In WS442 power amplifier manufacturer predict place for additional circuit of delayed speakers switching on. Probably because of economical reasons or lack of posibility to purchase them, in almost all units, this place remains empty and only necessary connections are made. Today, all components are easily available, so that would be a sin, to not mount them having this device opened on the table. In this article I'm putting only schematic with a list of all missing parts.
The hardest component to get is a relay that would fit into PCB. I used S8M-24VDC-4CS SHORI ELECTRIC model. This 4-way relay. This fact increase its reliability due to higher number on contact points, which often decay and introduce sound problems/distortions.
