This is a review and detailed measurements of the SounDigital SD300.2D stereo car amplifier. It is on kind loan from a member. Apparently only 200 of these were built using GaN transistor technology. Not sure of the original cost ($1,300?).
From outside, the SD300 looks plain and and budget like:
This is no frills amplifier with large terminals for power, speakers and that is all she wrote. Did not get a manual so don't know what the power, X and triangle do. All web page references to it are gone.
SounDigital SD300.2D Measurements
I powered the unit using my Lithium custom power bank (rated for 100 amps continuous, 300 amps peak). Test voltage was nominally 13.4 volts and drop to 12.9 at peak power. Here is our dashboard:
Wow, this is stunningly good for a car amplifier. Actually, it would beat some 90% of the home amplifiers I have tested! Distortion is less than half of company spec.
Signal to noise ratio likewise, ranks up there especially in the good channel:
Frequency response shows that the amplifier filter does cause load dependency but it is at high enough frequency that should not be audible:
Crosstalk is good:
The amplifier took no time to reach stable operation:
Multitone test showed weakness at very low frequencies and high (latter being typical):
Fortunately the threshold of hearing is quite high in low frequencies so I don't expect an audible problem there.
Testing for power we get:
Allowing for more distortion and peak we get a bit more:
And 8 ohm:
So not a barn burner you would want to use for a sub and such.
I removed my AES filter and measured the full output spectrum:
Typical class D amplifier operates at around 300 kHz. Courtesy of GaN transistors, this has been upped substantially to 800 kHz. This is why the filter ringing was pushed up correspondingly in frequency response test. Very nice.
Edit: forgot to post the stepped frequency test:
Conclusions
When I test car audio gear, I automatically lower my expectations. Imagine my surprise when I saw the dashboard and how the SD300.2D outperforms majority of home amplifiers let alone car audio. Some smart designer in Brazil really took advantage of GaN technology to produce very low distortion and high performance amplifier. Alas, if it cost $1,300 for so "little" power, I can see how it would not sell as a mainstream product. Hope we see some variation of this come back to market and at higher power levels.
Oh, I forgot to note that the amplifier just got a bit warm during testing. So it is very efficient to boot.
It is my pleasure to recommend the SounDigital SD300.2D. A feather in the cap of our Brazilian members and visitors!
------------
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/
From outside, the SD300 looks plain and and budget like:
This is no frills amplifier with large terminals for power, speakers and that is all she wrote. Did not get a manual so don't know what the power, X and triangle do. All web page references to it are gone.
SounDigital SD300.2D Measurements
I powered the unit using my Lithium custom power bank (rated for 100 amps continuous, 300 amps peak). Test voltage was nominally 13.4 volts and drop to 12.9 at peak power. Here is our dashboard:
Wow, this is stunningly good for a car amplifier. Actually, it would beat some 90% of the home amplifiers I have tested! Distortion is less than half of company spec.
Signal to noise ratio likewise, ranks up there especially in the good channel:
Frequency response shows that the amplifier filter does cause load dependency but it is at high enough frequency that should not be audible:
Crosstalk is good:
The amplifier took no time to reach stable operation:
Multitone test showed weakness at very low frequencies and high (latter being typical):
Fortunately the threshold of hearing is quite high in low frequencies so I don't expect an audible problem there.
Testing for power we get:
Allowing for more distortion and peak we get a bit more:
And 8 ohm:
So not a barn burner you would want to use for a sub and such.
I removed my AES filter and measured the full output spectrum:
Typical class D amplifier operates at around 300 kHz. Courtesy of GaN transistors, this has been upped substantially to 800 kHz. This is why the filter ringing was pushed up correspondingly in frequency response test. Very nice.
Edit: forgot to post the stepped frequency test:
Conclusions
When I test car audio gear, I automatically lower my expectations. Imagine my surprise when I saw the dashboard and how the SD300.2D outperforms majority of home amplifiers let alone car audio. Some smart designer in Brazil really took advantage of GaN technology to produce very low distortion and high performance amplifier. Alas, if it cost $1,300 for so "little" power, I can see how it would not sell as a mainstream product. Hope we see some variation of this come back to market and at higher power levels.
Oh, I forgot to note that the amplifier just got a bit warm during testing. So it is very efficient to boot.
It is my pleasure to recommend the SounDigital SD300.2D. A feather in the cap of our Brazilian members and visitors!
------------
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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