 Measurements FFT spectrum Response Stereo Amplifier.png


Class D amps usually run at a frequency of 300 to 400 kHz. PA5 pushes this up to 600 kHz. This gives the output filter more room to roll off the response where its ringing is above audible band. Unrelated, we also see a super clean spectrum here. None of the usual messiness is here which we even see in high-end class D amps. Attenuation of the switching frequency is almost 40 db and not the usual 10 to 20 dB.

Crosstalk is extremely low:
Topping PA5 Measurements Crosstalk Stereo Amplifier.png


Considering how tiny this package is, I am so pleasantly surprised to see this level of performance.

Despite the tiny package, we have good bit of power into 4 ohm:

Topping PA5 Measurements Power into 4 ohm Stereo Amplifier.png


Allowing for 1% distortion, the available power naturally goes up even more:
Topping PA5 Measurements Max and Burst Power into 4 ohm Stereo Amplifier.png


Naturally switching to 8 ohm, cuts the power:

Topping PA5 Measurements Power into 8 ohm Stereo Amplifier.png


But notice how the PA5 matches and slightly outperforms the noise level of our current class D champ, the Purifi.

Sweeping the frequency vs power and distortion we get:

Topping PA5 Measurements Power vs frequency vs distortion Stereo Amplifier.png


We usually do not get curves that point down this much. This happens when distortion is so low that noise dominates. So very good showing there. Yes, there is rise in higher frequencies but we are starting at such a low baseline that this is exaggerated compared to other amplifiers.

Topping PA5 Speaker Listening Tests
I am confident of the transparency of this amplifier with respect to noise and distortion. However, I was curious how far its power goes. So I hooked up the PA5 to my Infinity Reference 253 speaker. I must stay, I was not prepared for the level of impact, fidelity and overall quality of the sound. The PA5 grabbed the ears of this speaker and pulled it any direction music asked it to like nobody's business! There was thundering bass. Superb high frequency and ability to fill my space despite only playing one speaker. It was hard to imagine this little amplifier powering this speaker so beautifully.

Conclusions
It is abundantly clear that ton of great engineering has gone into the design of Topping PA5. It breaks all barriers as far as noise and distortion, not only in its own budget/desktop class, but way, way outside of that. If it had double the power, it would obsolete all of them and in a hurry! As it is, I would certainly use it in a desktop or secondary system. And even primary if you are not going to blast the volume with super inefficient speakers.

It is my absolute pleasure to recommend the Topping PA5. The dynamics of stereo amplifier market just changed folks!

------------
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/
 
Last edited:

dwkdnvr

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Wow - this is close to the holy grail. Finally a great and inexpensive power amp to go with all the great DACs (and headphone/preamps) that we've seen.
Better pick one up before the ASR community drains the supply chain :)
 

JustAnandaDourEyedDude

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Thanks for another great review! A couple of the plots (multitone and power & distortion at 4 ohms) still refer to the A50 rather than the PA5.

Edit: Also, the SINAD comparison chart calls out the P50 instead of PA5.
This is a review and detailed measurements of the Topping PA5 stereo desktop amplifier. It was sent to me by the company and costs US $349.

PA5 enclosure looks like their standard DACs and such:

View attachment 168483

Hard to imagine that an amplifier can fit in the same size but here we are. There are large slots for cooling on the bottom and sides which worked well to keep the unit cool during testing.

Back panel shows dual inputs which is nice:

View attachment 168484

The beefy power supply reminds me what used to come with large gaming laptops. It is rated at 38 volts and 4 amps. In use, its temperature did not even rise above room temperature so I imagine it has good bit of headroom. Connection is a secure, screw on, two pin din style which I much prefer to flimsy barrel connectors used in many desktop amps.

Back to inputs, they are TRS balanced input which is fine by me. If you don't have such balanced cables, you can either use an adapter or get an XLR to TRS cable which is what I use. The compact form factor of these allowed it to have two such inputs instead of just one.

Speaker binding posts are the usual small ones on desktops but here they are spread apart thankfully which gets rid of 90% of the aggravation of inserting my large, locking banana plugs into them.

Note that there is no remote and volume control is the traditional one (not rotary). So if you need a remote, you should use a DAC with such and leave the amp with fixed volume.

Topping PA5 Measurements
As usual, we start with our dashboard:
View attachment 168485

Wow, it has been a long time since I have seen such great SINAD score. Rounding it, it lands at 106 which puts it second in a list of over 160 amplifiers tested to date!


View attachment 168486

Typical desktop budget amp struggles to get in the green. The better ones are in the upper half of the green. The PA5 is not only in blue but almost at the top of it. This is incredible achievement.

Yes, there is a bit of "cheating" going on in the form of low gain of 19 dB. Benchmark AHB2 which landed on top used the same. In practice, this is not a problem at all since max power was achieved at 2.5 volt which is well within the 4 volt range of balanced DACs.

And this is one extremely quiet amplifier:
View attachment 168487

My standard at 5 watts is 96 dB or 16 bits of dynamic range. PA5 sails past that to 18 bits or 107 dB. Just remarkable. Many amps can't even get to 96 dB. At full power, it clears 20 bits of dynamic range which means even then the noise it produces is below threshold of hearing.

Multitone test shows some distortion rise with frequency but still remarkably low:

View attachment 168489

I am always nervous running the frequency response test on class D amplifiers, worrying that their output filter interacts with the load and cause audibility issues. That was a worry for not:

View attachment 168491

Yes, there is some variation but the design has made sure that happens a) in ultrasonics and b) with very low amplitude of change. We can see the reason for this in wideband FFT spectrum analysis:


View attachment 168492

Class D amps usually run at a frequency of 300 to 400 kHz. PA5 pushes this up to 600 kHz. This gives the output filter more room to roll off the response where its ringing is above audible band. Unrelated, we also see a super clean spectrum here. None of the usual messiness is here which we even see in high-end class D amps. Attenuation of the switching frequency is almost 40 db and not the usual 10 to 20 dB.

Crosstalk is extremely low:
View attachment 168501

Considering how tiny this package is, I am so pleasantly surprised to see this level of performance.

Despite the tiny package, we have good bit of power into 4 ohm:

View attachment 168495

Allowing for 1% distortion, the available power naturally goes up even more:
View attachment 168497

Naturally switching to 8 ohm, cuts the power:

View attachment 168498

But notice how the PA5 matches and slightly outperforms the noise level of our current class D champ, the Purifi.

Sweeping the frequency vs power and distortion we get:

View attachment 168502

We usually do not get curves that point down this much. This happens when distortion is so low that noise dominates. So very good showing there. Yes, there is rise in higher frequencies but we are starting at such a low baseline that this is exaggerated compared to other amplifiers.

Topping PA5 Speaker Listening Tests
I am confident of the transparency of this amplifier with respect to noise and distortion. However, I was curious how far its power goes. So I hooked up the PA5 to my Infinity Reference 253 speaker. I must stay, I was not prepared for the level of impact, fidelity and overall quality of the sound. The PA5 grabbed the ears of this speaker and pulled it any direction music asked it to like nobody's business! There was thundering bass. Superb high frequency and ability to fill my space despite only playing one speaker. It was hard to imagine this little amplifier powering this speaker so beautifully.

Conclusions
It is abundantly clear that ton of great engineering has gone into the design of Topping PA5. It breaks all barriers as far as noise and distortion, not only in its own budget/desktop class, but way, way outside of that. If it had double the power, it would obsolete all of them and in a hurry! As it is, I would certainly use it in a desktop or secondary system. And even primary if you are not going to blast the volume with super inefficient speakers.

It is my absolute pleasure to recommend the Topping PA5. The dynamics of stereo amplifier market just changed folks!

------------
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/
 
Last edited:
OP
amirm

amirm

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Angsty

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It would also be nice to further amend the Infinity Reference 253 review given your findings with this amp. I'm very intrigued by it!
 

Rja4000

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Thanks for testing this one !

I was wondering: you test output impedance for headphones amps but not for speakers amps.
Is there a reason?
 

lewdish

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@amirm Theres a typo in the rankings image listing it as the P50 which is the linear power supply instead of the PA5
 

dougi

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Wonderful, but a bit surprised at the frequency dependent distortion rise. Even the B&O AS125 in the Yammie WXA-50 shows better behaviour. Still, at worst -60dBc so inaudible. Hell, the multi-tone looks like a DAC.
 

CedarWind108

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I need a glowing review from Amirm and Shawn from Zero Fidelity to make a blind purchase. Gives a good balance between the “measurements” side and “audiophile/how does it sound” side. Hoping Shawn reviews and likes it too as this is great value for a desktop setup. And looking forward to more powerful amps in the future.
 
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