S.M.S.LSA300 HiFi Digital Amplifier, Infineon's MA12070 Chip Class D Power Amp, RCA USB Bluetooth 5.0 APTX Input, Multiple EQ Modes with Remote Control (Black)

For near-field listening with bookshelf speakers (Micca RB42 and others), this amplifier sounds every bit as good to me as my old Carver 500W per channel class A/B amplifier. It is dead silent when the audio program is silent, and has ample power to drive the RB42s as loud as I care to listen with absolutely no signs of stress. The sound is very clean and pure with no faults that I can detect through the speakers I've tried it with.The power consumption is very low. It draws less than 1.5 watts when idle. When listening at levels I consider comfortable, the power consumption only rises by a few tenths of a watt. To increase the consumption by even a watt or two, I have to crank the volume up to the point where it is louder than I generally enjoy. When the amplifier is switched off, its bundled power supply draws 0.6 watts. By comparison, my old class A/B amp draws about 25 watts when idle, and the power consumption rises by 10s of watts at normal listening levels, easily going into the 100s when moderately loud.Due to the low power consumption and high efficiency of the SA300, neither the amplifier nor the power supply get noticeably warmer than ambient even when listening for a long time at levels I consider "loud". The enclosure has no ventilation holes, thus there is virtually no risk of dust or other contaminants getting inside. It appears to be very solidly built, and there is no reason to expect thermal stress or dust to shorten its life.One fault I found with this amplifier is that its bundled power supply uses a grounded cord and connects the electrical service's equipment ground to the analog audio input's ground. When using the analog input, this results in ground loop induced noise if the audio source is also grounded (for instance, an older style computer that uses a grounded power supply). For many applications, this won't matter, but it does limit the range of analog audio sources you can use without noise issues.Another minor fault for some applications is that the display is always lit, and cannot be shut off. It isn't too bright, but it would be for a room where I am sleeping or for a home theater if positioned where it is in view.There are many features I like about this amplifier. The speaker terminals are robust and can be comfortably screwed down on 14 gauge wire, and they also accept banana plugs. Bluetooth and USB audio sound great (no detectable flaws), as does the analog audio input when used with non-grounded sources. The bundled infrared remote takes two AAA batteries that are not included, so you don't end up with extra disposable batteries that you may not want. The amplifier itself is small and not too heavy (1.5 lbs), and the bundled power supply is even smaller, so it's fairly easy to pack it up and take it places. Bluetooth range, though I haven't tested its limits, is ample for my needs (at least to the furthest walls of my room). The display is functional and unobtrusive (nothing moving or flashing) and even lets you select different colors, but cannot be shut off. Volume is controlled in discrete steps (60 max) via either the remote or the knob which has detents corresponding to the steps. Pressing in on the knob accesses a menu via which tone controls, a few preset EQ modes, and other features can be accessed.The Bluetooth and USB audio inputs work perfectly with all sources I've tried including Ubuntu Linux. On Ubuntu 20.04.2 LTS, I had to install a sound output control application (named "Sound") to send audio output to the USB device, but the OS recognized the device right away with no need for additional drivers. The Bluetooth audio output from Ubuntu worked fine even before installing "Sound". The audio quality from Bluetooth and USB are equivalent (no differences that I could detect) when playing audio from Ubuntu Linux.Overall, I am very pleased with this amplifier. One minor improvement I can think of would be a floating power supply (so that grounded analog audio sources aren't affected by ground loop noise). Another improvement would be to allow the display to be shut off (for use in home theaters or rooms where people are sleeping). For what I am using this amplifier for (near-field listening at my computer desk, and occasional temporary setups in other rooms or out in the yard), it is perfect just the way it is.

Purchased to setup a desktop / computer system. FWIW I am an "audiophile"; I have a main system with a high-end tube amp, planar speakers and a pretty good turntable.The SMSL SA3000 + speakers setup is less than 1/100 the cost of that system and yet it's super-listenable and functional. It sounds very good through bluetooth (streaming from Iphone) but is significantly better sounding (smoother, more detailed) when connected to my PC laptop via USB using the SMSL's built-in DAC. I was surprised that worked absolutely flawlessly, windows recognized it immediately. Haven't used the line input, so can't comment on that.For speakers, I built a small set using a kit from Madisound (Mark Audio Tozzi, $160 / pair), these are a great match, very clear, especially good on vocals, but fairly bass shy. I also considered some small Polks and a kit from Dayton audio as well as Q acoustics. In particular, the Q acoustics seemed like another great match (with excellent reviews) but they were in the $300 range and I was trying to come in under $300 total for a pair of speakers AND the amp. If you're curious, the Tozzi kit takes less than an hour to put together; there's a youtube video with good instructions.A couple of surprises:1) SMSL SA300 / Tozzi setup works very well with Zoom, voices are far, far clearer and easier to understand2) The built in equalizer is very useful, for these very small speakers I use the "bass" setting which fills them out a bit. From past experience with Polk speakers, my guess is they might be a better choice of you're willing to sacrifice a bit of clarity and imaging for fuller bass.3) I thought having a remote was a little silly since amp is right next to me, but having remote volume turns out to be very useful4) Power is good, system can play loud enough to fill a smallish room without distorting or sounding strained.5) Never gets warm, everCould I live with the SMSL SA300 in my main system?Honestly, if I added in a subwoofer and played music mostly by streaming high-res TIDAL or Qobuz I think it would be fine. IMHO a modern streaming system like this gets you about 75% of the way there for a fairly reasonable price. Audiophiles (like me?) can sometimes seem a bit snobbish, but in reality high-end audio is classic case of diminishing returns, the SMSL SA300 is excellent proof of that principle.My only regret at all, was that if I were going to do it again I'd probably get the red SMSL A300 - I think that plus the red Tozzi's would look really sharp.