First boards nearly completed: digital board and PSU. Next will be the DMUX board so I can start testing the various voltages as well as the digital and digital-to-analog sections.
Author Archives: lmarka
Parts arriving
First batch of parts arrived. Board and components for the PSU and Digital boards, SMD resistors and capacitors, and most components for the DMUX board. Also, Curtis chips were ordered from Alfa and are on their way! Connectors and several random items, such as the alphanumeric display, were already received.
DMUX board update update!
At this point the DMUX board should be under production; however the issue with different libraries for the SMD ICs made me wait until the components arrive prior to sending the board for production. In the mean time, I decided to make a few modifications: now, Ground, +15V/-15V, +7.5V/-7.5V and Noise are all sent to …
In production!
Ordered most of the parts by now, and sent the Power Supply and Digital boards for production. Will wait until the ICs I ordered arrive because I am not sure which of the SMD IC footprints I should use; Kicad has updated the libraries from version 4 to 5 and now I am not sure …
DMUX board update
After some consideration, I removed the ground plane initally placed in 100% of the bottom layer of the board. Reason for that was the constatation that for this board, pouring a large ground was producing lots of “dead end” ground areas, which may be even worse than no ground plan at all; one GND and …
Common analog
Just found out I had a mixup with my Kicad libraries. I was founding it odd that only the Pinhead connectors were being rendered in the 3D view. Turns out that when upgrading from Kicad 4 to 5, the libraries have to be deleted and the new libraries have to be added – a manual …
Digital Board
Not much change from the original. The first board I designed; tried to keep the component distribution more or less the same as the original. Had to guess the size of the original board by measuring the drawing using the pins in the CPU as a “ruler”… In this redesign, all ICs now have decoupling …
DMUX board
3D rendering of the redesigned DMUX board. Power connector is now a standard ATX, as used in PCs. Power supply is supposed to deliver some 70W in total (I think… do not have the exact current drawn by the synth figured yet. Use of modern components should reduce this amount). The ATX (Minifit) and Microfit …
Voice boards
3D rendering of the current design for the voice cards. Changed trimpots for VCO 1 to see the difference in layout before deciding in one type over the other. Relocated power connector further inside the board so the cables would not interfere with the board to the left. Still considering moving all other trimpots (total …
PSU
Think the logical starting point is the power supply. This will be needed for testing and debugging all other boards, so started it is! Just ordered the transformer, similar to the one pictured above; fan will be a standard PC cooling fan, much quieter both accusticaly and electrically than the original fan. I am rethinking …
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