This is a popular method for connecting multi-effects devices to guitar amplifiers that have effects loops. The 4-cable method allows processors that typically go in front of an amp to go into the input of the amp, while allowing those effects that are optimally placed in the effects loop of the amplifier to be connected there.
- The first cable connects the guitar to the multi-effects unit.
- The second cable connects the send from the guitar amplifier’s effects loop to an auxiliary input (or return) on the multi-effects unit.
- The third cable connects an auxiliary output (or send) from the multi-effects to the guitar amplifier’s effects loop return.
- The fourth cable connects the main output of the multi-effects unit to the main input on the guitar amplifier.
Inside the multi-effects unit, time-based and modulation effects that are best placed in an effects loops (delay, reverb, chorus, rotating speaker) are routed out the send, while processors that sit in front of the amplifier, such as compressors, overdrives, and wah go straight through to the multi-effects unit to the amp’s input.