Hello,
Is it possible to buy tweaked version of a A20 board, with better low noise regulator for example ?
it is to build an audio drive ...
Thx
Yes, you can build your own modified version of the A20, but it's not a simple task unless you have some experiences with designing of advanced electronic and some way how to make the resulting PCB.
IMHO the easier way is to use an external soundcard, even the cheaper USB ones are probably still superior to the built-in soundcard inside the SoC. And if you dont want the USB, there are some high-quality sound chips, conected by buses like the I2C or SPI, for example the Wolfson Audio Card for Raspberry Pi (see, for example, http://uk.farnell.com/wolfson-microelectronics/wolfson-audio-card/audio-card-for-use-with-raspberry/dp/2347264 (http://uk.farnell.com/wolfson-microelectronics/wolfson-audio-card/audio-card-for-use-with-raspberry/dp/2347264)), which can be probably easily adapted to connect to UEXT/GPIOs connector.