Series-single and parallel-single switching with DPDT?

[cassius987]

I realize they aren't on-on-on (they're merely on-on) but I figure there's a great opportunity to take advantage of 4-conductor switching with the DPDT pots RIC used to sell. (Anyone know where to get them in the right dimensions anymore, by the way?) I know Dane Wilder does something like this already with a coil tap.

My ultimate goal is to wire my HB-1 pair as RWRP single coils when tapped and the neck pickup being a parallel humbucker, while the bridge pickup a series humbucker.

I figure the best way to wire the series-single is to send wires 1+3 to the middle switch lugs and wire a bridge between the lugs in the "down" position so these form an end-to-end link with the switch down. Wire 2 is the hot and would go straight to the pickup selector switch. In the up position, wire 1 would go to ground, and wire 3 would not do anything or go to ground (doesn't matter I think). Wire 4 would also be wired to ground independent of the DPDT switch as this is the role it will play for the series humbucker. So wire 2 is hot, wire 1 is ground of the single coil mode in the "up" position of the switch. The external shield is always wired to ground.

As for parallel in the neck position... the single coil needs to be 3 hot and 4 ground for RWRP purposes with the other pickup when it's also in single coil mode. So I think I just need to send 3 and 4 to the middle lugs of the switch and send them on their way to the pickup selector and ground (respectively) from that point. In the down position, wire 1 is joined with wire 4 and wire 2 is joined with wire 3. In the up position, wires 1 and 2 are isolated and no longer in the circuit, as simple as that. Again, external shield goes to ground.

What do you experts think? Will this approach work?

[Kopfjaeger]

Joshua,

I think Dane will chime in here but for now, I can tell you how my 4004 was done. Dane gave me push pull pots on the two volume pots. I soldered the two HB1 wires under the shrink wrap to a wire Dane had provided on the pots. When I pull the pots, I turn the HB1'a into single coil pups. Pretty awesome actually!!

I tend to prefer the neck pup "puilled" while the treble pup is in. With the pots pulled, the HB1's are still super quiet. I also really like the expanded options the VVT set up gives on the 4004.

Sepp

[aceonbass]

Joshua, I haven't tried any parallel-series wiring options yet. I'd have to hear it, then see a diagram of how it's done before I could even render an opinion. I've still got several of the push-pull pots like RIC used to sell if ya wanna PM me about some.

[cassius987]

It sounds like Dane's mod grounds both of the "link" wires of the series connection, which is essentially what my mod will accomplish as well but in a slightly different fashion.

Dane, thanks. I will probably post diagrams later. I don't need any of those pots right now but I am curious what aftermarket part might be similar, if I needed more down the road.

[aceonbass]

That is exactly how my mod works Joshua. The ground wire from the pot lug goes across the lower pair of terminals and then to the side of the pot. The pair of wires soldered together from the HB1's harness go to a lead across the middle pair of contacts. When the knob is pulled, they are shorted to ground, giving you one 7.5K single coil pickup.

[cassius987]

Diagrams:

Parallel:


Series:

[ken_j]

[cassius987]

Thanks Ken. That does switching between series and parallel but I want a series-single coil and parallel-single coil function. Still a good reference diagram though. Thank you.

[aceonbass]

What you could do Joshua, is use a pair of volume push-pulls for coil tapping, and tone push-pulls for your series-parallel wiring. That way you won't be drilling any extra holes in your guard for new switches.

[cassius987]

Thanks Dane. Fortunately I have determined from previous messing around that I really prefer the neck pickup to always be parallel (never series) and the bridge pickup always be series (although parallel is okay in this position sometimes), when they are not single coils. So I won't need series-parallel switching, just one or the other to single coil. Believe it or not I've already got the other two pots assigned to other functions using DPDT switching!

[ken_j]

Thanks Ken. That does switching between series and parallel but I want a series-single coil and parallel-single coil function. Still a good reference diagram though. Thank you.

The difference of sound between parallel and single coil is almost inaudible. I had my guitar wired for series-single-parallel and it was a waste IMO. I ended up changing the switches out and stayed with series-parallel.

From guitarelectronics.com:

With a single 4 wire humbucker, there are six possible modes.
1. Series-In Phase This is the standard humbucker wiring. Maximum power output with strong bass and smooth attack. (hum canceling)
2. Single Coil (South) Just the South coil of the pickup alone. Good traditional single coil tone with a sharper attack. (not hum canceling) Use in combination (series or parallel) humbucker in "North coil mode" or a standard single coil (north) for a hum canceling Strat/ P.R.S. style tone.
3. Single Coil (North) Just north coil of the pickup alone. Almost the same tone as the south coil but slightly different due to its different position. (not hum canceling) Use in combination (series or parallel) with another humbucker in "South coil mode" or a standard single coil (South) for a hum canceling Strat/P.R.S. style of tone.
4. Parallel-In Phase Great single coil style tone with no hum. Best option for clean, bright tone without the noise of standard single coil wiring. Strong treble with crisp attack but lower power output. (hum canceling)
5. Series-Out of Phase Thin "phased" sound with good power. Great for funk. (not hum canceling)
6. Parallel-Out of Phase Thinner "phased" sound with low power. (not hum canceling)

[jps]

The difference of sound between parallel and single coil is almost inaudible.

I think that depends on the particular pickup in question. My experience has shown that the pickup(s) I have had wired up to switch either way produced a more frequency extended, higher-fi® sound in parallel with series being more mid meatier and the output goes up, sometimes significantly, in series, too.

Of course, a lot of this will depend on the input load of the following gear since a series connected pickup will have 4 times the DC resistance of a parallel wired pickup.

[cassius987]

After I spent some time with series-single coil-parallel switching on another bass (using on/on/on switches), I decided that the difference between parallel and single coil is distinct enough to matter to my ears even though yes, they are quite similar. Parallel has a little bit of extra scoop in the mids. It also doesn't humcancel with a single coil, for obvious reasons. The RWRP setup "unbalances" the internal RWRP of the humbucker. However it plays perfectly nice with another humbucker. I really like a parallel neck pickup and a series bridge pickup when running humbuckers.

These mods have to function to fit the need: I know I hate the neck pickup series wiring tone (at the 1'' position it's just a bunch of wool; I think it works better on a Jazz Bass where the pickup is closer to the bridge), and I know for a traditional sound that hum cancels properly when both pickups are on they both need to be single coil. So that's why I'm doing the mods I've listed here. I know for other people something else might be more ideal.