PO Modular Build Notes

Hey everyone,

Just finished my PO-modular build and wanted to share some notes for anyone receiving theirs and starting the build.

Tools - A Torx-8 driver is provided with the kit. Needlenose pliers are a must. The pliers will be necessary for screwing the standoffs to the frame as they are difficult to hold and screw into at the same time. A set of snips, and a second larger T-8 driver is also recommended. The snips are for cutting the standoffs in half when you need to attach the power distribution module. The second T-8 is useful for tightening the modules in place.

Time - Set aside at least 2 hours for this if you have all the tools required, or longer if you don’t have the tools. I took about 3.5 hours total to build mine because I didn’t have needlenose pliers or a second T-8 screwdriver when I started, so I had to finish the build in a second session the next day. I think you could build this in under an hour if you have good, grippy needlenose pliers available, and use the method of attaching modules I describe below.

Bending & Screwing the panels - The paint is going to crack, so don’t worry about that when it happens. When bending the faceplate, I recommend keeping only bending the sides about 80° (not the full 90°) before you put the modules in. This allows you to more easily install the modules before you do the final assembly. I also recommend pre-screwing all of the holes with one of the screws using the larger T-8 driver. It is a pain in the ass to try and attach the front panel without pre-screwing the holes before final assembly, especially with the provided T-8 driver.

Modules - As you’ll see in some of the build videos, the most efficient method is to remove all the modules and install the standoffs on the frame first.
I recommend this order of operations:

  1. Add all standoffs to the frame
  2. Install the power distribution module (cut the standoffs in half)
  3. Install all modules. Order doesn’t matter except that the speaker should go in last (tuck the speaker wire between the module and the faceplate; it’s easier than trying to squeeze it in the gap between modules).
  4. Wire everything into the power distro panel. I recommend starting with the lower modules since those cables are a bit tougher to place, and end with the upper modules.
    (Note: The power module can be plugged in anywhere on the distro panel. I used the end socket closest to the LED so it is easier to unplug if I need to remove the panel.)

Screw it all together and power it up - If you’ve pre-screwed the holes in the panels this is easy. If you haven’t, you’ll want to do that before you try to assemble everything. Then plug in the batteries and I used this power adapter - note: it isn’t the correct size for the plug, but it does work for me. YMMV but you may want to find a better option as another user didn’t have success with this one with interchangeable bits and it works to power the PO-400 pretty well.

Secondary notes:

  1. The output of the PO-400 mixer is mono (TR) output, even though it ships with stereo (TRS) cables. You’ll need a converter or signal splitter into a mixer to get a stereo sound out of it. I’m using a Hosa Knucklebones splitter into a Maker Hart Just Mixer L/R so that I can use headphones with it. (Obviously there are easier methods but this is what I had available)
  2. Some of the potentiometers are out of alignment with the holes and are difficult to turn. I haven’t done anything about this yet, but from what I’ve seen you may need to use a rotary tool to widen some of the holes in the faceplate if you run into this issue.
  3. You may want to get some extra patch cables. TR cables work fine.

I would not recommend widening the holes, mine had a few tight pots, so I removed the module and very carefully used a flat blade screwdriver to align the pots by moving the metal pot body slightly, you can kind of wedge it between two pots and kind of cajole it to move probably a fraction of a millimetre, but be very careful. Needle nose pliers can also be used.


Hi, would appreciate it if someone could suggest a pair of snips that would suit the purpose of cutting the plastic standoffs. I’m in the UK. Thanks!

I’ll try that with mine and see if that fixes the alignment. I didn’t try that at the time because I was nervous that I might disconnect them and I didn’t have a soldering iron available.

Most wirecutters should do the trick. I used something like these: https://www.amazon.com/Stanley-84-105-6-Inch-Diagonal-Cutting/dp/B0001IW89W/ref=sr_1_3?keywords=wire+cutters&qid=1554109305&s=gateway&sr=8-3

Yeah its a little nerve wracking but just be super careful and you should be fine, main thing is not to slip and catch any surface mount parts.

Thanks and cheers for the build notes too - very helpful!

Not calling you a liar or anything but I bought that power adapter based on this post and it is not working for me unless I apply pressure to the jack in a very specific position – I believe it may be slightly too small (4mm barrel as opposed to 4.75mm). I’m curious – does it work without issues for you?

Hey, so yeah mine works with no issues, I thought it was fine since I haven’t had any problems even with the size difference.

I can look for another adapter on amazon, I just listed this one because I already had it from another project…

Interesting! It must be an issue with my power supply unit then. Just wanted to put another data point out there for other people reading/searching for solutions.

1 Like