Update with photos

Have been playing with an initial test setup on 3 boards (DSP, DAC and PSU) screwed into a 2U rack case.​

The boards are the ADAU1452 board fitted with an ADAU1452 (I also have an ADAU1450 to test). The ADAU1966 DAC board. And the power supply board with only the 5V switching supply fitted. Just to note the 6V supply was added to drive things like the analogue supply on the DAC but as the current draw is so low the 9V output can be used instead.

The DAC board is currently wired to some phono sockets using only the positive output from the DAC (ignoring the negative terminal). This is through the passive filer only so there is DC present on the output.

I have not yet tested everything but the ADAU1452 DSP chip on the board I am using works. I do get 1 PANIC flag set in the core control under SigmaStudio after Downloading to the DSP (changes depending on settings). If you clear the panic flag this it does not come back. I need to test another board or two to see if this is a problem with my board/soldering method or something else. However so far the DSP does work and is happy to sit on my desk all day long doing so.

I do need a fast oscilloscope to check all the signals properly and adjust drive strength settings. Not sure I can borrow one at the moment so I might just have to invest in a reasonable Rigol mixed signal oscilloscope. The alternative would be a good analogue only oscilloscope and a USB logic analyser but it can be useful to have it all in one piece of kit.

The ADAU1966 DAC chip works and sounds pretty good directly driving a single ended headphone amplifier with only the passive filters. I have been running the sample rate at 96kHz to the DAC. This sample rate needs to use 2 I2S ports running in TDM8 on the ADAU1452. I do have an issue where the DSP will handle a full scale SPDIF signal, but if I do not reduce this by 12dB then the DAC distorts. I did not have this issue with the first program I downloaded to the DSP so I might have changed something by accident. 

I have been using the asynchronous sample rate converters on the ADAU1452 to feed SPDIF from my laptop to the DSP board. If you are not careful with sample rate settings in the DSP and to the DAC you can also make it sound average to horrible (think badly compressed MP3) so you have to be careful.

Just some close up pictures of the boards (click to view larger images):