Hi was wondering
If the Xonar Phoebus can use a 6 pin pcie than using the included molex-6 pin
Just got one of those and to be honest not impressed at moment due to the fact that the control box that should control volume and mute doesnt work and the sound quality is to say the least poor. Could be that I need to fine tune the settings but at present getting a lot of echo on games and very tinny sound ,Im thinking of RMAing it for a D2x
and to answer ur question it does need a 6 pin power connector I have used one from my psu and not the molex adaptor supplied.
Did you connect the box link correctly? For me, the control box works quite well but you need to plug the box link on the rear panel more tightly. The echo issue might be the wrong use of ROG Command noise reduction or other environmental sound effects enabled without awareness. Try to reset it as suggestions above and if still not working well, you need to RMA it for sure!!