This is a review and detailed measurements of the Topping PA3
s 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:
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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:
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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:
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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!
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