NOISE SUPPRESSION PEDALS
The Four Cable Method:
The four cable method (4CM) utilizes four cables so a noise suppression/gate pedal can also quiet the preamp of the amplifier via the effects loop. The pedal is first allowed to get a baseline from the original guitar signal, the signal is sent back out of the noise gate to any noisy effects (distortion/overdrive), then continues to the amp's input jack where the preamp does its thing (the preamp is where the amp's great distortion happens), then back out through the effects loop send jack and into the noise suppressor again where the gate acts on it, then into the amp's effects loop return jack where it gets amplified by the power amp, and finally to the speaker.
Boss refers to their 4CM as the "X-method" simply because the NS-2 jack arrangement appears to criss-cross the signal within the pedal. Remembering this helps alleviate a bit of confusion when running cables, whereas the ISP G-string jacks are labelled to make it simpler to relate to. Think of the Boss NS-2's "Output" jack as the final output before the power amp then speakers.
4CM refers to the four paths between the guitar, the noise gate pedal, the amplifier input, and the amplifier effects loop. If you are running additional pedals, you will be adding patch cables. However, it is still referred to as the 4CM.
My General Thoughts on Pedal Arrangement:
- Let the noise gate detect the original/base signal by placing it right after the guitar (though I actually place mine right after my tuner).
- Place boosts (overdrive/distortion) after the noise gate pedal, just before the amp input. You generally want these pedals before the input on tube amps because they push the preamp tubes, where the good distortion is most often found.
- The amp's effects loop output sends the signal from the preamp to the noise gate. This path is my preferred location if using a single EQ pedal. However, I've personally not noticed a difference placing it immediately before, or after, the gate.
- The amp receives the gated/quieted signal from the pedal's final jack at the effects loop return. This is the section of the chain where I like to add modulation effects (chrous, reverb, and delay). Though these will not be quieted, this reduces "muddiness" because these effects are coming after all distortion influences. Some might prefer a "thicker" sound by placing these effects earlier in the chain, though.
- If running a passive preamp saturator (JHS Little Black Amp Box), this may be best placed right after the noise suppression pedal, just before the modulation pedals.
Notes on Effects Loop Labelling:
Preamp Out =
Effects Loop Send
Power Amp In = Effects Loop Return
Each of the four main paths/cables in the 4CM is represented by a different color.