How many ways can an HB1 be wired and what are the effects?

[lumgimfong]

...on a 4003 bass...
I notice 4 wires coming out of each pup. Black/red/clear/blue.
Just wondering what the options are and the effects of each way of wiring them.

Right now I have it wired like this (This 4003 bass controls are V/T/selector - with two HB1's).

[blueflamerick]

You can wire them like any humbucker, so you can split the coils, making the pickup single coil, and you can run the humbucker in series or parallel.

[lumgimfong]

What sound differences are there between series and parallel?

[espidog]

This very generalised description applies to all dual-coil humbucking pickups, not Just the HB1.

Parallel: this gives the flattest, widest frequency response. Words like "detailed", "balanced" and "civilised" are applicable.

Series: this will give a bigger amplitude (louder/ballsier) signal, with more of a midrange "hump". Compared to parallel, you'll notice that the top end is more rolled off, less detailed.

The exact difference in sound between one state and the other will be determined by the design of the pickup. Some humbuckers exhibit relatively little difference in sound, with the pup maintaining its essential "voice" across both states; with others it's like night and day!

I always think that if you've got a 4-wire humbucker in an instrument, there's really no point in NOT installing a series/parallel switch. Not doing so is like having a turbo-charger on your engine and having no way to switch it on.

[jps]

All the basses I had, and other I have played, such as the 7ender Roscoe Beck Jazz Bass, that had S/P switching for their humbucking pickups always sound best, to me, in the parallel setting. I prefer the wide frequency range and clear, non congested tone of single coils and parallel coil humbuckers to the thick, midrange heavy (in most cases - HB-1s do not exhibit this "quality", IME) tone of most humbuckers. As usual, YMMV, yadda yadda.

[espidog]

Just as a side note (a parallel thread, you might say - pun intended!), I've even applied series/parallel switching to the single coil bridge and neck pups in my 4003. Sacrificed the stereo option (which I never used, TBH) in order to do it, but the extra bit of sonic versatility is well worth it. With both pups switched in series, I get a lovely bit of thickness and bottom end boost. Still sounds like a 4003 though!

[lumgimfong]

So is mine series or parallel the way it is in the pic?

[jps]

So is mine series or parallel the way it is in the pic?

Frankly, it's impossible for me to see what's going on in your photo.

[lumgimfong]

How bout this?

[espidog]

I would have to see a closer-up/much sharper version of that shot to be 100% certain, but based on what I can see there and assisted by this official RIC schematic showing which wire colour does what on an HB1, I'd surmise that the blue wire from each pickup is commoned up to the shielding of the wire and soldered to the case of the selector switch (i.e. ground) and the red wire from each pup is going to its respective pole of the selector switch.

The black and clear wires will be connected together inside the bulge of that black shrink-sleeving

...which tells me that currently, each of your HB1s has its coils wired in series. This is the stock arrangement for an HB1 as it leaves the factory.

I'd be much happier/certain about the wire colours if I could see a very sharp macro shot of the switch.

[aceonbass]

How bout this?

5D516032-B8FF-478E-82DA-92F4882D37C4.jpeg

Your pickups are running in parallel. Any time you run a pair of pickups into a master volume or separate volumes at the same level, you will experience a mid scoop caused by phase cancellation. This is why I always run separate volume controls, even if I'm running into a single tone control. Replacing the pickup switch with a balance control will eliminate this effect (which I don't care for) if you bias one pickup or the other on the balance control.

[espidog]

To avoid confusion here...

Each of your HB1s has its coils wired in series. When you have the selector switch in the mid position, the two HB1 pickups are in parallel with each other.

Whenever I've spoken to you about "series/parallel" switching, I've been talking about the coils of a given pickup, not the relationship between the two pickups.

[lumgimfong]

Thanks for the responses. I think I understand.
The "series" or "parallel" refers to when using two pickups together at the same time?
Each pickup itself is already "series" alone?

So it is basically wired like a 4004 as it is now?

[espidog]

So it is basically wired like a 4004 as it is now?

I can't answer that one, as I've never seen a wiring schematic for the 4004.

[jps]

Thanks for the responses. I think I understand.
The "series" or "parallel" refers to when using two pickups together at the same time?
Each pickup itself is already "series" alone?

So it is basically wired like a 4004 as it is now?

Yes.