AMI K ( JAK-200 )

I have an American AMI K ( JAK-200 ), Electric Selector using a 2017 mono amp and 2156 pre- amp. I have a problem with an AC ticking noise heard thru the speakers. It occurs when a record is playing and a selection is made. The ticks follow the number and letter selection made by the pulse generator that are sent to the pulse converter. I've replaced all the caps in the pulse converter, cleaned all the contacts in the pulse converter and pulse generator, relaced the wiper contacts on the pulse generator. These steps did not correct the problem. I've even added new ground wires between the mech and the pulse generator and the amp.
Has anyone had this problem and a fix?