This is a review and detailed measurements of the Topping PA5 II stereo balanced amplifier. It was sent to me by the company and costs US $219 (sale). There is a plus version with higher current power supply for $289.50.
The fonts are hard to see but there is not much to read anyway. A power input button nicely lets you set trigger setup as well (so another device can power it on). The other switch lets you select between balanced and RCA which lets you use it as a pre-amp in a minimalistic system. I like the red ring around the volume control. There are large slots on each side for cooling (not shown). And regulatory certifications underneath (again, not shown). Back panel is what you expect:
I like that the binding posts are separated allowing for my larger banana plugs to go in there with much more ease than typical desktop amps. As you see, balanced uses 1/4 connectors which are readily available. The external power supply I have is rated for 3.2 amps which I believe qualifies this as the normal version with Plus coming with 4 amp one.
Note: I put my college repairing a ton of power amplifiers. So take my word for it that amplifiers have much higher failure rate than other audio gear. To that end, this is a new amplifier and may have issues. In my testing, I pushed the unit very hard many times into clipping and shut down. A power cycle got it back working again. Heat was spread across the whole case which shows attention to that front. Still, large scale production may show issues that did not occur to my samples. So if you are risk averse, you may want to wait a bit or buy from a supplier that accepts easy returns.
If you are not familiar with these tests, please watch this video on amplifier measurements.
Topping PA5 II Amplilfier Measurements
As usual we start with our dashboard:
We expect superb performance from Topping even whey they use chip based class D amplifier and we get it here:
Gain is fairly low but matches what we get out of desktop/modern DACs so not issues there. Using RCA input you actually get more gain:
From here on, I will only be using XLR input starting with our SNR:
My target for 5 watts is 96 dB or 16 bits and the PA5 II sails way past that. At full power, it reaches provably inaudible noise level even with very sensitive speakers.
A concern with lower cost chip based class D amplifiers is load dependency at higher frequencies. Topping has managed to make that essentially a non-issue:
Distortion is extremely low but rises some at higher frequencies:
Which causes some penalty for our 19+20 kHz test but still quite good:
Edit: forgot to include crosstalk:
Power sweeps show the excellent levels of noise and distortion:
Power is healthy for such a small package and lower tier power supply:
The amp does get non-linear at higher frequencies which in the context of its very low noise, let's us see how:
I was very pleased to see power on and off pop be well below my 1 millivolt threshold:
Finally, the amplifier is stable on power up so no need to leave it on:
Conclusions
I am not sure of the motivation for going from PA5 to PA5 II (reliability?) but whatever it is, we have another winner from performance point of view. The unit easily lands in our top 20 best amplifiers tested as far as combination of noise+distortion. I like the heat distribution and load independency. I would personally pay the other $70 and get the plus version but even here, you have good amount of power to drive a couple of bookshelf speakers.
I am happy to recommend the Topping PA5 II stereo amplifier.
Manufacturer SPECIFICATIONS:
Measured: 16.6cm x 12.9cm x 4.1cm
Weight: 680g
Power input PA5 II: DC38V/3.0A (2 pin aviation connector)
PA5 II PIus: DC38V/4.0A (2 pin aviation connector)
Signal inputs: SE(RCA L+R)，BAL(TRS L+ R)
Signal output: Speaker terminal (BTL)
Power on & off: by manual/trigger signal
Volume control: Analog Potentiometer
Display: White LED
Standby power consumption: <0.5W
----------
As always, questions, comments, recommendations, etc. are welcome. Click here if you have some audio gear you want me to test.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The fonts are hard to see but there is not much to read anyway. A power input button nicely lets you set trigger setup as well (so another device can power it on). The other switch lets you select between balanced and RCA which lets you use it as a pre-amp in a minimalistic system. I like the red ring around the volume control. There are large slots on each side for cooling (not shown). And regulatory certifications underneath (again, not shown). Back panel is what you expect:
I like that the binding posts are separated allowing for my larger banana plugs to go in there with much more ease than typical desktop amps. As you see, balanced uses 1/4 connectors which are readily available. The external power supply I have is rated for 3.2 amps which I believe qualifies this as the normal version with Plus coming with 4 amp one.
Note: I put my college repairing a ton of power amplifiers. So take my word for it that amplifiers have much higher failure rate than other audio gear. To that end, this is a new amplifier and may have issues. In my testing, I pushed the unit very hard many times into clipping and shut down. A power cycle got it back working again. Heat was spread across the whole case which shows attention to that front. Still, large scale production may show issues that did not occur to my samples. So if you are risk averse, you may want to wait a bit or buy from a supplier that accepts easy returns.
If you are not familiar with these tests, please watch this video on amplifier measurements.
Topping PA5 II Amplilfier Measurements
As usual we start with our dashboard:
We expect superb performance from Topping even whey they use chip based class D amplifier and we get it here:
Gain is fairly low but matches what we get out of desktop/modern DACs so not issues there. Using RCA input you actually get more gain:
From here on, I will only be using XLR input starting with our SNR:
My target for 5 watts is 96 dB or 16 bits and the PA5 II sails way past that. At full power, it reaches provably inaudible noise level even with very sensitive speakers.
A concern with lower cost chip based class D amplifiers is load dependency at higher frequencies. Topping has managed to make that essentially a non-issue:
Distortion is extremely low but rises some at higher frequencies:
Which causes some penalty for our 19+20 kHz test but still quite good:
Edit: forgot to include crosstalk:
Power sweeps show the excellent levels of noise and distortion:
Power is healthy for such a small package and lower tier power supply:
The amp does get non-linear at higher frequencies which in the context of its very low noise, let's us see how:
I was very pleased to see power on and off pop be well below my 1 millivolt threshold:
Finally, the amplifier is stable on power up so no need to leave it on:
Conclusions
I am not sure of the motivation for going from PA5 to PA5 II (reliability?) but whatever it is, we have another winner from performance point of view. The unit easily lands in our top 20 best amplifiers tested as far as combination of noise+distortion. I like the heat distribution and load independency. I would personally pay the other $70 and get the plus version but even here, you have good amount of power to drive a couple of bookshelf speakers.
I am happy to recommend the Topping PA5 II stereo amplifier.
Manufacturer SPECIFICATIONS:
Measured: 16.6cm x 12.9cm x 4.1cm
Weight: 680g
Power input PA5 II: DC38V/3.0A (2 pin aviation connector)
PA5 II PIus: DC38V/4.0A (2 pin aviation connector)
Signal inputs: SE(RCA L+R)，BAL(TRS L+ R)
Signal output: Speaker terminal (BTL)
Power on & off: by manual/trigger signal
Volume control: Analog Potentiometer
Display: White LED
Standby power consumption: <0.5W
----------
As always, questions, comments, recommendations, etc. are welcome. Click here if you have some audio gear you want me to test.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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