dsf to wav : what CPU power ?

[simoncn]

This is a problem with your control point. The control point should discover from each renderer what MIME types it supports and send the first compatible MIME type to the renderer. This works correctly in Linn Kinsky and in BubbleUPnP (if the relevant option is enabled).

In your specific case, the Oppo should inform the control point that it supports audio/x-dsf and audio/x-wav. The Linn should inform the control point that it supports audio/x-wav. With this information, the control point can do the right thing for both renderers.

I suggest you report this as a bug to the authors of your control point.