Thursday, October 31, 2013

PolyLAB Update 10/31/2013

Welp, the global cutoff and resonance knob switching has been completely redesigned.  The amount of parts needed for something so simple was just bugging the hell out of me.  So, I ended up ditching it all together and going with simple rotary switching.  Now it will have independent controls for each.  The Cutoff and Resonance will each have a 6-pole 2-throw Rotary switch which will send it either to it's local pot or the dual gang global pot.  The nice thing about this is not only is it waaaay more simplistic, but it will allow individual control of each parameter, such as if I want to have control of but cutoffs but with 2 different resonance amounts.  I'm thinking that could be a pretty neat feature.

I finally wired up the Saw to Triangle PCB to my working Soundlab.  Holy crap!  The low end that comes out of this thing now is incredible!  This synth absolutely needs this added to it!  I'd highly suggest adding this to yours if you have one.  The circuit is easy to wire up to some perfboard.  I used a 3PDT toggle to switch between the 3 waveforms.

Here's a wiring diagram for the 3PDT:

Here's some pics of it in place.  Double sided sticky foam is great!:

Ambika with 6 SVF Filters For Sale [SOLD]

I have a freshly built Ambika for sale.  Asking standard price of $1100 + shipping (I also have it listed on eBay for $1150 to cover their damned fee's).  It will come with the Power Supply and 4GB SD Card.  Send me an email if interested.

Tuesday, October 22, 2013

PolyLAB Update 10/22/2013

Slowly coming along.  I think the PCB design is finished.   I crammed everything onto 1 board.  It will have the following:

  • Modulation Destination Switching
  • Cutoff & Resonance Switching (for global and local controls) with a Mono/Poly Switch and LED indication
  • Portamento
The Portamento was an addition I just did last night.  There are 2 on the board actually.  1 for each voice.  There will only be 1 Amount Pot.  It will be asymmetrical, meaning there will be a switch to choose between slide into note only, slide out of note only or slide in and out of note.  Should be a pretty cool feature.

Friday, October 11, 2013

PolyLAB Update 10/11/2013

So much for keeping the PCB costs down.

The global Filter Cutoff & Resonance pots were a bit more involved than I thought, but this is a section that I feel the synth must have.  Pretty nice looking PCB though.  I still have to go through and label everything, but I'm hoping this and the Mod Bus boards will be ready for fab next week.

Sunday, October 6, 2013

PolyLAB Update 10/6/2013

Well, the more I looked at the design of the Mod Bus, the larger the part count was getting, so I scrapped the original idea.  I worked it down to just  3 CV Mixers and let the rotary switches handle all of the switching.

The LFO Wave Selector rotary switch stayed, but the destinations were reduced to OSC 1, OSC 2, Filter.  There is now 2 Mod Source/Destinations.  The Source will just be a standard Toggle switch between LFO & S&H.  Both toggles will wire to the Amount pot.  From there it will wire to the Destination Rotary switch to be sent to the Mod Bus Mixer PCB.  This is a much simpler design and will keep the PCB cost low.  With the previous design I was pushing the cost for 3 boards over $100.  This new design is about $25 for 3.

On Friday I put an order in for the Saw to Triangle Generator!  I also designed and ordered a small board for the rotary switches.  Instead of having to solder a bunch of flying leads, they will all be connect to a molex connector.  Nice and neat.

Now that the Mod Bus was redesigned, the Global Control Panel will have to be resigned.   I may also be replacing the 2 MFOS panels and putting both + the Global Panel on 1 piece of sheet metal.  I had a thought to redesign the layout of the 2 Soundlabs and move all of the patch points between the global control and the 1st Soundlab.  Oh, and I will be replacing all of the banana plugs with 3.5mm jacks.  The main reason for doing this is so I can connect it to my dotcom and eurorack modular easier.  Banana patching between different power supplies is a pain because it does not carry the common so I would have to have a dedicated banana plug that was wired to common to bind the commons between systems, as well as have a separate unit with banana to TS Jacks (I did build one, but with more than double the patch points, it's just not worth it to keep the banana jacks).

That's all for now.

Note the INPUT labeling is wrong. Instead of LFO or S&H it will just be 1 or 2 and its destination as both busses will be switchable between LFO and S&H. 

Wednesday, October 2, 2013

Finally got around to writing the About page.  Forewarned, it is extremely winded!