Another thing It is doing is when first switched on and with the headphones I manage to get it very simply calibrated and I get about 10 seconds of playing time before the audio cuts out almost sounds like a mini power down but the panel is still fully working and it then through the line/headphones just randomly starts giving off noise. The keyboard is scaling in tune etc..  I was thinking the ADC or the DAC or an associate chip could be at fault but I am not sure if that would explain the panel freezing when connected to DI/Amp etc..