All the parts can be bought at Conrad except the TDA1543 which I got from Reichelt.
1) What schematic did you use (I think J. Swenson pointend at the schematic on the 2702 spec sheet)?
I used the schematic from the data sheet on page 29 of the PCM2707. Here is the version in an easier to red form.
2) Where did you get your crystal resonator from? Are there big quality differences here?
I have no clue if there are any differences in resonators, I just bought mine at Conrad, but I will be using what Brent uses.
3) How long can the 2706 and the 1543 work with the small alkalines? Altough supposedly noisier I`ll be using rechargables.
The alkalines were only a test setup. I tapped in the 3.3 V from the coputers SMPS and that worked pretty good. With some filtering that might be the ideal solution because any computer has a 3.3V line.
4) are you paralleling the caps as suggested in the 2702 spec sheet
Yes, but as in spec sheet of 2707
5) I think you used the be453 adapter fron conrad.de, how difficult was soldering?
I was concerned about soldering, but it is very easy. Just solder all the pins on one side at ones not paying attention if the solder flows between the feet. Do all the four sides like that and then use small solder wick with some soldering flux on it and pull of the excess solder. Then use a small cutter nife and scratch between the pins to make shure no solder remained.
6) What res. are you using for I/V (make and value)?
As a future project:
There is some issue with the PCM2706/07
Since I did an update on my XP the computer dosn`t recognize the USB device anymore. It worked flawlessly up to that poin. I have build and tried several devices because I thought at first that I killed the chip some how, but I had no luck. So I assume that it is a compatibility problem with at least the German version of XP. It is stated on the data sheed that the PCM2707 has been changed in May this year to make it compatible to XP Global, before that time it was only for the English and Japanese XP versions. Either the update did not work for the German XP version, or the samples I got last month are still pre May 05 versions.
Can you give me your phone number?