UPDATE
Well, the old board was frozen and I will not continue working on it, it began to malfunction and after trying to troubleshoot it without luck, I got frustrated
If you want to see the last pictures I took of it, here are some (including a prototipe analog board to make tests)
http://www.japiwebcam.com.ar/japi/megad ... oard_dead/Now that I have the 4851's (thanks Synthex for sending those) I will try to build Synthex v2.5 all in one
Yesterday I lost 4 hours trying to print the inputs pcb to scale. The main board printed right away as I used the pdf's made by other users that are in this forum. So I printed, transferred to pcb, etched. The transfer was good but in the input pcb I lost some of the bottom part. I just used a marker to redraw that part. Certaintly not cute but effective. I also corrected two shorts: there was one in the main board, in the lines that comes from the 4851's (pins a,b,c). There should be all a, all b and all c together, but not abc together. Mine was abc together, due to the thin copper lines. I just scrapped it (hope that's the word) to fix the short. There was another in the inputs board, don't remember wich one, but same cause, same fix.
Today (sunday) I made the holes and cut the inputs pcb.
Picures here
http://www.japiwebcam.com.ar/japi/megadrum/08-newboard/