Remember that ridiculous offset for one of the PZTs (14 volts)?

That was coming from the channel four of the AI output. The input  of the AI was not connected to DAC (dumb), but anyway in that state it was outputing 17 volts differential, and it looked as if it was not balanced:

CH4+ - CH4- = 17 volt

CH4+ - CH3- = 14 volt

CH4- - CH3- = 3 volt

CH3+ - CH3- = 0 volt

or some such.

I used a scsi cable and a breakout board to short out the AI input for this channel and it didn't change.

We need this offset for the alignment (until we relieve it), so at the moment it is left as is.