Boris Landoni from Open Electronics writes about the BF 15+15W open source power amp:
The amplifier revolves around a monolithic integrated circuit for universal use, that is composed of two BF amplifier stages having a bridge output, that may be equated to operational amplifiers connected by a bridge and supplied with a low impedance output stage; each stage has a fixed voltage gain that is internally set by the retroaction resistors (they are quite accurate and guarantee a maximum gain difference, between the right and the left channel, of just 0.5 dB) of these operational amplifiers, that is equal to 32 dB, corresponding to about 39 times the original signal.
