Strange Pot Behavior

[GSFV]

Not specifically a Guild question, but I'm hoping y'all can help. I recently picked up a new guitar. It's a jazzmaster shape, but has 2 Lollar p90's instead of jazz master pickups. 3 way toggle, individual V/T configuration. I've noticed that the pots do not respond like any of my other guitars. I like to blend the volumes in the middle position. (Both pickups, bridge full volume, neck down to 8, etc). But I find almost none of those tricks/techniques yield anything close to what I'm wanting. There's very little change as I twist the knobs. But! When using the the individual pickups there are changes.

Also, I just noticed tonight (perhaps related????) that the volume and tone seem to be coupled?...decoupled? I don't know how to describe it completely. But if I turn the tone all the way down on the neck, a la woman tone, and then adjust the volume I can hear all the highs come back in. And It's like the tone was rolled all the way back up. I even tested this by rolling volume down to 8 and then tone all the way up and then all the way down. Absolutely no change in sound what so ever. This same thing happens when toggle is down for the bridge.

I thought I was going nuts but I just checked and my (trusty) Starfire V. It works as expected (no surprise there!). The tone knobs work no matter what the volume is set to. The middle position allows plenty of variation using a volume or tone. So...Is this something that is typical for p90's? I wouldn't think so, but I've never had a p90 guitar before. Is this a different way to wire up the V/T configuration? I'm at a loss. I like the guitar, pickups sound killer, but I hate these pots. Or at least the way they behave. Any insight it appreciated (hopefully my meager descriptions will ring some bells).

 

[Guildedagain]

It's not the pots, it's the wiring. It sounds like the middle position is wired out of phase?

 

[walrus]

Boy, I took the thread title all wrong! I thought someone had a video of me in the '70's!

walrus

 

[Midnight Toker]

It's not the pots, it's the wiring. It sounds like the middle position is wired out of phase?

From what I understand, it was very common w/ older Guilds to be wired like that. My 66 T100-d has the out of phase “quack” in the middle position. I love it and would never change it!

 

[GSFV]

Boy, I took the thread title all wrong! I thought someone had a video of me in the '70's!

walrus

I was hoping to get some laughs, lol.

 

[GSFV]

I don’t think it’s out of phase. When I manipulate the volume in the middle position there isn’t the jump back to normal and change. It’s like the volume does almost nothing… and then the change in volume overrides the tone. So when volume is down tone does nothing.

 

[BradHK]

I would take off the pickguard and take some photos of the wiring configuration. Post those here and you will get some expects who can help. It sounds like the wiring layout is creating the behavior you are describing but without seeing where each wire is going it is hard to be specific regarding a solution.

 

[GSFV]

 

[GSFV]

Tried to upload, not sure it will, or if it’s a good angel. But it’s all I had on hand.

 

[Walter Broes]

Not the pots, not the pickups, but the way it's wired up. From the tone pot behaviour, it sounds like your guitar might have what's commonly referred to as "50's gibson wiring".

 

[GSFV]

Did the photo get uploaded? And if so, can you confirm that’s what it is?

 

[SFIV1967]

Did the photo get uploaded? And if so, can you confirm that’s what it is?

Well, typical 50s wiring is this:



Now when you look at your guitar... I'm assuming the bottom pots are the bridge pots and the half visible pots are the neck pickup pots? Or is it vice versa?



...you will notice that the signal input goes to lug 2 of the bridge volume pot and the signal output also goes from the same lug 2 to the switch.
Now your lug 1 from the bridge volume pot goes to lug 3 of the bridge tone pot. And your lug 2 of the bridge tone pot goes via the 22nF capacitor to ground.
Lug 3 of the bridge volume pot is correctly grounded and lug 1 on the bridge tone pot is correctly open.

However without seeing the neck pickup tone pot completely I'd say your neck pickup tone pot is wired differently, I'd say more correct. It looks like on the neck pup volume your signal from the pickup goes to lug 1 and lug 2 goes to the switch? Also not sure where lug 3 from the tone pot connects to.
So please post a picture of the neck volume pot connections.

Ralf

 

[BradHK]

i was thinking the same thing, I have not seen the wire from the pickup and the wire going to the selector switch soldered to the same lug on the same pot. I would expect the black wire from the pickup to be wired more like this below:

 

[SFIV1967]

i was thinking the same thing, I have not seen the wire from the pickup and the wire going to the selector switch soldered to the same lug on the same pot. I would expect the black wire from the pickup to be wired more like this below:

Exactly!

Ralf

 

[GSFV]

What is pictured below are the bridge controls. I know that the neck controls function in the same way the bridge do. I will see if I can get a picture later today.

But it sounds like y’all are suggesting I move the black wire down one lug. Is that correct?

 

[Rocky]

But it sounds like y’all are suggesting I move the black wire down one lug. Is that correct?

Yes. And possibly move the white wire from the tone pot to the center lug. At least I like it that way.

 

[SFIV1967]

The thing is, there is no pure right or wrong as long as the signal path is somehow logical. So it depends what a player wants to achieve.
Maybe this link also helps a bit:

6 Powerful Ways To Wire Up A Tone Pot

There are multiple ways to wire up a Tone Pot - here are a few different variations on Tone Pot Wiring that will make your life easier!

www.fralinpickups.com

What I just noticed is that in Westerly Guild wired the volume pots on the Starfire V/VI actually backwards, means the signal from the pickups went to the middle lug of the volume pot and the output to the switch was connectd to lug 1 of the volume pot.

So in that case you could leave the black wire from the pickup at the middle lug but you have to move the white wire to the switch from the middle lug to lug 1.

I don't have a wiring diagram for the Newark St. Starfire V unfortunatelly but it might look like the Westerly diagram.



But other Newark St. models are wired as Rocky likes, so maybe the Newark St. Starfire V follows that as well. Signal to lug 1 and output from the middle lug.



Actually I just found that 2017 Newark St. Starfire III diagram GAD made in his review, so indeed also the Newark St. Starfires seem to be wired backwards on the volume pots (means signal to middle lug and output from lug 1).



Ralf

 

[Prince of Darkness]

Also from GAD.
The wiring on a Guild S300 is actually pretty interesting because though it looks on the surface to be just like any other two-humbucker four-knob guitar, it’s actually not. These guitars are wired in a way that never clicked for me even after owning one for over 20 years because the difference only manifests itself in the middle position that I never used as a 20-something guitarist in the “bridge pickup or GTFO” time that was the ’80s.

On a typical two-humbucker guitar with four knobs such as a modern Les Paul, when playing in the middle position if you roll one of the volumes to zero in the middle position, the guitar will go silent. This is the case on my 1997 Guild Bluesbird and my 1998 Starfire as well, but this does not happen on a Guild S300. Why? Because of the wiring.



This feature is called decoupled wiring because the volume pots are not coupled together like they are on a typical modern Les Paul. If you look at my drawing, you’ll see that the pickup connects to the middle connection on each volume pot. On a modern Les Paul, the pickups and the selector switch connections are swapped on the volume pots which makes the entire thing interact differently when the middle position is engaged.


Decoupled wiring is cool because each volume control is more useful in the middle position, but the problem with decoupled wiring is that the tone darkens considerably when the volume is rolled down.

 

[Rocky]

Decoupled wiring is cool because each volume control is more useful in the middle position, but the problem with decoupled wiring is that the tone darkens considerably when the volume is rolled down.

It's also harder to play early Who, Ronson-era Bowie and Tattooed Love Boys with it.

 

[GSFV]

Alrighty!! So… many many thank you’s to everyone. I believe I got it sorted. I’m going to upload a couple photos that are more detailed of the original wiring. BUT! I did move that black wire down a lug. And the controls are behaving much more similarly to what I’m accustomed to. So for now it shall stay in this new configuration.

I REALLY wish I had played before I did this. It’s been a week since I played and I swear the base or starting tone has changed ever so slightly to allow more highs? Like I said. I wished I’d played before swapping it over. I could put it back and test, but I’m not the best with a soldering iron and I actually really like the way it looks. Still pretty clean. So again, it stays for now. lol.

Thanks so much for the help!! No way I would have gotten there on my own.