Fosi Audio BL20A 200W Bluetooth 5.0 Home Audio Stereo Amplifier Hi-Fi Mini Class D Integrated Amp with U-Disk/3.5MM AUX/RCA Input and Remote Control for Home Passive Theater Speaker with Power Supply

Excellent amp! We hooked it up to a mixer that brings audio from a variety of sources, including Alexa, phono record player, music instruments (drums, guitar, keyboard, mic), our home theater and miriads of personal devices via Bluetooth.I am genuinely surprised at the quality of this amp! Regardless of the sources it does very good job and helps my good 125w speakers sound really great. Because my speakers' impedance is 8 Om the amp power output is somewhere around 50W, as I understand, not full capacity, but this is plenty for my living room.I liked it so much, I even bought a second amp by FOSI, a different model, for my children.There are couple of things I would consider before you buy this model:1) do you intend to use it with a separate subwoofer? If not, you might want to find a different FOSI amp that doesn't have subwoofer outlet and 2 extra controls (that means less knob controls to mess with).2) If you plan to switch between devices via Bluetooth often, say you have many family members who are going to hook their phones up to showcase something like the newest single of Tones and I - Dance Monkey, then you might want to look for another model, because this amp doesn't have a dedicated switch for the Bluetooth and you will have to interrogate everyone in your house, trying to figure out what device was last connected to the amp. If you don't find that last device and disconnect from it, you won't be able to connect yours. There is no way to turn off Bluetooth on this amp without switching the power off, but that won't help, because your last connected device will automatically connect and you are back in the interrogation room.3) Volume control knob. It is very small and too close to other controls. Not a problem for me, because I can control through mixer. Those of you not blessed with very delicate fingers - you will struggle with the volume control.4) I am not sure if this is my problem or the amp or Google's, but I could not figure out how to connect Google Mini to the amp via Bluetooth. It seems like Google Mini does not want to add amp as a Bluetooth device even though it sees the connection. Just FYI.5) no DAC technology. I don't know if this is very important for you. I guess if you are going to listen to inadequate quality mp3 files, you might need digital to analog conversion to improve sound quality, but who does it these days anyway, use streaming music in high quality compression and delete those old files.Otherwise, it is a great little amp that I never turn off, so I can communicate with artaficial intelgence (Alexa) and let the music fill the room on voice request.

You can't beat it for value or performance. I replaced a failing Cambridge Soundworks amplifier with this. Importantly; THIS kit comes with a power adapter (24v, 4.5a) of sufficient voltage and current to get max power out of the amp. 12-19 volts will not do it. Performance is significantly beyond what the Cambridge could do as to power, control, bass extension, and ability to play at max volume without sounding strained.This system was designed to run off a small 10wpc amp with 20 for the subwoofer. So, the satellites are ok but it'll absolutely overdrive the sub and bottom it out without judicious control of the sub volume. Which you can do! Because not only can you control the sub volume you can control the low pass frequency for the sub! Supposedly there's a switch inside the amp to allow the satellites to run full range but I don't see a reason to do so. High pass does not seem to vary along with the sub low pass.Sound quality is way beyond what I expected. It is not in the same class as a cheap LePai class T. It's very clean and musical. Extremely engaging to listen to especially on such a small portable system. No small Bluetooth speaker can match the impact of a real woofer and the amp drives it well.It's not going to push a monster 10" or 12" car sub. You need a sub/woofer that is fairly high efficiency as opposed to high power handling and max SPL. This is why the Cambridge system is perfect.At max volume it's a bit grainy up top and you can hear the amp go into mild dynamic compression but it never distorts unless the bass tone control is turned up. Use the sub volume instead.Bluetooth works great. No PIN pairing just scan pick and go. Must disconnect Bluetooth to use the aux input unfortunately but it's easy enough to do. Sound is not diminished that I can tell when using Bluetooth. I just got it tonight so I will update later.

For extremely reasonable price, purchased FOSI BT30C to implement a stereo system for our patio. Found unit to have plenty of power to drive Polk Atrium 5 speakers with high quality audio. Bluetooth audio worked flawlessly with every source paired, including an Amazon Echo. Unit and power adapter easily installed inside a 5"H x 9" W x 11" D cubby built into an over-sized fireplace enclosure. 120V AC duplex box installed at back of cubby, to plug in power adapter, was wired to a switched light circuit already installed near cubby. Unfortunately, if that switch is turned off with amplifier left on, speakers pop terribly... meaning amp must be turned OFF before switching off 120V supply. So, now to use the unit, we have to switch 120V on, then reach in cubby to switch on FOSI unit... which is the volume control. And, then to quit using the system, we have to reach into the cubby to turn OFF the amp so speakers won't get popped. This has proven to be a real annoyance, as knobs are quite small and placed close together. Note to FOSI Engineering... Do NOT have a power switch part of volume knob... OR fix the pop to speakers when adapter is turned off. I purchased BT30C, because it includes a sub-woofer output, which we've found really isn't needed with Polk speakers. Sub-woofer feature adds two knobs: one to control low-frequency cutoff and one for sub-volume, These two additional knobs is likely what force implementing ON/OFF with volume knob. If you're planning to implement a stereo system that has only 2 speaker (no sub-woofer), I'd advise purchasing BT20, which has a real switch for power ON/OFF. Wish I'd bough that unit instead...