Master volumes cannot turn up dB volume

Hi People Just bought a secondhand MC6000MKII having a few issues and would like to know if this is correct or not My setup is a Denon MC6000MKII into an iMac operating system big suf software Virtual DJ

When I went broadcasting I am suffering lack of signal strength(volume control) it seems that my master volume control on the top right-hand corner does not work on the Denon also on the channel gain’s I cannot turn them up any more as this will distort the music as well but on the Virtual DJ software it is set to maximum and I cannot seem to turn it up any more I would like more output power as the the music is going through but quiet and also should I turn the mic up it starts to distort if

This is a technical issue or is there something wrong with the Denon MC6000MKII

someone has got some time and has the same system and knows what they are doing to offer a bit of time to someone I am willing to give you my email address to pass on a telephone number to make things easier would much appreciate any assistance Thank You Mark

in case anyone is following this post I have just sent my Denon in for service with them and apparently the soundcard has gone £130 later should be fixed picking it up tomorrow secondly I can only recommend Denon services in Lysons Av Hampshire GU21 5QE Chris on technical support has been absolutely fantastic and brilliant with his help would recommend