Review on 🔵 DROK Blue~Tooth Board: Portable, 5V-24V Audio Receiver for DIY Home Sound System with Micro USB Port by Edwin Kreps

Bought for 2 reasons:1. to avoid using other Bluetooth boards that require the use of a buck converter to reduce the voltage2. to eliminate the slight, high-pitched hum that comes with other Bluetooth boards I've used. Although this board operates over a wider range of input voltages, it cannot eliminate the high-pitched hum heard at very low volumes. I tried matching the gain on all the board's amplifiers I tested it on to make sure all grounds were connected and used a shielded cable to carry the audio signal. Unfortunately the noise is the same as if I used a downconverter and a cheaper Bluetooth card. Remember that it is powered by a battery and not a switching power supply and all connections are soldered and solid.