On 24/02/14 19:19, Milan Lazecky wrote:

Thank you Simon for positive reaction,
I start to look forward to prepare such synthesizer, will think about HDMI
audio, but at this moment I will be just happy with RPi stereo line-out.
Kind regards

You might not be so happy with the built in line out, it is a very basic output with very low quality audio. The hardware design is quite heavily focussed on playing media (preferably directly, on an otherwise headless system) through the HDMI output, and I've found the supplied libraries and code for doing this quite workable. The xbmc lot did a fair bit of work on this, and as a small device to attach to a projector they are great.

I've also used some small usb audio cards with good results, but did not need low latency or other usb stuff so I can't say how they'd go with your project.

Here is a link to one we used ...

http://www.ebay.co.uk/itm/UK-PCM2704-USB-to-S-PDIF-Sound-Card-DAC-3-5mm-analog-digital-output-volume-funct-/120940457164

but I think we got them a bit cheaper than that, and used a little amp about that size also ... for a bunch of sound sources. There are lots of little cards based on that chip, they probably all work well.


Simon