Finally had the time to test this - I can confirm that you can use a single pin on the Arduino to switch between SPDIF and I2S on the BIII-SE. If you want to see the code I used, I posted it here:
http://buffalodac.wordpr...udio-buffalo-iii-se-dac/

In the first instance I have decided to go with Version 5 & will move on to V5a once it is up & working.

V5 uses relays for the Source switching & the SPDIF/DSD switching. The Arduino & BIISE are isolated except for the I2C connection, V5a will have an isolator on the I2C. The Amanero will not be isloated in this version but will be in the V5a version.

Have made a start on the wiring but things will progress slowly due to time constants, my fancy soldering iron stopped working last night so this morning I dragged out my old iron which came directly from China, what a difference, can't wait for the new one to be fixed. Fortunately it is still under warranty It's a bit disappointing that the new Weller which cost 3 x the Chinese one stop after 11 months of light work & the Chinese clunker is still going.

Of course the code is written for V5a, so I'll have to make some minor changes for V5

As I'm doing a direct connection between the BIII SE & the Amanero, should I connect the Grounds as shown in the pic?

I remember reading in a post somewhere, that somebody had implemented a system where the audio system would turn off if a signal was not received after a period of time.

Does anyone know who posted that or how it would be done?

Edited by user Wednesday, February 20, 2013 9:40:41 AM(UTC)  | Reason: Not specified

Thanks

I'm actually looking for something I can put in the Sub I'm building for the son, it'll never get turned off otherwise :)

I tried to post a question on your site but I don't think it worked.

I assume I will need a 12vDC supply permanently powered to run the device?

How much current will the PSU need to supply to run the device?

Getting there slowly, I have made all of the custom bits & pieces, but it may not be until next weekend before I get to put the rest of the bits on the board. I'm also building a bedside table & starting a Sub for the son's birthday which isn't far away, too many things to do so little time

How are you dealing with common-mode distortion?

I'm seriously over soldering, not much to do now, connect the larger transformer, one more SPDIF input and the Mute & Lock LED, then test everything before I fire it up.

Is there any issue with me using a RED LED for the Mute, I remember reading somewhere that the different colour LED's used different amounts of current.

Is the Mute just to show when you don't have LOCK or is there a way to actually mute the DAC mid music?

Edited by user Sunday, March 3, 2013 7:35:19 AM(UTC)  | Reason: Not specified

I used red LED's at first, but now my build has no LED's at all. The display is also indicating if the DAC is locked to the signal. Only dropouts that happent for a split second are not likely to be picked up by the arduino.

The mute LED lights up when you mute your DAC using the arduino and also between the songs when automute is enabled. It has nothing to do with the lock state, but when automute is enabled it will stay muted while there is no lock :)