Had a look at the pin outs on both the power amplifier and the power supply regulator boards and the maximum potential difference between any two adjacent pins is 190 volts. EG. +300 v to +190 v to 190v return to -190v to -300v on consecutive pins on the power amplifier board. A similar situation exist on the power supply regulator board, at no stage is there a 300 volt difference between any two adjacent pins, so this should drop the possible arcing problem considerably Ken Goodhew. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com