My mother was cleaning out and came across this LA7B Loudspeaker, amplifier made by Marsland Engineering that my dad had from his PBX days.

It has a plug for 110 vac power supply and another cord for the connections with one heavy green wire (ground?), 2 black and 2 silver leads. This was used in 1A2 applications.

I don't find a wiring chart in dad's PBX manual.

Anyone know how to hook this up?


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