The diagram isn't drawn up yet but it's pretty straightforward.
+/- go to the corresponding lugs of the DC jack.
IN goes to Input Jack Tip
OUT goes to Output Jack Tip
Each jack grounds to their nearest GND pad
The two 3PDT breakout boards are direct pin-for-pin connections.
See this build report for an example:
Very straightforward build, @Robert said it’s a little tight, and it is, so you should definitely put the 3PDTs in first, solder only one leg of each pot, and then get everything test-fit first before tightening all the nuts and soldering all the pots (which I guess technically you should do for...
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