Help solve this problem

[bluevelvet]

... or educate me why this won't work. I am attempting to wire 2 pickups so the 1st one is on all the time and the 2nd can be switched 3 ways: 1) off 2) parallel to the first pickup in phase 3) series to the first in phase. All of my attempts have involved a DPDT 3-way on-on-on with 6 poles. Just like doing a parallel/split/series on a humbucker, but where the 1st pickup is the 'split coil'. This is the only schematic I found that relates to my goal.

The schematic is a common one. The hot of the 1st pu to the lower right post. The ground of the 1st pu to the lower left post. One of the 2nd pu wires to the middle right post. The other 2nd pu wire to the middle left post and to the upper right post. The upper left post left empty. The two 2nd pu wires can be swapped to change phase. The 1st pu is a p90 and the 2nd is a mini humbucker. My wiring so far involves small aligator clips, and I have a DVM set to dc and 200k ohms.

The problem I am encountering is that the parallel and the split work fine and I get appropriate readings on them with the DVM, but the 2nd pu will not turn on in the series position. The DVM reading is identical to the split reading. With the guitar through an amp and tapping on the pickups with a paperclip, nothing out of the second pu. I have tested the switch with a regular 4 lead humbucker and it works fine. I have wired the 2 pickups in series with no switch and gotten an expected combined reading. I have tried a different 2nd pu, flipped the magnet on the 1st pu, hooked up all the ground wires to a pot, left the grounds unconnected, swapped hot and ground on the 1st pu, swapped the two 2nd pu wires. All no change.

If anyone has any ideas, knows what is happening here, knows a workaround, or a different solution to the same end I would greatly appreciate it. Thanks for your time, Steve

ps: I almost made my user name AtWitsEnd because of this!

[JohnH]

Hi and welcome.

Nothing leaps out of your description, and also you say that it worked with a regular humbucker, so you must have the switch correct.

are you wiring like this?

www.seymourduncan.com/support/schematics/hum_1vol_series-split-par.html

where red/white would be one of your pups and green/black the other?

have you got the two coils of the humbucker connected at the mid point?

I'm curious as to why you wan this switching arrangement? why not have the two pups available separately?

John

[jhng]

It might be that you've got the switch the "wrong way round". In the middle position of a "on-on-on" what you have is one side of the switch connecting "up" and the other side connecting "down". The attached pic should work.

The thin yellow lines on the switch show what should be connected in the middle position.

Also, (apologies if this sounds really patronising!) it may be that two of the clips are touching and shorting out the second pickup in the series position.

Hastings

[UnklMickey]

johnh said:

...and also you say that it worked with a regular humbucker, so you must have the switch correct...

hmm, that seems logical.

so why don't things work with the mini?

did the regular HB have it's connections separate from ground?

does the mini have it's (-) connected to the shield, causing it to always be connected to ground?

are you certain you are using the same connections on the switch in both cases?



unk

[bluevelvet]

Thank you all for your replies and welcome. Much appreciated. I feel my replies to your questions will be lengthy, so I will cut as much out as possible.

I am wiring just like the Seymour schematic. The 1st pu (always on) is a PRS p90. It has hot and shield. The 2nd pu mini humbucker is a Seymour. It has 4 leads plus shield. The 3rd mini that I used as a test is an Epiphone mini that has hot and shield. In my hookup the p90 hot goes to the lower right post. The p90 shield goes to the lower left. The mini has the red and white to each other. The green goes to the middle right. The black has a lead to the upper right and the middle left. Swaping green and black changes the phase. When in the guitar the mini shield went to the pot. (guitar has one concentric pot vol/tone) When using the DVM I simply touched to the lower left and lower right posts. When in the guitar through an amp the lower right post went to the output and the lower left post went to the pot. I cleary heard the difference between in phase and out of phase when in the parallel mode. After testing for phase through an amp I removed the switch from the guitar for easier testing. The Seymour was the humbucker I used to test the switch using the red white black and green from it. The DVM readings were in spec. I soldered inch to inch 1/2 extensions off of each post to make sure the alligator clips didn't touch. I put the mini shield to nothing and to the pot. I tried 'wrong way round', no change.

"does the mini have it's (-) connected to the shield, causing it to always be connected to ground?"

I sure hope so, its a brand new pickup. The cover is soldered to the base in two places. I have never taken a humbucker w/ a cover apart. I had the guitar wired where the DTDP allowed me to choose the p90 by itself, the p90 and the mini in parallel, the mini by itself, and it worked fine. If it works fine in parallel, wouldn't also work fine in series. This whole DTDP 'circuit' goes to the bridge side of a 3-way gibson style switch. Another PRS p90 is in the neck position, so when the mini is switched out, the guitar is a regular 2 pu, 1 vol, 1 tone. The mini sits in the middle.

Which brings to where its at now. I'd like something to work. The important sounds for me are the p90 by itself and the p90/mini in series. I have a DTDP 2-way on-on 6 pole. I'm thinking I can do an in series in phase w coil tap and be done w/ it. Any schematics?

Why you ask. Not a common hookup, but the mini is not cut into the center between the p90s. It is next to the bridge pickup. I love the sound of firebirds. Had one. I am one of many poor quality Gibson stories. Bye, firebird. No money for another. I had a cheap all mahagony guitar (think Special) and didn't mind cutting a hole in an odd place. Let's put a mini in. The Epiphone mentioned above. Mini adds alot of glassey, mellow textures. Nice. Another guitar better at it. Not the firebird sound I was hoping for. The guitar evolves into a slide guitar. Slightly raised nut and bridge. p90s are great, mini doesn't add much anymore. Mini also is not as comfortable in height as I would like. It is as high as the p90s. Get Seymour. High output ~16k. Put it down almost flush w/ body. Lose the height, same relative volume output. In parallel very similar to the Epiphone. Its own warm sound by itself. OK, not great. Tried series. Originally because for slide I like to hit the first preamp tube a little harder and it would be nice to take one less stomp box. Great sound. Now I want it. If you made it this far, thank you very much for your time, Steve

[mlrpa]

Is it possible that you have the connections backwards? (Some of the on/on/on that I've had, are opposite in the center position. ie:
X O or O X
X X or X X
O X or X O

(I know, Fancy diagram. Ignore the "or" and see the X as the contacts when the switch is in the center position. )
Also, the switch could be bad. It happens.

[jhng]

bluevelvet said:

In my hookup the p90 hot goes to the lower right post. The p90 shield goes to the lower left.

That sounds wrong to me. If the P90 hot and shield are both permanently attached to output and ground I don't see how it can work in series.

Here's a hunch: try swapping the P90 hot and the mini hot.

Hastings