This is a review and detailed measurements of the SMSL A300 stereo class D amplifier. It is on kind loan from a member and costs US $196.
The A300 is slick looking with flush volume control and switches. Alas, I am not a fan of the blue LED display from aesthetic point of view. It is nice and large though.
I really like the heavy duty binding posts. And for those of you needing subwoofer support, the filtered sub out and mains. It also includes Bluetooth functionality in addition to reading from a USB stick. With two inputs and a remote control, you are set for the modern audio systems of today.
If you are new to these measurements, please watch my video on understanding amplifier measurements.
SMSL A300 Amplifier Measurements
As usual we start with our dashboard:
Sum of noise and distortion as expressed in SINAD lands the A300 in the competent but average category:
Noise floor could be better:
We have our usual load dependency which exists in budget class D amplifier implementations:
So depending on what speaker you throw at it, the treble may be a bit bright or subdued. There are some tone controls you may be able to use to compensate.
Crosstalk was surprisingly poor:
I would have liked less high frequency intermodulation distortion:
We have decent amount of power into 4 ohm:
And naturally a lot less power at 8 ohm (thankfully most speakers are 4 ohm in bass where power is needed the most):
Our power sweep against frequency shows the dramatic rise in distortion at higher frequencies:
There is likely some audible pop in both power on and off:
Finally, the amplifier is stable at power on:
SMSL A300 BTL Amplifier Measurements
Edit, as requested, here are the BTL (bridged) measurements, starting with the dashboard:
We take a small hit in both noise and distortion. Let's see how much power we get in exchange:
The amp never clipped and just shut down so hard to determine max power. So let's measure it at 1%:
Wow, that is nearly 4X as the theory would predict assuming ample power supply current availability. Even 8 ohm benefits that way:
There is an important down side: the amplifier output impedance further doubles causing even more response error at 4 ohm:
Sub Out/Filtered Mains Output Measurements
Edit 2: here are the measurements of the sub output and mains set to filtered:
Conclusions
A year ago the A300 would have gotten a "good" performance mark. But we have seen a lot of high performance amplifiers at even lower prices that the absolute performance of the A300 drops to "not bad." Granted, the A300 has much more functionality with inclusion of remote, bass management, etc. So you get to decide what is important to you. Personally I like to see SMSL do much better on amplification front. It is hard as they don't have access to superb platform like they do with DAC chips.
EDIT: the A300 becomes a powerhouse in BTL mode, producing whopping 404 watts into 4 ohm! Alas, the load dependency increases even more potentially rolling off a lot of the high frequencies. Better use equalization to compensate with room measurement.
I am on the fence as far as recommending the SMSL A300.
-----------
As always, questions, comments, recommendations, etc. are welcome.
If you have audio equipment you like to have tested, please see this post: https://www.audiosciencereview.com/forum/index.php?threads/we-measure-audio-equipment-for-free.1995/
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The A300 is slick looking with flush volume control and switches. Alas, I am not a fan of the blue LED display from aesthetic point of view. It is nice and large though.
I really like the heavy duty binding posts. And for those of you needing subwoofer support, the filtered sub out and mains. It also includes Bluetooth functionality in addition to reading from a USB stick. With two inputs and a remote control, you are set for the modern audio systems of today.
If you are new to these measurements, please watch my video on understanding amplifier measurements.
SMSL A300 Amplifier Measurements
As usual we start with our dashboard:
Sum of noise and distortion as expressed in SINAD lands the A300 in the competent but average category:
Noise floor could be better:
We have our usual load dependency which exists in budget class D amplifier implementations:
So depending on what speaker you throw at it, the treble may be a bit bright or subdued. There are some tone controls you may be able to use to compensate.
Crosstalk was surprisingly poor:
I would have liked less high frequency intermodulation distortion:
We have decent amount of power into 4 ohm:
And naturally a lot less power at 8 ohm (thankfully most speakers are 4 ohm in bass where power is needed the most):
Our power sweep against frequency shows the dramatic rise in distortion at higher frequencies:
There is likely some audible pop in both power on and off:
Finally, the amplifier is stable at power on:
SMSL A300 BTL Amplifier Measurements
Edit, as requested, here are the BTL (bridged) measurements, starting with the dashboard:
We take a small hit in both noise and distortion. Let's see how much power we get in exchange:
The amp never clipped and just shut down so hard to determine max power. So let's measure it at 1%:
Wow, that is nearly 4X as the theory would predict assuming ample power supply current availability. Even 8 ohm benefits that way:
There is an important down side: the amplifier output impedance further doubles causing even more response error at 4 ohm:
Sub Out/Filtered Mains Output Measurements
Edit 2: here are the measurements of the sub output and mains set to filtered:
Conclusions
A year ago the A300 would have gotten a "good" performance mark. But we have seen a lot of high performance amplifiers at even lower prices that the absolute performance of the A300 drops to "not bad." Granted, the A300 has much more functionality with inclusion of remote, bass management, etc. So you get to decide what is important to you. Personally I like to see SMSL do much better on amplification front. It is hard as they don't have access to superb platform like they do with DAC chips.
EDIT: the A300 becomes a powerhouse in BTL mode, producing whopping 404 watts into 4 ohm! Alas, the load dependency increases even more potentially rolling off a lot of the high frequencies. Better use equalization to compensate with room measurement.
I am on the fence as far as recommending the SMSL A300.
-----------
As always, questions, comments, recommendations, etc. are welcome.
If you have audio equipment you like to have tested, please see this post: https://www.audiosciencereview.com/forum/index.php?threads/we-measure-audio-equipment-for-free.1995/
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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