Bang&Olufsen is known among users of hi-fi equipment, for its products characterized by a futuristic and elegant design.
For some time, however, it has entered with authority in the world of hi-fi self-builders thanks to the ICEPOWER line of high-performance amplifiers, devices that, in their professional version, are mounted in amplified loudspeaker systems all over the world.
The DSP has optical S/PDIF input and output and serial outputs connected to a 24-bit, up to 216 kHz four-channel PCM4104 D/A converter. The four outputs of the D/A converter drive four separate amplifiers, made with three integrated TPA3128D2 from Texas Instruments. One of these is used for two amplifiers dedicated to the high frequencies, which are capable of delivering up to 30W on 8 ohms if the card is powered at 24 V. The other two ICS are used as the two amplifiers dedicated to the low frequencies. In this case the particular configuration in parallel allows to deliver up to 60 W per channel, on 8 ohms and with 24 V power supply.
The DSP Analog Devices ADAU1451, capable of 32-bit computations, has 48 32-bit, 192 kHz input-output channels, and the quad 24-bit PCM4104 D/A converter, is capable of a sample rate up to 216 kHz.
Jet all this amplifying and calculation power, alone is useless. So the board was created to be connected to a Raspberry-Pi, and uses this minicomputer either as a source of digital audio, via the bluetooth or audio stream connection, both for programming the DSP.
The Raspberry-Pi board is connected to Beocreate via the GPIO. Another adapter, brings DSP pins outside and will be used for future expansions.
The card integrates seamlessly with the Raspberry-Pi, allowing, for example, to create a panel for LAN, USB and S/PDIF i/o.
The outputs of the amplifiers are on plastic terminal blocks. On the left the ones for the 60W / 8 ohm channels, on the right for the 30W / 8 ohm channels.
The combination of Beocreate and Raspberry-Pi allows to have a four-channel system, already amplified and programmable, with digital processing, useful to “bring back their vintage products“, and much more. thanks to this board you can, for example, design a two-way multi-amplified system with digital crossover, using two amplifiers per channel, to be placed into your own self-built loudspeaker systems, or a three or four way system, using two boards, which can be easily connected in cascade. The internal DSP can be used not only as a digital electronic filter but also as an equalizer for response and for the environment correction. In short, this card brings the audio experimenter to a higher level, for a reasonable price.
Taking advantage of the sample under test, in the next days we will provide a detailed description of the software of the board, with particular emphasis on internal DSP programming we will describe a simple project of a two-way loudspeaker system.