I receive a lot of emails talking about connecting the Line 6 M13 using the “4 Cable Method”, or in the fast-paced, always-abbreviated forum world, the “4CM”. What they’re referring to is a way to connect your guitar effects processors up using 4 cables: 1) the guitar into the processor; 2) the processor into the front end of your amplifier; 3) a cable from the FX send of your effects processor into the amplifier’s effects loop; and 4) and cable from the effects processor’s FX return into the amplifier’s effects loop return. *Please note that I use “effects” and “FX” interchangeably. They are the same thing.
If you’re not sure what an effects loop is or why you’d want one, check out an earlier post here at TheToneChef.com where I teach you The Beginner’s Guide to Effects Loops.
So the M13 is a pretty great piece of gear because you get over 100 different stompbox style effects in one big, road-rugged container. It’s a big pedalboard all in one box. Don’t confuse it with the POD series though, because there is no amp modeling and no speaker cabinet (or microphone) modeling. The M13 requires that you plug it into an amplifier. It may sound pretty raggedy going straight into a PA, mixing desk, high end microphone preamp, audio recording interface, etc. Some may argue that the M13 effects aren’t as good or realistic as the effects they’re modeling and- while I fractionally agree- there is NO WAY ON EARTH that 1) you’d be able to buy 100+ stompboxes for $500- the cost of a new M13- or 2) that pretty girl in the front row is gonna hear the difference between a vintage out-of-production BOSS VB-2 and your M13 Vibrato patch. NO. WAY. ON. EARTH. And aside from the modeling vs. “the real thing” debate, the M13 makes it crazy simple to tap a button to sync just about ALL of your effects into tempo with one another. That is beyond brilliant. By tapping the tempo button along with your drummer, you can set 1 delay to a dotted 8th note, another delay to a whole note, a vibrato patch to triplet 16th pattern, and a filtered cosmic gurgle slurper to a half note. It’s like having a stomach ache that you can dance to!
ANYWAY. I digress. FX LOOPS and the 4CM. Here’s what the back of my M13 looks like:
I have marked mine with colored tape so that it’s easy to get everything plugged in, even if I have a tech or stage hand who’s helping me get set up.
You can see that there are stereo jacks for input, output, fx send, and fx return. However it’s not quite as easy as it looks. Instead of seeing it as putting your M13 in the loop of your amplifier, you have to think of it as putting your amplifier’s preamp section in the fx loop of the M13. Having said that, you’ll connect the M13 to your amp using the key in this diagram:
If you’re familiar with the M13, then you know that you can store multiple “scenes”. The location or placement of your fx loop can be assigned PER SCENE (from the setup menu) which means that in one scene, you can run one bank of effects into the front of your amp and the remaining three banks (each with three effects selections) into the loop. Or you can place the loop between banks 2 and 3 and have two banks into the preamp and two banks into the loop. It’s basically up to you where you want the preamp section of your amplifier to fit into the flow of the M13’s effects chain. The graphic below gives a visual of what that looks like:
You can also choose to have the loop before all the banks, after all the banks, or totally off.
So that is the long and the short of it. I’ve had my M13 since the first week it came out and it still never ceases to amaze me. In the last 2 months, I’ve built a dedicated board that uses the M13 as all of the swish, swirl, shock, and awe. You can see it below.