Phase switch not working

[Stinger]

Replaced my old Tele bridge with the Jerry Donahue model. Had a phase switch on it (DPDT with the pickup leads on the center terminals and the outside terminals cross wired to change the phase and then leads from the bottom lugs going to pot and ground, just like tje image below which I hope shows up). Unsoldier the old pickup leads and soldiered the new ones in place. Put it back together and the phase switch only worked on one side, completely dead on the other. By itself or with the neck pick, just one side of the switch working. Got a new switch and wired it in. Same thing. Weird. Any ideas, I can't imagine how a single coil would only work one way but I ain't no expert.

Any ideas?

 

[Artie]

Re: Phase switch not working

If the new pickup has a baseplate thats both grounded and connected to the "normal" ground wire, that will happen. You may need to isolate the ground wire from the baseplate.

Edit: Its been awhile since I had my JD, but I believe that it does have the grounded baseplate.

 

[Stinger]

Re: Phase switch not working

If the new pickup has a baseplate thats both grounded and connected to the "normal" ground wire, that will happen. You may need to isolate the ground wire from the baseplate.

Edit: Its been awhile since I had my JD, but I believe that it does have the grounded baseplate.

Yes it does have the based plate and I kept the ground wire that was wedged under the bridge and connected to the controls ground (old pickup had a phenolic baseplate).

So I removed that wire and it fixed the switching problem but now in that postion on the switch I get HUMMMMMMMMMMMM! Especially when I touch the strings but even when not it's BAD. How can I ground that out?

Thanks

 

[LJ King]

Re: Phase switch not working

The pickup grounds to the strings. When you flip the switch you are making your strings a hot connection instead of ground.

You need to remove that ground - the one from the pickup wire that is soldered onto the brass plate. Jjust undo the connection from (black wire?) to the brass plate. Then your pickup wires will be without ground.

Then solder a separate wire to the brass plate on the pickup and into the control cavity to the back of the volume control.

This is why a phase switch is easier on the neck pickup.

 

[Stinger]

Re: Phase switch not working

Great! I'll be trying that tomorrow then. My bridge is a SD Jazz and I have it going to the three way switch so I get series/parelle/tapped. I guess I could run those pu leads through the phase switch first and then through the tapping swtich and then wire the bridge as normal to the pot and ground.

I really like the tone options this gave me previously and would hate to lose the out of phase sound I got. Not quite a strat inbetween but definately close.

Would do it today but gotta watch them ribs out on the grill!



Thanks for the help!

 

[LJ King]

Re: Phase switch not working

Great! I'll be trying that tomorrow then. My bridge is a SD Jazz and I have it going to the three way switch so I get series/parelle/tapped. I guess I could run those pu leads through the phase switch first and then through the tapping swtich and then wire the bridge as normal to the pot and ground.

I really like the tone options this gave me previously and would hate to lose the out of phase sound I got. Not quite a strat inbetween but definately close.

Would do it today but gotta watch them ribs out on the grill!



Thanks for the help!

???

You really meant that your neck pickup is an SD jazz. Right? Your first post said a JD bridge. I is so confuse ed.

If so then you need to wire it so the phase switch is AFTER the 3-way. The 3-way must not connect to ground. It should "push" the ground to the phase switch instead, meaning you have the TWO wires out of the 3-way (hot and ground) going to the phase switch and after the phase switch only one of those wires is grounded.

Does that make sense?

 

[Stinger]

Re: Phase switch not working

Oops typo, trying to watch the race too!

Sorry. Yes Neck Jazz bridge JD.

Yep, I went ahead with the change and the switched only worked on one side again (as with first attempt using the bridge). Switched it so as you say it pushed the ground to the switch. Works great now!

EXCEPT, I still have a problem I've had since installing the Jazz.

If I have both pickups selected and turned to 10 as I start to roll off the neck vol control the sound picks ups (as I think it is picking up more of the bridge) then it peaks and drops dramaticlly as the bridge just seems to cut out around 8. Opposite as I turn the neck up it peaks around 8-9 and then from 9-10 a roll off.

If if turn the bridge vol down or up it seems normal.

I'm running 250k's on the bridge (single) and 500k's on the neck (Hum;s) could that be the problem?

Thanks

 

[LJ King]

Re: Phase switch not working

Oops typo, trying to watch the race too!

Sorry. Yes Neck Jazz bridge JD.

Yep, I went ahead with the change and the switched only worked on one side again (as with first attempt using the bridge). Switched it so as you say it pushed the ground to the switch. Works great now!

EXCEPT, I still have a problem I've had since installing the Jazz.

If I have both pickups selected and turned to 10 as I start to roll off the neck vol control the sound picks ups (as I think it is picking up more of the bridge) then it peaks and drops dramaticlly as the bridge just seems to cut out around 8. Opposite as I turn the neck up it peaks around 8-9 and then from 9-10 a roll off.

If if turn the bridge vol down or up it seems normal.

I'm running 250k's on the bridge (single) and 500k's on the neck (Hum;s) could that be the problem?

Thanks

Darn I was hoping to catch you before you wired the phase switch as you first described. Oh well at least it is working now.

The volume control problem. With both pickups on and the volume controls maxed getting a drop in volume is normal. Turning one or the other down and getting an increase in volume is also normal - it happens will all dual pickups with separate volume controls regardless of how the volume controls are wired. There is only so much a passive mixer can do.

The drop of volume and increase is because of the change in loading of the pickups as the individual volume controls are rotated. With the neck volume control as it is turned down part of the pot is placed in series with the neck pickup. The neck pickup has a lower impedance than the volume control so this action isolates the neck pickup from the rest of the circuit. This isolation continues until the resistance of the pot is roughly equal between the center lug and both sides. Since you say this happens at 8 I assume you are using audio taper pots. At this resistance and impedance center point the overall load on the bridge pickup is reduced allowing that pickup to produce more volume (and highs).

As you continue turning the neck volume down the resistance between the center lug and ground decreases faster which now increases the loading on the bridge pickup reducing its volume - at least with conventional interactive volume control wiring. The non-interactive wiring will keep the volume the same but will still have the peak and reduction effect due to that isolation of the neck pickup and overall load reduction.

This happens on the bridge volume also. You may not notice it as much because the 250K pot will not has as much of the isolation effect as the 500K pot and the overall load would remain more constant.

You can try changing pots to see if you can minimize it but you might find it becomes more noticible on both volumes if you go to 500K. It might be less noticible with 250K values on both volumes but the trade off is more loading on the neck pickup.

Its all a tradeoff.

 

[Stinger]

Re: Phase switch not working

"Darn I was hoping to catch you before you wired the phase switch as you first described. Oh well at least it is working now."

OK I give, why? I have it wired now to the neck -> splitting -> phase switch. I can always open her back up and change something.

"it happens will all dual pickups with separate volume controls regardless of how the volume controls are wired. There is only so much a passive mixer can do."

Hmmmm, I have a Gibson ES-347 and I don't seem to notice it so much then I guess. Much easier to "mix" the pickups using the volume controls without the very noticeable volume dip/peak I'm getting on my tele.

What about a master/blend I hear about some people using?