The unit works well with its own dc power. With the zoom one, only the LED is on when the effect is engaged. I can hear the “normal” sound but no delay at all while the other effects works normaly. Is there any “hi” voltage protection on this unit? I measured the voltage the dc power when nothing is pluged in: it’s about 12/13V… You only have 9V when the current is 300mA. This is a bad tension source….