No sound from the preamplifier output

[dimusique]

Hi there!
i have a D120 with preamp out installed.I run the latest 8.1.3 firmware.I tried to connect the D to a pair of active speakers and use it as a preamp as i have no longer any passive speakers.Through the configurator i enabled the preamp output with variable volume and is enabled on all digital inputs too,but there is no sound at all.I tried multiple configurations 2 days now.On the information screen of the D the pre out seems to be installed and ON.The digital inputs seem to accept the signal from the sources but nothing from the pre out.
I am desperate!!Any ideas?Thanx in advance!