Build #3 DHB-4 fretless

[FaustoB]

Thank Trevor and Simon! very helpful!

Commenting on Simon's points

That 2nd wiring diagram will work, but there are points to note.

....

with the 2nd arrangement, having one pickup on 10 and the other on 0, the pickup on 10 would see a 250k resistance to ground across the volume pots. This will knock off some of the treble and move the pickup’s resonant peak frequency down a bit. So the single pickup sound of arrangement 2 will sound a bit duller compared to arrangement 1.

It’s a bass, so this may not be a problem for you, especially if the pickups are quite bright sounding to start with. The both pickups on situation will sound just the same though.

This worries me a little bit! I agree it's a bass but would love to keep the max tonal range.
I'm installing round wounds to begin with (generally speaking rounds are nice and bright) , but likely to swap to half round or tape wound in the future (which are darker sounding strings, with different tension and feel)

But if you like to have a bright sound available (its easy to loose treble but harder to add it) then you can always use 1Meg volume pots instead, which will give the original 500k resistance to ground through the pots. This will mean that the ‘both pickups on 10’ sound will be slightly brighter than before. Keep the tone pots at 500k.

I like this option! thank you so much. I'm slowly slowly getting my head around electronics but my knowledge is way more limited than this!

Swapping the volume pots is something you can do at any time, so you can see how it goes with the original values and see what you think.

If you want brighter sounds, you can always fit some mini toggle switches so you can have the pickups in series, parallel and split modes. If you don’t want two mini-toggles you can have a common tone control and fit a single 3-position rotary switch for common pickup mode selection, which still gives lots of sound variations.

I like also this option with common tone control with a single 3-position rotary switch for common pickup mode selection!
Losing one tone knob means that I could put the switch right there in the electronics cavity, instead of placing it far away in that pre drilled hole on the opposite side on the body. a long way away and probably a nightmare to fit the switch via the f-hole in the body...