I am very satisfied with the upgrade and the change in sound was so obvious I was really surprised. I can start naming all the changes in sound but it is really like listening to a much better cd-player.
However there was an issue installing the modules.The NAD 524 cd-player has some simple Op-Amps but the +12 V and -12 V power was fed trough a 220 ohm / 0,5 Watt resistor to the Op-Amps resulting in +/- 10 V dc.
The current needed by the Burson HD Opamp was much higher so the introduced voltage drop over these resistors changed from 2 Volt to approx. 10 Volt. The sound was very distorted and I did not know why …. Until I realised what happened measuring all voltages.
Oystein’s setup page: http://my.hifi.nl/index.php?user=16089