Updated: 14-Dez-04

The DDDAC1543 Support Site
Trying to be of some on-line help......

Most heard problem with first time installation... 
The DC Bias adjustment

I think, that two third of the problems which reach me have to do with this. The "complaint" is mostly that the DAC produces clearly audible distorted sound when music plays....

After checking the BIAS adjustments, normally every thing is ok. So if you fire up the DAC the first time make sure to do the following:

1. Adjust the Supply Voltage of the DAC to 8.0 to 8.5 Volt with P2. Measure the voltage on the chip (careful !) at PIN 5 of the TDA1543....
   (this is not so critical and it might safe  you some heat dissipation in the tower. If 8.5 works fine, keep it...
2. Now adjust with P1 the voltage directly measured at PIN 8 of the TDA1543 to 3.85 Volt. Now check PIN 6. This will not be exactly the same. Adjust P1 now again so, that you the average value between the two outputs is again 3.85V.... For example 3.95 and 3.75 ......
3. If the DAC plays music correctly, than repeat the procedure after a warm up period of minimum 10 minutes

Now the DAC is optimally Biased....

Happy Listening and Building !!!!

Doede Douma

IMPORTANT: The information provided on this page is intended as guide for DIY activities and therefore free to copy and or publish. If any one wishes to use any of the information from my WEB site, please make sure to refer and footnote to my URL Link as source! Doede Douma