Faulty PTB-wiring (confused as to why)

[Tor]

I have G&L Legacy I'm wiring up for the PTB wiring, following this diagram:

My wiring:

When plugged in, there's a tiny bit of output. The amp needs to be turned way up.

Tried troubleshooting with this methodology: http://www.guitarnuts.com/technical/electrical/trouble/strat.php

Three findings:
- middle+bridge and middle+neck do not yield quite the expected results (about 3.6K, compared to the 4.9K from each of the single coils
- resistance only increases to 30K when turning volume down, until it decreases all the way again
- resistance increases to "infinity" when bass pot is turned down

The way I see it, either:
- the diagram is incorrect, or
- there are some components that may be faulty.

Have you got any idea?

Thanks.

 

[stevie_bees]

Re: Faulty PTB-wiring (confused as to why)

I had some issues finding a good diagram to follow when I wired mine up. I've swapped the wiring out recently, but I'll see if I can find how I had mine wired.


Sent from my TARDIS using timey-wimey talk.

 

[Tor]

Re: Faulty PTB-wiring (confused as to why)

Thanks, that'd be awesome!

 

[Artie]

Re: Faulty PTB-wiring (confused as to why)

It's hard to read the cap values in the diagram, but typically, they'd be 223. Not 222. That just means that instead of .022uf caps, you're using .0022uf caps. That shouldn't affect the output though. So, there must be some other problem.

 

[Funkfingers]

Re: Faulty PTB-wiring (confused as to why)

That bass pot appears to have seen some soldering iron action. It may be damaged internally, either physically or by heat.

 

[Funkfingers]

Re: Faulty PTB-wiring (confused as to why)

In the schematic diagram, the cable carrying the signal from the selector switch bifurcates BEFORE either of the tone pots. In the OP's photographs, the signal bifurcates at the input terminal to the treble roll off pot.

I interpret the former arrangement as parallel and the latter as series.

 

[hamerfan]

Re: Faulty PTB-wiring (confused as to why)

In the schematic diagram, the cable carrying the signal from the selector switch bifurcates BEFORE either of the tone pots. In the OP's photographs, the signal bifurcates at the input terminal to the treble roll off pot.

I interpret the former arrangement as parallel and the latter as series.

In my book the OP did it right. A series connection would happen if he used the second lug to leave the pot to the next pot.

 

[Tor]

Re: Faulty PTB-wiring (confused as to why)

It's hard to read the cap values in the diagram, but typically, they'd be 223. Not 222. That just means that instead of .022uf caps, you're using .0022uf caps. That shouldn't affect the output though. So, there must be some other problem.

Hi Artie,

The diagram is very difficult indeed, but it's the best I could find. The PTB wiring means that one pot controls the treble (223), and one controls the bass (222)..

 

[Tor]

Re: Faulty PTB-wiring (confused as to why)

That bass pot appears to have seen some soldering iron action. It may be damaged internally, either physically or by heat.

Yup, I haven't been too kind to it. But would such a pot cause almost no output?

 

[Funkfingers]

Re: Faulty PTB-wiring (confused as to why)

The bass tone pot lies in circuit between the pickups and the volume pot. As a test, disconnect the two white conductor wires from the tone pot. Temporarily connect them to each other. Under these circumstances, do you now get the full signal?

 

[Tor]

Re: Faulty PTB-wiring (confused as to why)

The bass tone pot lies in circuit between the pickups and the volume pot. As a test, disconnect the two white conductor wires from the tone pot. Temporarily connect them to each other. Under these circumstances, do you now get the full signal?

Will try tomorrow, thanks!

 

[stevie_bees]

Faulty PTB-wiring (confused as to why)

I've tried to boot up my old MacBook as it had a couple of alternate PTB diagrams on it, but no joy. I have however mounted the wiring on a laminated piece of card so that I didn't have to desolder everything. I'll get a pic and post it tomorrow. I didn't have any issues with mine


Sent from my TARDIS using timey-wimey talk.

 

[ItsaBass]

Re: Faulty PTB-wiring (confused as to why)

Artie, the 222 code is correct for the PTB bass control. A normal 223 code is used for the treble pot (which works just like a normal tone pot on a guitar).

OP, out of curiosity, are you using the correct pots? IIRC, the volume should be 250K (A), treble should be 500K (A), and bass should be the oddball 1 Meg reverse log ("1MC" or "1M REV A").

P.S. Positions 2 and 4 should be lower in resistance than positions 1, 3, or 5. Placing resistive components in parallel (like you are doing in positions 2 and 4 on your switch) results in lower total resistance than the resistance of either component alone.

 

[Tor]

Re: Faulty PTB-wiring (confused as to why)

Sorry for the late response here, haven't had much time for tinkering lately.

I tried to leave the bass pot completely out of the circuit, but the same result applied. I had to turn the volume of the amp way up to get any output.

I am unsure about the bass pot, not sure if it's an oddball, as you imply it should be. I cannot remember if I swapped out all the pots 2-3 years back or if these are the originals..

 

[stevie_bees]

Re: Faulty PTB-wiring (confused as to why)

This was how mine was wired when I took it out of my Legacy. I mounted it on a laminated piece of card so that I could keep it intact in case I wanted to drop it back in.


Sent from my TARDIS using timey-wimey talk.

 

[Tor]

Re: Faulty PTB-wiring (confused as to why)

Thanks! Seems as if the wiring routing is a bit different here. I will have to study this pic more closely this weekend. Thanks again!