SNR ..........................................................................................................103dB This is my second amp based on this chip. I had already reviewed a fully symmetrical dual Mono MA12070 that I had built a few months ago.

The A20a 2022 does not have the abnormal noise from the power supply unit or the abnormal noise of the speaker output that I reported on the Sabaj A20a. I'm running in bluetooth right now, just because I don't want to haul too much stuff down here tonight. Connecting was easy/normal w my Samsung phone. Unfortunately this phone doesn't do Aptx HD, so I can't test that. SBC ..............................................................................16bit/44.1 kHz_328kbps

S.M.S.L VMV

The output power of the A20a 2022 is 170W (4Ω) / 90W (8Ω). It has more than double the output power of AO200 / DA-9 / SA300 / PA3. High output is possible with a dual power supply with a power supply voltage of + -34V (total 68V) for the MA5332MS chip. If you feel power shortage with AO200 / DA-9 etc., A20a 2022 is the best choice.

USB transmission ....................................................................Asynchronization Overall, this is a phenomenal performance level for a modern PCM DAC for both RCA and XLR line-level outputs. aptX-HD ..........................................................................24bit/48 kHz_576kbps

A large number of audiophile-grade audio components are used to enhance the subjective sense of hearing; I listened to the amp with my favorite Audiophile Playlist for 1 hour yesterday, it is really impressive @ first listening. Seems promising in relation to its ration performance / price. Build quality is definitely a step up vs some smaller/cheaper Aiyimas I've been messing with lately. Well, at least fit and finish - I can't comment on the internals.

THD+N ...................................................................................................0.004% I have previously pointed this issue to several manufacturers in China, but they didn't have any knowledge of Taper A and Taper B and couldn't understand my point. Only Chinese manufacturers use Tapered B for volume pots for volume control in the world. Bluetooth specification...................................................................................5.0The problem is that they are using the wrong volume pot for volume control on their audio equipment. Since I'm basically "throwing the book" of measurements at this device, we can see that certain characteristics are the result of the ESS DAC chip itself. For example the "hump" (THD and IMD) between -45 to -25dBFS or so, and the sinusoidal pattern of odd harmonic distortions when examined in very close detail with 0.1dB steps using a low-noise notch filter. USB compatibility ..................................Windows 7 / 8 / 8.1 / 11(Needs Driver) Mac OSX、Linux(Driverless) An amplifier that uses two MA12070 chips, such as the AO200 / DA-9 / PA3, has twice the output of one amplifier. But that's only when you connect a 2Ω load. When a 4Ω / 8Ω load is connected, only the same output as one amplifier can be obtained. This is the point where it is easy to make a mistake in the circuit operation of PBTL.

Anyway, no noise, no hiss, no distortion BUT I have not even gone close to turning it up anywhere near max (apartment). I'm running it right now on my "test bench" (aka in the garage) before I move it inside. I'm connected to some Snell K/IIs I keep down here for just such an occasion.Similarly, there is no fluctuation in the DC offset voltage of the speaker output and pop noise that I reported in SMSL DA-9. I tried to open the case to take pictures of the module, the PCB etc .. but unfortunately it is complicated to dismantle ... The amp is made in an aluminum case, it feels sturdy and beefy. The front of the amp has a mirror front and the volume controller has a dual function (volume and selector). When you press a few seconds on it , it powers ON / OFF. The amps also comes with a remote control.