Hello dear friends,
I recently completed a build of a very nice phaser module, it’s called Model P by the wonderful Maffez.
It sounds great and is based on the SSI2140 IC, to of which are used in the module, providing 8 stages in total.
Since I bought a few extra 2140s just in case, I started to wonder whether it would be possible to utilize 2 more ICs in order to double-up the stage count.
I asked Maffez about this, and he said that it’s easily doable, by building a daughter-board and connecting it to the original PCB.
Now I’m no expert PCB designer (I wouldn’t even call myself a novice…) but this could be a nice project, I think.
So, my question is: would anyone here be interested in helping me out with this? I could start by designing an initial schematic / board and then posting it here for review.
Here’s the schematic of the original module for reference.
(A great, easy build, well worth the time)
Thanks 
I did something similar with the MFOS 8 stage phaser, I added 8 more stages just by replication of the existing stages and inserting it in series with the existing 8 stages and taking taps at stages 12 and 16 in addition to the 4 and 8 stages.
So looking at the schematics you just have to build U1 & U3 sections again, connect the output of your first section U3 FPOUT to the input of the new section and the output of the new sections to the old FPOUT opamp U2. The question is what to do with the spread, I would test with the same connections as U1 and U3 to the new stages first or ask the designer what he suggests.
The feedback pot connects the the FPOUT of the opamp U2.
2 Likes
Hey, thanks for stepping in
The original designer (Maffez) wrote that the additional stages would share the same spread settings as the originals. Which is a bit of shame as I would prefer spreading them around (or better yet, have the spread controllable by CV) but I would also be happy with simply doubling up on the current phase shift depth.
Here’s what I currently got, I assumed that the connection between the two boards involves wiring to pins. I’d love to know if this is fine or needs any adjustments.
