Here's a replay of my 2013 post with 2015 updates:
I added an Effects Loop to my old AX2!
by KaZoom1618 on 2013-01-13 14:37:44
So I have an Line6 AX2 that I luv, but I got a looper for Xmas, and it's the one effect that the AX2 is missing...
Now if I place the looper between the guitar and AX2, the guitar is recorded 'clean' so that any effects that I set are applied to all loops as well as the live soloing. Not nice.
I downloaded the schematics, and wow - this is the easiest modification to make! I didn't even have to cut any traces - Line6 ran a multiwire jumper from the main board to the master volume pot break-out board that I can hack!
So the 'splice out' to a loop-out/loop-in pair of 1/4" jacks can be made right on the cable that links up to the master volume pot.
Since the AX2 is in stereo (and my looper isn't) - I only spliced in to the Left channel - but with stereo jacks, you could splice both wire 1 and wire 4 just as easily.
I also used a 1/4" jack with a switched contact on the receive jack (it switches as you push in the plug) - so that the receive defaults to getting the 'shorted' send signal - if you don't plug anything in the the loop.
This way the amp runs normally with no loop cords plugged in.
But plug a cord into the (upper) new 'loop-out' jack on the back panel to connect to the looper input, and another cord from the looper output to the (lower) new 'loop-in' jack on the back panel, and its magic!
Uh, here's a few pics along with the schematic mod:
If you need more info (if anyone on the planet is still using this paradigm-breaking amp, and wants to mod it), just ask - I'm an EE :-)
BTW, it works great! I can record a loop with rhythm guitar effects on, and then play the loop back to the power amp while I solo (in stereo) with lead guitar effects!
Re: I added an Effects Loop to my old AX2!
by KaZoom1618 on 2013-01-14 14:16:18
I forgot to mention - to remove the amp chassis from the case, you remove 2 screws from each side of the amp, and 4 from the top (including the 2 that hold on the handle).
Then slide the chassis out of the back of the case - no need to remove any knobs, but of course, you unplug the AC cord, speakers and floorboard first!
Then remove the 'bottom' plate to access the circuit boards by removing the 9 screws.