build it

rev1b

###BOM:

BOM (for rev1.b, rev1)
note this doesn't include part #s for the breakable, round/machine pin headers and sockets. re knobs: options include sifam (w/ "encoder caps"), rogan 2s, and cliff K85 (+ suitable cap).

###component overlay (bottom):

jumpers high-lighted (in blue), red: ignore/don't populate:
- silkscreen (rev 1b) (pictured above)
- silkscreen (rev 1)
in case of doubt, check the change log.

###notes:

generally speaking, it's a very easy + quick build. you can follow the values printed on the board, except:
- ignore the pads labelled 29, 79L05, and (if present) LM4040-3; none of this is required. the LM4040-5 is required. (†)
if you have a pre-rev.1b PCB, as per BOM use 100k where it says 49k9 (around the MCP6004): see below.
other than that, no particular precautions. that said, make sure to look at the notes below re:
- OLED pins/aluminium panels (these shouldn't touch !).
- jumpers (you need two).
- teensy pin 13/LED: must be removed when used with PCBs prior to version rev.1b; details below.
(†) (to generate the negative offset, rather than use a LM4040-5, you could alternatively install a -5V regulator (TO-92) where it says 79L05 (PCB top), but not both! (of course). IF using a 79L05 (SEVEN-NINE-OH-FIVE) regulator instead of LM4040-5, you also have to leave off the 1k resistor marked with a * (!)).

###populate:

this is how it should look with the all the parts installed. note the socket for the teensy with extra hole for the DAC pin (1x14 + 1x14 + 1 extra pin):
pin header labelled clk/DAC: connect the two pins where it says DAC, ie the middle and top-most hole (cf picture above) (unless you have a teensy 3.0, in which case there is no DAC: the jumper serves the purpose of switching output #4 between the DAC and a digital output pin (29)).
the second jumper (simply use wire) goes between the square pin and the middle pin:
and as mentioned above, use 100k where it says 49k9. (if it says -- silkscreen fixed in rev.1b)
NB: in the above picture, a 79L05 was used (hence the unpopulated 1k* and lm4040 pads). as per BOM, use 1k + LM4040.

###jacks:

###encoders:

if using the Bourns ones, they're not tall enough. you have to solder them onto the top side of the board, so that they line up with the jacks:

###oled:

use a low profile socket. you'll have to trim the pins somewhat (or replace the header) so as to make things fit / line up with the other components (ie jacks, encoders):
if using an aluminium panel, make sure the OLED pins don't touch the panel! (ie cut them flush with the pcb)!

###finally. prepare the teensy:

you have to cut one trace, to separate V_USB and the external/eurorack PSU. this is the trace:
PCB versions prior to version rev.1b: these lack a suitable external pull-up to override the LED, so the onboard teensy SMD LED needs to be removed for right encoder switch to work properly. in most recent versions, the 10k resistor right next to the teensy 3v3 pin takes care of that. for older versions: don't worry, your teensy will be ok, the LED is entirely superfluous. you can easily identify the LED, it's near pin 14/A0. just snip it off with the tip of your iron. if you have a pcb labelled rev 1.b, this is no longer required (as noted).