UNVERIFIED. This layout is traced from Andrew Sharp's stripboard drawing and checked in Copper Bottom against Ray Wilson's schematic - the netlist below is written from the schematic, and the copper agrees with all of it. It has not been built from this file. Build it once, fix whatever fought back, and this banner comes off.

Weird Sound Generator

Ray Wilson's MFOS WSG · Andrew Sharp's stripboard layout · Traced by Onion Madder · Mess O' Pedals

Ray Wilson's Weird Sound Generator is where a huge number of people built their first synth, me included. Ray's page carries a stripboard version by Andrew Sharp, as two pictures. This is that layout as a Copper Bottom file, so the editor can walk you through it part by part, and checked net by net against Ray's schematic. Two voices of three oscillators each on one CD40106, mixed into an LM741 filter, with eleven knobs and seven switches on the panel. Ray's own page, with how it all works in his words, is the MFOS WSG rebuild.

The layout file is the guide

Like the rest of the stripboard shelf, the build document for this one is the file itself: ↓ Download Weird_Sound_Generator.json - import it into Copper Bottom and the editor gives you the board picture, the placement walkthrough, the electrical checks and a printable build sheet, all from the same file. No coordinates are written out on this page on purpose: the editor is the viewer, and a number typed twice is a number that can drift.

Comparing it with Andrew's picture? The strips, the cuts and the wiring are his. A few parts stand a hole or two from where his picture has them, on the same two strips, so that every body has room, and C9 and C10 are added across the supply. The two diode bands are set from Ray's schematic: band toward the switch pad.

The netlist

Quoted verbatim from the layout file. It was written from Ray's schematic, not from the board, so when Copper Bottom says the board matches it, that is two separate records agreeing. The capital names are the ones on Ray's PCB, which is how his panel wiring drawing labels every wire.

The off-board wiring

Twenty-seven pads leave the board. The pad names are Andrew's; the MFOS name beside each is the matching point on Ray's PCB, so Ray's panel wiring drawing works for this board as it stands. Lug numbers are Ray's.

How it works, in one breath

Each voice is three Schmitt-trigger oscillators from the one CD40106. The wacky oscillator runs at audio rate; the zany one is slow and wobbles the third, the weird oscillator, through a transistor that shunts its frequency pot, and the zaniness pot sets how hard. The wacky oscillator can join the mix itself (Wacky Too) or gate the weird one through its diode (Wackiness), and Unusual grounds a 1 µF on the way to the transistor's base, so the wobble slurs instead of stepping. Both voices sum into a filter round the LM741, tuned by the two cutoff pots and sharpened by the resonance pot. Ray tells it better, with jokes, on his page.

Things to try

• Ray's mods. The WSG mods page is his; every one of them lands on the same named points, so they apply here
• If it fights back. Ray's troubleshooting page is written for the PCB, and the MFOS names in the table above are how to translate it
• Turn it off while it plays. S3 opens and C11 carries on for a moment, which is why Ray named the switch what he did

The Weird Sound Generator is Ray Wilson's, from Music From Outer Space, 2007 - see the MFOS WSG rebuild. The stripboard layout is Andrew Sharp's, contributed to Ray's page. Traced into Copper Bottom and checked against Ray's schematic by Onion Madder.