The Story
In the Revox B126 CD-Player works the good old TDA1541A DAC, also known
as the R2R DAC (this is not a 1-Bit Sigma Delta DAC as you find
nowadays in all new CD-Players).

If you change the two Electrolitic-Condenser C104 + C204 (each 100µF) into a good
Foil-Condenser and you will get big improvement of the sound.

     See the changed Condensers and the TDA1541A DAC