MFOS !6 Step Sequencer Front Panel and Pcb




Introduction: MFOS !6 Step Sequencer Front Panel and Pcb

About: Electronic Design Engineer

Having been put off by the amount of wiring required to finish the MFOS 16 step sequencer with the Variclock board, I decided to make a PCB for the front panel! As it measures a full row of eurorack I could not etch this at home so I went to to get a few professionally made. These turned out perfectly. I had used 3PCB before for my Replicator module. For this project I went for a sexy black with white text. It takes less than a week to get them posted back to the UK and you can check its progress at each stage of the fabrication process. I have now received the fabricated test front panel to check all the holes line up and everything looks great. I could only to get the test made with no text printed so the one in the picture has a decal label on it. Unfortunately theses panels are not cheap and with the text have a minimum order of 10. The print quality is excellent with this company as you can see on my Replicator module. If you are interested please leave a comment.

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Step 1: Here Is a Pic of the Boards

I had to shoehorn the rotary switches in as they have slightly more depth than the rest of the components as you can see hear,

Has anyone seen ant slimmer ones?

Jarno:Ouch, you will need to change those rotary switches, that's going to fail eventually. PCB's arent meant to be bent, unless they are the flex pcb variety.
A big cutout in the pcb's with pads around, hooking up the rotaries with short lengths of bare wire?

Altitude909:Not crazy about the encoders either. Are those the prototypes or the production boards? You really need a better solution there.. Grayhill series 25L sit really low

Me:Yeah to use these switches I really need to have slots to cutout a square around the switches and connect to the main board via another IDC. If only those switches didn't have the clips at the bottom as its only a couple of mm out. I wonder if they could be glued together and the clips taken off?


whats the PN/make of that part?


Those switches are near impossible to heightmatch with board mounted 3.5mm jacks. And 16mm pots are more suited to them.


thats a good question Altitude909 but its just what i had in the drawer lol I think it might be possible to modify this switch to fit, I have a few ideas. I only need to rescue 2mm! I'll give it go in the next couple of days.

I made an experiment by using an old soldering iron to weld each half of the switch housing together. This enabled me to remove the retaining clips.
I wish they made them like this. I had mounted my components before I had a front panel as I was far to impatient to wait to see if the pcb worked out. If the components were loaded into the front panel first it looks like there would be enough play in the solder pins to keep a straight board. I suppose all advancements have gone into digital encoders

Maybe consider a hole in the PCB that will allow the rotary to fit through. Then use the bit of PCB from the hole as the rotary mount with headers to connect it to the main board. Just add mills and breakaway tabs so the rotary mount PCB can be snapped out. This way you don't have to do any stunt soldering of all of the other components.


Unfortunately there is not enough space for 2 more IDC connections and the cut out slots. I might have to invest in fume extractor and supply modded rotary switches.


Very nice sequencer. Count me in for 1.


Just to be clear efexor this is just a front panel and control pcb. This attaches to the MFOS sequencer boards found here

Step 2:

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    2 Discussions


    1 year ago on Introduction

    Hi - Do you think that soldering in the rotaries first and then the others (pots/jacks) after there would be enough room to solder others without having to bend the pcb at all? How much for a panel pcb and panel?
    Do you accept paypal?


    4 years ago

    Thanks for sharing this!