February 2011

MFOS – Weird Sound Generator

Sometimes you don’t want to have to spend hours researching designs and finding parts to build a project… sometimes you just want to buy everything you need at once, solder it up, and have fun without the worry of troubleshooting your design. At those times a kit is perfect and in this case that’s just what I did.

I’ve posted about MFOS before. They manufacture a number of kits from entry level to advanced synthesis kits. I decided to go with the ‘WSG’… or Weird Sound Generator. Ray Wilson has some excellent designs that are really fun to put together. I managed to get this up and running in a weekend without any hassles and it sounds great. It’s basically two squarewave generators with LFOs and a resonance filter. If your just starting out this is perfect… and even though I’ve been doing this for a while it was still a ton of fun. Ray’s taken all the hard work out of the process and made DIY synthesis simple, straight forward, and well documented.

He provides all the documentation you could need including wiring diagrams, pcb templates, schematics, block diagrams, and parts lists so I won’t duplicate that here. I’ll just add some comments on the build and a video of the finished project at the end of the post…

Here we have the parts list laid out…

Most of the components have been soldered to the PCB at this point. All the parts are included in the kit and none were missing.

The finished PCB sans ICs.

I used a aluminum enclosure from an old broken gemeni turntable mixer I bought off of ebay. I’ve had great luck finding things like this for 10 bucks or less sometimes and they’re perfect when you need spare knobs, op amps, or enclosures. I just flipped it upside down and took of the rubber feet. Holes were drilled using a step bit (these are a must have for drilling good holes in aluminum enclosures).

Here is everything wired up.

This is the PCB finally wired up. One complaint about this is that the holes on the PCB for all the wiring are placed all over the PCB which makes for really messy wiring. I found that extra care was required to make sure the wiring didn’t bend too much and come detached from the PCB. It seems like using headers would be a much easier way to go about this the next time around.

When I put this together I first soldered the hookup-wire to the board, then to the components on the panel which makes it really difficult to keep things neat and tidy. Next time I will wire up the panel first, then complete the board, then make my connections to allow for a cleaner layout.

Just a tip for beginners… don’t shrink the heat shrink tubing until you’ve tested your work and are certain it works. It’s a major irritation to have to remove heat shrink tubing after you’ve already… well, shrunk it.

Jörgen Bergfors and the BERGFOTRON

The Bergfotron is the masterpiece of Jörgen Bergfors, an exceptionally gifted member of the Swedish Analogue Sympathists mailing list (SAS). Jörgen has been creating modules, enclosures, PCBs, and all things synth DIY for over thirty years and believe me it shows. I don’t think any description fits his skill set better than ‘Master’. He is simply one of the best.

The Bergfotron site has tons of pictures detailing every coceivable aspect of his process. He hand makes the actual panels with mounting studs and graphics… The attention to detail is truly above and beyond.

He covers theory and actual practice, has schematics, circuit board layouts, procedural details and covers just about every aspect of the process in his writings. One thing he doesn’t have though is a well laid out web-site so navigating and finding everything isn’t always that clear. But really, who cares.

Here are a couple examples of his work… they speak for themselves. I definitely encourage you to take a look at his site. I’m of the opinion that regardless of what you’re doing DIY related you can get some tips from him on how to master your craft. If his pictures of his work don’t convince you then what are you doing reading this?

Bergfotron-Super-Syncussion

Carsten Toensmann and the ‘Analog Monster’

Carsten Toensmann is the man behind the “Analog Monster“. For the past decade or so Carsten has been slowly building analog modules himself with a help from the book “Formant-Pro MSS2000”. This book, which is out of print and only available directly from the author in electronic form. I have no more details on the book but if the results of Carsten’s work are any indication of its content then it must be awesome.

I can really only say one thing… Carsten is amazing.    Here are a couple pictures of the complete project in its current form and two of the modules. Two out of 25!

The completed build…fantastic work.

The Quad ADSR Front Panel…

…And the Quad ADSR Board. I wish there was a hi res of this so we could really see his attention to detail. These boards are all hand/home made… no using Gerbers and bulk manufacturers in China like PCB Express and others.  The thought of drilling all those holes makes me squirm.  However, Carsten apparently prefers to drill all the holes instead of dealing with things like this

The Octave Divider front Panel…

And the hand made board…