Have had this module ready for quite a while now, and finally get round to uploading. Time flies, eh!
A SSI2140-based phaser it is!
This module was kind of inpired by the Symetrix Phase Filter, a semi-oblique rackmount phaser built around two SSM2040s. The trick of this box was that the frequency control between the two phaser blocks (of 4 stages each) was uneven, resulting in a thicker swoosh. There are great Eurorack phasers, for the 2140 too, and Neil Johnson has some great SSI2164 phaser design, yet curiosity about the specific Symetrix take got the better of me, so after a too bulbous first version, I opted for an 8HP module with a decent set of controls.
Module Description
You have a single audio input with level control that is scaled for hitting the phaser a bit too hard when fully cranked up (this can soudn broken in a good way), some modulation CV input and an output. For controls you get manual frequency setting and resonance, as well as speed and amount setting for an inbuilt triangle LFO. The MOD socket is a breaking jack, so when you plug external CV in there, this replaces the internal LFO (pre-amount setting) with whatever you plug in there. Since I wanted the board underneath is a bit dense, that’s enough for I/O and controls.
Build Info
This phaser uses two SSI2140 ICs, so soldering TSSOP it is! Apart from that, there isn’t anything really difficult or overly complex. For SMD caps Panasonic ECHUX ppt caps work really fine, but honestly, any other will do. The trimmer on the back set the CV balance between the two x4 allpass blocks. In the centre position the frequency response of the two blocks are the same, and the more you tilt in one direction… you get it 🙂
Gerbers, BOM, Schematic
Complete production files are here. These have been built by at leat three folks I know of, so they’re tested and go!
schematic for glancing over stuff
That’s that for now. If oyu have anny suggestioms/questions, just email.