So just for my own research since I'm also looking for a new integrated amp, anything below $300, I'm digging a little into the SMSL A50 Pro.
And as I said I don't believe that low cost necessarily means low quality sound, so I don't really care which amp is more or less expensive.
I'm always more than a little curious when an amp designer chooses another chip besides the
TPA3255 that 95% to 99% of all class-d amps use, such as the
TPA3221 chip used in the
Fosi MC331 and the
MA12070P chip used in the
SMSL A50 Pro.
Both chips are a lot lower power than the TPA3255 but very well
could sound better used within their intended power output range, which is likely easy with speakers of say 93db/1watt or greater sensitivity.
The MA12070P and the A50 Pro in general is an interesting design. The internal circuit board looks very empty. It doesn't have the common NE5532 opamp chips and many other larg capitors, inductors, and a big heat sink for the amp chip, etc... that most class-d amps have.
Internally it looks much more like a DAC than a power amp. When you research the MA12070P you learn why:
The MA12070P is a fully integrated Class D amplifier IC that uses multi-level switching technology for high power efficiency and low distortion.
It eliminates the need for many external components such as discrete op-amps, DACs, or analog amplification stages.
This integration leads to a much simpler, cleaner, and more compact PCB layout with fewer components visible.
The small board size and minimal components reflect the efficiency and compactness of the MA12070P’s all-in-one design.
Electronic volume control, crossover, and EQ are implemented digitally within the chip or via associated microcontrollers, not requiring external analog op-amps.
The implications of this are... 1)less manufacturing cost and so you can sell a product cheaper, and 2) there are less chips, capacitors, resistors, etc in the signal path (which is normally a good thing). Or at least less external things in the path. There is more internal things, inside the MA12070P chip itself. So the resulting sound could be better or worse depending on how well the chip has been designed.
When I asked an AI agent about the sound of the MA12070P compared to the TPA3255 the quoted text below was the response.
(keep in mind this is really just pulling people's opinions on average from sites like DIYAudio and AudioScienceReview)...
The sound character comparison between the Infineon MA12070P and the Texas Instruments TPA3255, based on user impressions and measured performance, is nuanced:
- The MA12070P is praised for its very low noise floor and high efficiency, delivering clean, smooth, and detailed sound especially at lower to moderate power levels typical in portable or desktop use. It is considered less harsh or "bright" by some listeners, offering a smoother and more even frequency response and better stereo separation.
- The TPA3255, on the other hand, is a high-power Class D amplifier chip capable of very high output power with excellent dynamics. It has industry-leading low noise and distortion specs and can sound extremely clean and powerful, rivaling Class A amplifiers in some setups. However, it may sound slightly more clinical or less "smooth" compared to the MA12070P, particularly in cheaper implementations without meticulous analog front-end design.
- In summary, the MA12070P tends to provide a smoother, more laid-back sound character on average, while the TPA3255 excels in power handling, clarity, and dynamics but can sometimes sound less warm or smooth depending on implementation.
- Many audiophiles suggest the MA12070P is ideal for lower power, high-fidelity applications with positive subjective impressions on smoothness and stereo imaging, whereas the TPA3255 suits high-power, high-performance setups where sheer output and dynamic control are critical.
Therefore, there is a perceptible sound characteristic difference: the MA12070P is typically "smoother" sounding, less bright or harsh, especially in modest power applications, compared to the more powerful, neutral, and dynamic TPA3255.
And here below is a picture of the inside of the SMSL A50 Pro.
If you've seen the internals of many class-d amps and DACs you know how strange this looks for a loudspeaker power amplifier especially a 2.1 amp with powered sub-out. It looks unbelievably empty. And btw, the other side of the board has nothing on it except two small bars of aluminum that transfers heat from the two power chips to the case.
But I view this more as a
possible positive versus a probable negative,
because when it comes to audio equipment I believe
less is usually better than more.... less power, less stuff in the signal path, etc.
but... really to a large degree the question comes down to
how good sounding is the
MA12070P amp chip and it's internal DAC ... if... it puts out enough power for YOUR speakers?
