Excited to see an affordable
Yamaha class AB stereo amp in Amir Sir's recommended list :
•Extended frequency response
•No load dependency
•Solid build
•Treble response is not symmetrical
•Audible noise and distortion
In the graph showing power supply noise,
SMSL A300 & Fosi Audio ZA3 are rated much higher in the 'green zone', while Yamaha is on the borderline.
Is Yamaha RS-202 an overall better option than a SMSL A300 or Fosi Audio ZA3 ?
They are quite different devices, for functionnalities and technical design as well.
I summarize what are in my opinion their respective PROS ans CONS, but it's hard to compare them and make a firm statement on which one is the best buy. It all depnds on your needs and risks taking by buying SMSL (or Fosi) on line or not.
So :
YAMAHA RS202
Pros :
Class AB, no load dependecy, very large FR in the treble (possible better treble range, but is it always audible ?)
More powerful (not so important, about only 1 or 1.5 dB more in real use)
AM/FM radio
Bluetooth
(and DB+ for model D, in Europe only it seems)
Bass/treble controls
Well long time respected and distributed brand, service easier, possibilities to buy and repair are easier
Cons :
No EQ,
No phono input (more sophisticated Yam receivers have one)
Less good headphone output (but depends on phones and SPL level you need -be careful for your ears)
Distorsion in bass and average SNR (probably not a major concern in real use with budget speakers, I guess nobody will use these 2 amps with large top range speakers)
SMSL A300
Pros :
Much smaller and lighter, neat modern design
Class D : draw less power
Less distorsion, very clean performance
EQ
Bluetooth
Better headphone output (but depends on phones and SPL level you need -be careful for your ears)
Subwoofer output
Cons :
No AM/FM nor DAB+
No phono input
Less power (not so important in real use- only 1dB less about)
Slightly load dependent (maybe less "natural" in treble depending on speakers)
Newer brand (with a growing good reputation) but buy on line only, less easy for service and repair
As for the FOSI, it's a good minimalistic little amp, but it lacks functionnalities, so I don't take it into account for a fair comparison.
The choice is yours, as always.