Review on 🔊 Fosi Audio BT20A Bluetooth 5.0 Stereo Audio 2 Channel Amplifier Receiver Mini Hi-Fi Class D Integrated Amp 2.0 CH for Home Speakers 100W x 2 with Bass and Treble Control TPA3116 (Includes Power Supply) by Jay Hill

Overview: 【UPDATE】 2 Channel Mini Hi-Fi Class D Integrated Amplifier 2.0 Channel Stereo Audio Receiver for Home Speakers 100W x 2 with TPA3116 Bass and treble controls (with power supply) Purchased on 06/22/2018. I tried the amp with two purpose built studio speakers and played acoustic recordings of serious music with an output power of less than 20W RMS. According to Fosi, the total harmonic distortion was less than 0.5%, which allows for an appealing reproduction of stringed instruments. Intermodulation Distortion (IMD), which mixes the sound of multiple sources, was more noticeable, especially with human-voiced chord ensembles or choirs, and this is to be expected since a Class-D amplifier clips the audio signal. In fact, intermodulation distortion is present in most commercial loudspeakers whose internal surfaces are untreated, making it difficult to distinguish between the amount attributed to the amplifier and the amount produced by the speaker. In order to be able to assess the frequency response, the tone had to be adjusted. Knobs at 3 o'clock and were mostly flat and only dropped noticeably at very low frequencies, below 40 Hz. Organ music reproduction was perfectly acceptable even for 32-foot registers. A signal-to-noise ratio of around 70 dB is a value that we would like to recommend that the manufacturer work on. Bluetooth inputs are quiet and efficient. The usable range of Bluetooth is over 5 meters. Bluetooth 4.2 sound quality is sufficient for a second input. So 5 stars is more than 5 considering this is a class D amp.