MK_SEQ/Schematics/schematic_bugs_v1.md
2024-07-27 19:10:52 -07:00

2.4 KiB

Assembly notes: WARNING: There is a connection on the v1 board between R25 and R1, probably a result of KiCad adding junctions during a component move. This needs to be severed. See this image of the bad trace.

  • Do not connect the Normal pin for Pause (J19/J18); the schematic is incorrect
  • the current 12-position rotary switches are actually 2p6t, which means only six different step counts are available until the replacement arrives
  • Wiring SW15 (once/stop) and cascade out is easier done via skywiring; only one cross-board wire is needed, vs 3 if the PCB is used.
  • LEDs go in long leg down (from the front)

Schematic notes:

  • C1 is too small for a 1uF capacitor. 1uF may be unnecessary, though.
  • C10, C14 too small for film; is film needed?
  • Fix R25/R1 connection
  • One socket connection is on the wrong side of the board, adding an extra cross-board wire that shouldn't be so hard.
  • In general, try to avoid putting any UX connections on the larger board underneath the smaller board.

Try:

  • C1: enlarge footprint; a box film cap for 100v is smaller, but not that small

  • C3 and C4 could use slightly larger spacing on the thru-holes.

  • C7 is a ceramic 104 power cap like C5, C6, C8, C9, C11, C12.

  • C10, C14 is a guessed value; could be other values, ceramic may work, test debouncing. Maybe enlarge footprint if needed.

  • Resistor footprint could stand to be +1mm between legs

  • Trim 5mm from vertical for both panels, to make fitting inside a case easier. Or 10mm if it can fit; losing the bodge area.

  • Don't put R8 so close to R26

  • D36/R47 too close

Testing before powering up: ~Ins: Clock In - diode to U2-3 Clock In Normal - 1k to U2-8 (AND NOT short to U2-10) Clock Rate - variable resist +6k between U2-8 and U2-9 Reset Sw - when pressed, short +12V and Reset In socket Reset Socket to U3-3 = capacitor measurement roughly 15nF (has a resistor as well) Once/Cont When in Cont mode shorts Casc Out normal to Reset In Pause CV In - U1-13 (can get at from top when assembled) Stop Switch - 10 ohms between U1-14 and U2-1 when off, more like 1M ohms when off Single Step - 12V through 10k Ohms to U-1-14, more like 1M when off Glide In - ~27K to U3-8? No, transistors maybe activate?

Outs: Clock Out - 1K to TP5 Gate Out - 1K to U2-14 Case Out - Diode from rotary pin 13? CV Out - 1K to U3-7

Debugging issues:

Glide section not working right, just pegging the output to +10V? Clock POT is too small; need more than 100k to get below 200bpm~