A parallel project starts.. Components are on their way, panel is designed, boards are here…..
it will be an MFOS Sequencer!!!!

For more info, you can look here at Ray Wilson’s MusicFromOuterSpace (and he will host Mr. Braska on his US tour!)

This is a first step towards completing the board. The odd part is that one of the ICs is soldered on the bottom side. This was a clever thought Collin had as it reduces bridges to 5 total from at least 15. As I realized yesterday, I had put no values to most of the components, so tonight, an updated version of the board will be placed online with the values written.

Not all R2R resistors are in place as I ran out of them. So it might be finished tonight. The thing is that soldering resistor ladders is SOOOO BOOOOORRIIINNGGGG!! I should have used a resistor array.

Another thing I should mention is that the board can work with both AVRSyn 16 and AVRSyn 32 firmwares and processors. So I placed a female pinheader in the place of the crystal and I can test both of them before commiting to AVRSyn 32 and it’s 16MHz crystal

Hope to have updates soon….

Collin Mel and myself , have designed a PCB layout for AVRSynth, instead of doing it on perfboard. It hasn’t been proofed and debugged yet but I am on the process. If you feel adventurous and/or lucky, you can download the eagle files from here
and try yourself!. Please do tell me about possible bugs you may encounter.

I exposed the photosensitive board covered with a transparency with the PCB layout printed on. I used two transparencies, one stacked on top of the other for extra opaqueness. Still there is a little UV light going through, you may see it on the photos as the copper is a little spotty. No electrical flaws though, but I think, another layer would do a better job.
I developed the exposed board with a solution of 1 teaspoon of pipe cleaner (branded TUB.O.FLO locally) but which contains NaOH. When developed, I etched it using a 14% HCl solution (also a cleaning product) and dropped in it a small cup of concentrated Peroxide. (Named localy “Peridrol”). If interested I can delve in much more detail on the etching process. Just be ware of the fumes and liquids, so work in a well ventilated area, stay AWAY from children (you and the chemicals) and store them out of their reach. These chemicals are highly toxic and caustic and I don’t want to be held responsible for any misusage of the components.

This is how it looks while ethcing.. Beware of them bubbles. They stink and for a reason. DO NOT inhale close to them.

This is the finished PCB, without any components on it. I will post photos of the component mounting process and hope it works the first time

When this is finished, a core midibox module will take care of the midi messages that are needed to have access to the AVRSynth32 functions that are not available through it’s pots. (such as cutoff, resonance, ADSR params etc.)

I MUST finish it. (and of course, it’s panel

Both are midibox core modules, both are working even with the slight fixes made on the right one . One serves now as the brain for the sequencer and the other one for more experimental stuff. (That is: my non-working programs