This is a review and detailed measurements of the Topping A50III balanced headphone amplifier. It was sent to me by the company and costs US$199.
The A50 III is solidly built and is about as thin as you want it to be. User interface is simple: short press of the power button cycles through three separate gain settings. Both 1/4 unblanaced and 4.4mm "balanced" (really differential) headphone jacks are provided. Volume control is purely analog. A very small external switching power supply is provided:
Nice to see universal inclusion of trigger automation in Topping products. The toggle switch is easy to find by feel so not an issue for it being on the back as the single control.
Balanced is provided through 1/4 jacks. You can either get an adapter from XLR or do as I have: use a cable that is 1/4 at one end of XLR at the other. They are quite common and cheap.
Topping A50 III Measurements
I started with balanced input and output:
While excellent with incredibly low distortion, results are still below the standard Topping has set. So I tested unbalanced input/output:
Distortion is now stunningly low at -145 dB! Overall noise has gone down even though we now have a tiny bit of mains noise. The new SINAD places the A50 III shoulder to shoulder with other state of the art headphone amplifiers:
Per company spec, you can achieve the above results with either balanced or unbalanced inputs. It is the balanced output which has slightly lower performance in exchange for a lot more power.
Noise performance with same unbalanced in and out is superb:
Indeed, at 50 mv output, it tops our charts:
If you have a super sensitive IEM, this is the headphone amp for you!
Frequency response is exceptionally wide and flat:
There is good bit of exceptionally clean power available using 1/4 unbalanced output:
Interestingly, the medium gain has better performance than low gain. Balanced output as mentioned, brings more power but at slightly penalty of objective performance:
Same story holds for 32 ohm load:
Protection circuit kicked in when using balanced output, shutting the unit down. In this mode, the amp doesn't want to clip which made my power sweep test vs impedance difficult. So I ran it with unbalanced output:
Distortion increases above 1 volt which you can remedy by using balanced output.
Channel balance is excellent:
Conclusions
Topping yet again meets the very high standard we expect from the company in A50 III: Budget prices with state of the art performance! There is a bit of trade off with balanced mode where you get more power but also a bit more noise. But if you need the power, the noise will not be material since the headphone is insensitive to it anyway.
It is my pleasure to recommend the Topping A50 III.
------------
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/
The A50 III is solidly built and is about as thin as you want it to be. User interface is simple: short press of the power button cycles through three separate gain settings. Both 1/4 unblanaced and 4.4mm "balanced" (really differential) headphone jacks are provided. Volume control is purely analog. A very small external switching power supply is provided:
Nice to see universal inclusion of trigger automation in Topping products. The toggle switch is easy to find by feel so not an issue for it being on the back as the single control.
Balanced is provided through 1/4 jacks. You can either get an adapter from XLR or do as I have: use a cable that is 1/4 at one end of XLR at the other. They are quite common and cheap.
Topping A50 III Measurements
I started with balanced input and output:
While excellent with incredibly low distortion, results are still below the standard Topping has set. So I tested unbalanced input/output:
Distortion is now stunningly low at -145 dB! Overall noise has gone down even though we now have a tiny bit of mains noise. The new SINAD places the A50 III shoulder to shoulder with other state of the art headphone amplifiers:
Per company spec, you can achieve the above results with either balanced or unbalanced inputs. It is the balanced output which has slightly lower performance in exchange for a lot more power.
Noise performance with same unbalanced in and out is superb:
Indeed, at 50 mv output, it tops our charts:
If you have a super sensitive IEM, this is the headphone amp for you!
Frequency response is exceptionally wide and flat:
There is good bit of exceptionally clean power available using 1/4 unbalanced output:
Interestingly, the medium gain has better performance than low gain. Balanced output as mentioned, brings more power but at slightly penalty of objective performance:
Same story holds for 32 ohm load:
Protection circuit kicked in when using balanced output, shutting the unit down. In this mode, the amp doesn't want to clip which made my power sweep test vs impedance difficult. So I ran it with unbalanced output:
Distortion increases above 1 volt which you can remedy by using balanced output.
Channel balance is excellent:
Conclusions
Topping yet again meets the very high standard we expect from the company in A50 III: Budget prices with state of the art performance! There is a bit of trade off with balanced mode where you get more power but also a bit more noise. But if you need the power, the noise will not be material since the headphone is insensitive to it anyway.
It is my pleasure to recommend the Topping A50 III.
------------
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/
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