More fun with the Screamin' Demon - Partial Split (Like PRS)

[ErikH]

I've been using the Screamin' Demon for a long time now in my old Frankenstrat, in both the neck AND bridge positions. The one thing I've never tried is with it split. My first concern was the output since it's wound with 43AWG wire to 10K (mine measure 10.1 and 10.4) so split would be way low. Anyway, I had searched for others' opinions on it split and even found a video on YT demoing it full series mode and split. Not bad, but I was still concerned with the output.

I stumbled across some posts talking about partial splits, like what PRS does. This involves putting a resister between the red/white wires and ground. PRS uses 2.2K for the bridge and 1.1K for the neck. Different resistors have different results. One guy that has a SD in the bridge ended up using 1.8k. What the resistor does is it allows some of the shunted coil to remain active. It's not completely shunted to ground. That little bit of active signal remains mixed in with the other coil as normal. So, you end up with a single-coil sound, but with slightly more output than what a full split would give.

After playing with a few values on the multimeter, I settled on 2.2k for both neck and bridge. That yields a single-coil of about 6.5-6.6k. The 1.8k resistor yielded around 6.2k. The Screamin' Demon fully split is only 5-5.1k. Quite a difference. Both of mine split to the hex coil and the neck pickup is oriented the same as the bridge so the hex poles are closest to the neck.

I have to say, I'm very happy with the results. The neck has a very convincing tone. The bridge tone is somewhere between full bridge single-coil and notched position with bridge/middle singles. Nice usable sounds from both. There is a drop in volume but it's not a massive amount. Having a little boost on tap is still not a bad idea if one so desires, and any split could be that way really.

With pickups in the vintage output range, I can see this being a good option for setting up splits. I have a WLH neck set up to split in another guitar and it's at 4.1k. Next time I change strings I'm going to add a resistor to bring that up a little bit, maybe to 6.0k. The Custom Custom in that guitar splits to 7.2k and has plenty of output.

Tip: If you use a single DPDT On-On switch for this to spit both pickups at the same time, do not share the same resistor with both. There will be some bleed from one to the other depending on your pickup selector switch. I found that out doing the tap test before closing it all up. Use one resistor for each pickup.

 

[Masta' C]

That's some great info!

 

[BluesIsBlood12]

With pickups in the vintage output range, I can see this being a good option for setting up splits. I have a WLH neck set up to split in another guitar and it's at 4.1k. Next time I change strings I'm going to add a resistor to bring that up a little bit, maybe to 6.0k.

I put a WLH set in my PRS that has the partial split, and they work very well. This should be the default way that people split vintage output HBs. My 59/Custom hybrid works fantastic with the traditional split, since it's splitting to the Custom coil, which is pretty hot.

 

[ErikH]

I put a WLH set in my PRS that has the partial split, and they work very well. This should be the default way that people split vintage output HBs. My 59/Custom hybrid works fantastic with the traditional split, since it's splitting to the Custom coil, which is pretty hot.

Good to know. Thanks for the feedback on that. Though PRS uses 1.1K for the neck pickup, I'll most likely go higher to get closer to 6.0K.

 

[playas]

This is cool, thanks for describing it, never knew what people meant when they talked about partial splits. Where is the resistor wired exactly?

 

[skelt101]

This is cool, thanks for describing it, never knew what people meant when they talked about partial splits. Where is the resistor wired exactly?

My PRS CE-24 has Master Volume, Master Tone and 3-way switch. The Master Tone has a DPDT Push/Pull for the partial split. The resistors are wire to the common (middle) terminals and ground. The down (push) terminals are empty, and the split coil is wired to the up (pull) terminals. Here's a diagram from PRS:
https://www.prsguitars.com/documents/prs_ce24_wiring_schematic.pdf

 

[ErikH]

My PRS CE-24 has Master Volume, Master Tone and 3-way switch. The Master Tone has a DPDT Push/Pull for the partial split. The resistors are wire to the common (middle) terminals and ground. The down (push) terminals are empty, and the split coil is wired to the up (pull) terminals. Here's a diagram from PRS:
https://www.prsguitars.com/documents/prs_ce24_wiring_schematic.pdf

Yup, exactly. For Seymour Duncan humbuckers, between the red/white wires that are together and ground. I used a single DPDT toggle switch rather than a push/pull but it's wired the same way as seen on that PRS diagram.

 

[playas]

Cool, thanks. May well test it out on a pearly gates.

 

[allstarrme]

Prs has spent a good amount of time getting these tuned so their single coil sounds don’t have a large volume drop. They even have some pickups partially tapped for this rather than using resistors on a few models. It’s good to see some companies still try new stuff to pursue tone rather than tradition.

I need to go through and add resistors to the auto splits on my 5 way switch. It may not make the Ernie ball pickups sound any better but will make the split tones much more useful.

 

[hamerfan]

I prefer to use higher resistors and skip the cap. I get higher volume and fuller sound. I like it on the edge between a single coil and bright humbucker with the partial split. Found 3.3 k for the neck and 5.6k for bridge quite nice.

 

[ErikH]

I prefer to use higher resistors and skip the cap. I get higher volume and fuller sound. I like it on the edge between a single coil and bright humbucker with the partial split. Found 3.3 k for the neck and 5.6k for bridge quite nice.

I wondered how higher resistors would affect the sound. Which cap do you leave out? The cap in the PRS diagram link above is the tone pot cap. I don't see a cap in the actual partial split wiring.

 

[hamerfan]

There is a .033 uF from the coil joint to the push pot. I skip that and have bass contour tone pot (OBL eq4000) instead.

 

[ErikH]

There is a .033 uF from the coil joint to the push pot. I skip that and have bass contour tone pot (OBL eq4000) instead.

Yeah, that's the tone cap for the tone control.

Edit: Cool tone pot mod.