The first test setup of the new Class-D amplifier project works. We have a fully digital connection between the Raspberry Pi and the amplifier. With the right driver (we have to work on this first), volume and also sound processing can be controlled directly from the Raspberry Pi.
Note: Don’t try to connect the output of an Class-D amplifier to an oscilloscope unless you know exactly what you’re doing. Many Class-D amplifiers use H-bridge outputs. In this case none of the output connectors is directly connected to ground. Connecting one of these pins to the ground of an oscilloscope can create a short-circuit and destroy your circuit and in worst case even your oscilloscope!
Here is another nice case that a HiFiBerry DAC user built:
Have a look at the nice details, e.g. the doors hiding the HDMI connector. There are more pictures here: https://www.dropbox.com/sh/xfqtr2hpkhmwfz0/ioV-QRo35g#/
Please do not steal Lego bricks from your children!
Have a look at this nice setup of a Swiss HiFiBerry DAC user. He used an old amplifier and added a Raspberry Pi, the HiFiBerry DAC and a wireless stick to create a very cool streaming audio player.
While we’re still looking for a partner that can provide a case for the HiFiberry DAC, here are some more ideas how to modify existing cases:
Norbert send me this picture:
On Twitter one HiFiBerry DAC user posted this:
A HiFiBerry DAC owner built this amplifier with an integrated Raspberry Pi. It has 2 line inputs and the Raspberry Pi + HiFiBerry DAC as sources. Amplification is done by a Class-D amplifier.
One of the HiFiBerry DAC users shows a nice example how to integrate the DAC into a standard case. He removed the onboard video connector and use the space for a phone connector. Really nice work!
HiFiBerry DAC installed in a standard case.
A HiFiBerry user asked, if it would be possible to use BruteFIR for room equalization with the DAC. I was pretty sure that BruteFIR only runs on Intel CPUs. Looks like I was wrong. It seems, that BruteFIR also runs on the Raspberry Pi. Alternatively JConvolver also implements FIR filtering on the Raspberry. One commenter noted, that he has a setup running BruteFIR with 32k taps and 50% CPU load on the Raspberry. Wow! This is something we have to look into. Using the HiFiBerry Digi with an additional SPDIF input would allow to use the Raspberry Pi as a flexible room-equalization module.
Has anybody implemented a setup like this already? Let us know!