Hi all,just a few points i need answers too,here goes,today i started building an us cleaner using 2x 100watt drivers and 4x 50watt transducers,im running them in pairs in parellel if that make sense,firstly i tested it with just 2 out of 4 transducers connected for about 30 seconds,it seemed ok,i unplugged it and went to connect the other driver pcb to the remaining 2 transducers,on toutching one of the unconnected transducer terminals i got a hefty shock,even tho at that point it hadnt been powered,is that normal?,at that point the tank wasnt grounded,i made a cock up connecting one of the last two transducers,i got the polarity crossed on one of them,it was only when i saw the last 2 i connected i discovered it!,i redid the connections and corrected my silly mistake,on powering up then there was a flash from the 2nd driver board,a heatsink was badly positioned and shorted on a adjoining pcb track,i sorted that but it had shorted 4x 1n4007 bridge diodes and a npn switching transistor also a 2.2ohm 5 watt resistor,as well as blowing fuses,i sorted that ,then tested it on my known working transducers and it worked,i then swaped it back to how it was wired originaly,turned on and the number 2 pcb that i just repaired and had working on no one bank of 2 transducers went bang,is there a way to test the transducers with a dmm etc,i would think there hard to kill?,the last blowup was the transformer windings shorting,that was on the previous good pcb,i am now trying to make a good one out of the pair until i can get replacements,but need to test the transducers are not blowing the driver board up,also i measured the voltage to the transducers at over 1kv when working,is that normal?,seems lethaly high.,any ideas?,cheers Paul m3vuv.