I'm new to this forum, so apologies if I'm bringing up something that has already been discussed.
I'd like to wire a HSS strat with 2 volume knobs (500K or bridge, 250K for neck and middle) and a tone knob (250K, for both neck and middle) and a 5 way switch.
I'm very new to wiring and I'd highly appreciate some help regarding this matter. I've only found schematics for a master tone knob for all 2 pickups, but I'd only want the tone knob wired to the neck and middle only, no need for a tone knob for the bridge.
The first diagram shows the two volumes, plus a single master tone pot but it is a dual-ganged pot, ie two separate pots on one shaft each with its own tone cap. All you would need to do is to use the lower pot and ignore the top pot. The bridge single would be replaced by your humbucker.
Just one question: Why do you want two volume pots? If it is to be able to preset two different volumes, or match two volumes, or mix pickups, then those are good reasons. But some builders do this just to be able to get a presumed benefit of having the 250k and 500k values for singles and humbucker. I would suggest that that may not be required and there are other ways to address that issue.
This 2 Vol Strat design is one of the unsung harnesses on this site. There are so many stellar designs here.
Son-o and I have, between us, built probably 20 of these. They are a standard test bed for when we are trying different pickups to trial and different pickup combinations. In these test mules we typically enhance the design with an ON-ON-ON DPDT on the Bridge humbucker, giving local series, cut-coil and local parallel on that pup. That allows us to get a meaningful view of the tonal ranges of a given pup, perhaps for later installation in an alternative design.
Even without that Ser-Sing-Para enhancement the design is demonstrably flexible, especially adding the System series in N*B, (N+M)*B and M*B options to the standard Strat 5-way selections. The feature you rarely find in Strat style designs is the ability to dial up gradations of sounds in the combinations. For example you will find a number of designs with OoP options. That sound is nearly comically thin when both pups are in the signal stream in equal proportions. However the feature becomes an altogether serviceable enhancement when merely a smidge is dialed into the mix, adding clarity without the extreme frequency cancelling offsets of full OoP. The mixing feature is critical to really opening up the options in to tonal variations.
Great option, moderately difficult but not daunting.