When controlling the Peavey 5150II/6505+ with the CFX4 and this cable, the following applies;

CTL2 on/off	Channel
CTL3 on/off	Crunch
CTL4 on/off	FX Loop

CTL2 - CTL4 must perform LATCH type switching, not momentary, so;

If you're using MIDI Program Change messages to control the CFX4, follow the "Edit Control Configuration" section in the CFX4 user manual and configure the CTL functions listed above for LATCH type switching.

If you're using MIDI Control Change messages to control the CFX4, ensure your MIDI footcontroller is setup to transmit the MIDI Control Change messages for LATCH type switching as listed in the CFX4 user manual.

The Peavey 5150II/6505+ does not utilize the CTL1 function so it can be used with another amp/preamp.