Parallel to the battery:

  1. 6 x Rubycon ZL, 2'200uF, 25V
  2. Wima MKS4, 1uF, 63V
  3. Wima FKP2, 10nF, 63V

 

Results:

The above listed capacitors I had around and they were placed as close as possible to the DAC board. I did not experiment on exchanging one of the caps for another or adding one more. Switching them in had a positiv effect in terms of relaxation and queitness. There is no negativ effect when adding them.

Maybe one could try the same solution as done above for C10 replacement or just use much more capacitance.