Wednesday, July 23, 2014


Late night exploration with the TTSH.  Pulled the MFOS WSG out of a dust pile for this one.

Wednesday, July 16, 2014

Werkstatt Mods cont.

I found that the 1 octave keyboard ranges from 0-3v.  So, when a standard 1v/oct is applied, the scaling is nowhere near 1v/oct.  This is a bummer as I wanted to break the keyboard connection to the VCO so I could send the incoming CV through the glide circuit.  In order to make it work (as far as I can see) is either add a 4053 to switch between 2 different trimmer/resistors that are both set for either 1v/oct or 3whateverV/oct the Werkstatt keyboard is  (linear?) ... or, ditch the keyboard completely and re-purpose the glide to go through the VCO exp IN only.  I don't like either of those options.  I'm ok with adding a panel to the back for a row of 3.5mm jacks, but I'm not a fan of switches and pots sticking out hear and there.  I'd rather just add glide externally instead.

On the plus side, I designed a panel for the row of jacks I'll be adding to the back. Most of them are just taken right from the header patchbay.  Instead of a straight VCO out, I'll route the square and saw waves to separate jacks.  I'll more than likely remove the jumper on the PCB between the VCO and VCF and normal it to the Audio IN.  This way I can send audio through without the VCO mixed in.  Having the saw and square waves separate I can route those through modules and add other VCO's, then through a mixer and back into the Audio IN on the Werkstatt.  The overall plan is is to keep everything relatively simple but still useful.  The thing that makes the Werkstatt so much fun is its simplicity.   I could go crazy and add a daughter board with a 2nd VCO with saw/square/triangle, a mixer section, a noise source, S&H, etc etc etc all with SMD parts, then create a new case with knobs and switches galore....  but why?!  I have plenty of other synths that do that.

I may add a midimplant though.  We shall see.

EDIT: of course I messed up on the panel above.  Labeled VCO Square out as Tri.  Bummer I already ordered it.  Oh well.  I wanted to add another hole so I can have an out for each of the LFO wave anyway.

Once I nail down a panel design, I'll offer to do this mod if there's enough interest. 

Thursday, July 10, 2014

Moog Werkstatt Sequence

Now that I have the gate in done I can really play with this beast.  Still really bummed the PCB is 3U.  To big to fit between the eurorack rails. :(

Moog Werkstatt-Ø1 Mods

External Gate IN:

I finally found some time to start poking around inside the Werkstatt.  First on the list is adding a Gate IN to trigger the envelope.  I followed peff's idea of using a voltage follower for the Gate IN.  I did a breadboard test and had it running in minutes.

I was wiring the Gate IN directly to the sustain switch and found that in order to have it work properly, the trace coming from the keyboard will need to be cut.  I found a small spot just before the gate is converted into a trigger.  here's a schem (oh, and I used a TL072:

All of the parts fit nicely on the kludge area on the PCB with pleanty of room to spare.  You'll notice I added some capacitors.  These are just .1u bypass caps at both voltage inputs to ground.

I know I'll be adding more, so at the moment I have the jacks just dangling out of the back through a small slot just above the power jack.  Eventually I'll drill out the case and mount them inside.  One thing to keep in mind is BE MINDFUL OF YOUR SOLDERING IRON!  I wasn't paying attention and it got a bit too close to the sustain switch.  :(  Hopefully Moog will be nice enough to supply me with a part number.  It works, just a little melted.

Friday, June 27, 2014


one of these came today...

I was really bummed to find that the PCB is almost exactly the same size as a Eurorack front panel, which means it's to big to fit between the rails. :(,  But, there is pleanty of room below the PCB at the back to add a bunch of 3.5mm jacks (with some case drilling).  I'm really digging the size and addition of the 1 octave tact switch keyboard.  Most synths this size require an external keyboard for control, but this I can grab and play while tweaking on a modular patch.  Fantastic!

Thursday, June 26, 2014

LSW #7

So, this one doesn't technically qualify as part of the video series, but I am using a couple modules that I assembled.  It was more due to the excitement of getting Peaks in the mail today.  Finally some simple drums!  Plus more modulation choices.   One day Peaks will be fully released.  Until then, you can watch this video and eat jelly.

Wednesday, May 21, 2014

MFOS Soundlab Love

I did a demo video of the MFOS Soundlab Mini-Synth MKII back in december of '12. Well before I started LSW.  It just made it to the home page over at Music From Outer Space!  It's quite an honor and privilege to grace the main page of one of the predominant Synth DIY figures/manufacturers.  The information available on his site is invaluable & indispensable.  It has helped me understand both general and specifics pertaining to synth building/designing.  Thanks Ray for the props!

and if you've missed it, here's the video: