The LP Frampton project - desperate help needed!

[DJ Catchem]

Hey all-

First post, long time reader. To offer a slight background, I'm a drummer by trade, but I've been around guitars long enough that I decided I wanted to have something to play around on. My good friend (Bloodpuppy11...he'll chime in somewhere in here) set me up with a used Epi Les Paul Black Beauty off of Craigslist to get started on.

When I got into it, I discovered that the pots were pretty well cooked (tons of static from touching them at all), so I endeavored to make this a good project to learn about these things from the ground up. I sourced a decent wiring kit (CTS 500Ks, Switchcraft, Vitamin K .022, etc) that would essentially mod the wiring to what Peter Frampton used to run:

-pup selector functions like a normal LP (neck, neck/bridge, bridge)
-only a single tone knob for all three pups
-the middle pup is "always on", wired to what was the second tone pot that now acts as a volume for it.

Needless to say, I'm getting *nothing* out of the guitar now. Plugged in with the knobs all up, I get no response from the pups. When I max the tone knob, I get 60-cycle hum. That's it. So something's not right.

Can anyone see anything or point me in the right direction here?

Some basics:

-The three pups are each soldered to their respective pots; the wire is on the middle pin, and the ground is soldered to the back.
-One wire from the selector is wired to the left pin on the middle pup pot. The right pin is soldered to the back of the pot, and then grounded to the bridge ground.
-Another wire from the selector is wired to the third pin on the neck pup pot. The right pin is soldered to the back of the pot.
-The last wire is soldered to thethird pin on the bridge pup pot. The third pin is soldered to the pot itself again.
-There is a ground from the selecter also soldered to the neck pup pot where the bridge ground is soldered. (The back of that pot has, in total, the bridge ground, the ground from the middle pup pot, the ground form the selector, and the ground form the neck pup.)

Thanks for any help you have. I know this is a mess...

--->DJ

 

[GuitarDoc]

Re: The LP Frampton project - desperate help needed!

Welcome to the forum as an official poster.

Never cared much for the 3 pup wiring scheme of Gibson. Blueman has a very good solution which works great. You may want to PM him.

Why do you have 2 ground wires between the neck and middle vol pots (green and black)?

 

[DJ Catchem]

Re: The LP Frampton project - desperate help needed!

Welcome to the forum as an official poster.

Never cared much for the 3 pup wiring scheme of Gibson. Blueman has a very good solution which works great. You may want to PM him.

Why do you have 2 ground wires between the neck and middle vol pots (green and black)?

Thanks very much!

I wasn't crazy about the 3-pup scheme either, which is what drew me to this schematic. It's basically a normal LP with the middle pickup option.

Why do you have 2 ground wires between the neck and middle vol pots (green and black)?

Fantastic question. The kit had the braded black wires already soldered, and it basically looks like it grounds the four pots in sequence to each other. (tone->bridge->neck->mid) The extra green ground was labled as "connect this to bridge ground", so while it might be a little hard to see, it's actually soldered on that lead as it connects with the neck PUP pot.

Any thoughts on why I wouldn't get *any* response from the guitar? It's almost as if there are no connections between the jack and the rest of the electronics. I would think that if the jack was wired to the pots, and the pots were wired to the PUPs, the worst that could happen is that the selector would be doing weird stuff, but at least *something* would give me some sound.

Thanks again,

--->DJ

 

[hamerfan]

Re: The LP Frampton project - desperate help needed!

"Why do you have 2 ground wires between the neck and middle vol pots (green and black)?"
You dont need the green one. The black is enough!

I don't see a hot coming from the middle pot to the hot lug of the jack!

 

[DJ Catchem]

Re: The LP Frampton project - desperate help needed!

"Why do you have 2 ground wires between the neck and middle vol pots (green and black)?"
You dont need the green one. The black is enough!

I guess that stands to reason. Forgive my rudimentary wiring knowledge, but if the black wire ties the neck and mid pots together and the neck pot is grounded to the bridge lead, you're saying that the green is basically doing the same thing?

I don't see a hot coming from the middle pot to the hot lug of the jack!

The jack is grounded to the tone pot, and then attached to the tone pot lead. That's the only place that the jack is attached to the rest of the harness; I was under the assumption that this is because all three volume pots use the same tone pot. Is this incorrect?

Thanks very much!

--->DJ

 

[Funkfingers]

Re: The LP Frampton project - desperate help needed!

Looking at the top photo, the output cables to the jack socket both appear to connect firstly to the Master Tone pot. There is a capacitor to govern the cutoff frequency at which the tone control rolls off BUT...

...there appears to be no input cable connected to the tone pot. :gasp:

Nothing in. Nothing out.

 

[hamerfan]

Re: The LP Frampton project - desperate help needed!

The jack is grounded to the tone pot, and then attached to the tone pot lead. That's the only place that the jack is attached to the rest of the harness; I was under the assumption that this is because all three volume pots use the same tone pot. Is this incorrect?

Thanks very much!

--->DJ

The outputs of all pots have to got to the hot lug of the jack. Think of the sound of all pickups going thru all pots to the output jack ...... like water flow.

 

[DJ Catchem]

Re: The LP Frampton project - desperate help needed!

Looking at the top photo, the output cables to the jack socket both appear to connect firstly to the Master Tone pot. There is a capacitor to govern the cutoff frequency at which the tone control rolls off BUT...

...there appears to be no input cable connected to the tone pot. :gasp:

Nothing in. Nothing out.

There's a 'hot' lead from the input jack (the white wire) that is connected to the far left lead on the tone pot. The black lead (ground) from the jack is soldered to the back of the tone pot. The cap is soldered on one end to the back fo the tone pot, and on the other end bridging across the remaining two leads on the tone pot.

The only other wire attached to the tone pot, though, is the black ground going to the bridge pot. So if I'm understanding properly, there's essentially nothing other than a ground connecting the tone pot (and thus input jack) to the rest of the wiring.

Er...wow.

So, looking at the schematics, what I'm missing is a hot lead from the tone pot to the mid volume pot, which should in turn tie everything else together by way of the input selector? Or does there need to be something else going on in there?

Thanks,

--->DJ

 

[DJ Catchem]

Re: The LP Frampton project - desperate help needed!

The outputs of all pots have to got to the hot lug of the jack. Think of the sound of all pickups going thru all pots to the output jack ...... like water flow.

This makes a ton of sense, and I'm starting to feel like a total idiot the further I go here.

Since the middle pickup is wired in an "always on" configuration, do I need to tie anything else to the input jack other than the mid pot? I would think that the jack ---> mid pot ---> selector switch would then enable the rest of the pups based on switch position while leaving the mid always active. Or am I missing something?

Thanks so much, everyone!

--->DJ

 

[Funkfingers]

Re: The LP Frampton project - desperate help needed!

Just a minute. The Gibson Peter Frampton LP Custom guitar control circuit is not three vols, one tone. It is; B/N Vol + B/N Tone and Middle Vol + Middle Tone.

The bridge and neck PUs run through the selector switch and then to what is, effectively, a master volume, master tone control layout. (Like a Telecaster.)

The middle PU gets its own volume and tone controls. Its signal runs to the jack socket in parallel to the bridge/neck pair along a separate cable.

 

[DJ Catchem]

Re: The LP Frampton project - desperate help needed!

Just a minute. The Gibson Peter Frampton LP Custom guitar control circuit is not three vols, one tone. It is; B/N Vol + B/N Tone and Middle Vol + Middle Tone.

The bridge and neck PUs run through the selector switch and then to what is, effectively, a master tone, master tone control layout. (Like a Telecaster.)

The middle PU gets its own volume and tone controls. Its signal runs to the jack socket in parallel to the bridge/neck pair along a separate cable.

Hrm...this isn't quite that, then.

This wiring schematic is designed to basically make the guitar function exactly like a traditional two-pup LP, with the exception that all three pups utilize the same tone knob. From there, the mid pup is wired to be parallel to the other two, so that you can effectively control it with the mid volume pot; that way, you can add it to the neck pup, the bridge pup, or both depending on the selector position.

Does that change things?

--->DJ

 

[Funkfingers]

Re: The LP Frampton project - desperate help needed!

This wiring schematic is designed to basically make the guitar function exactly like a traditional two-pup LP, with the exception that all three pups utilize the same tone knob.

I do not know precisely what schematic diagram you are following. You appear to be replicating the circuit found in Epiphone Les Paul and SG Custom 3PU models.

The historically correct Gibson 3PU circuit is not the same. It requires a special selector switch and an out-of-phase middle pickup.

The blueman_335 circuit might be the solution.

The Frampton circuit is the one I would use but, of course, I am not you.

 

[DJ Catchem]

Re: The LP Frampton project - desperate help needed!

I do not know precisely what schematic diagram you are following. You appear to be replicating the circuit found in Epiphone Les Paul and SG Custom 3PU models.

The historically correct Gibson 3PU circuit is not the same. It requires a special selector switch and an out-of-phase middle pickup.

The blueman_335 circuit might be the solution.

The Frampton circuit is the one I would use but, of course, I am not you.

I'm all sorts of confused now.

I was essentially trying to get rid of the stock (epi) schematic, and move to this:

http://cgi.ebay.com/FRAMPTON-3-humb...453?pt=Guitar_Accessories&hash=item5889f5118d

--->DJ

 

[Funkfingers]

Re: The LP Frampton project - desperate help needed!

I was essentially trying to get rid of the stock (epi) schematic, and move to this:

http://cgi.ebay.com/FRAMPTON-3-humb...453?pt=Guitar_Accessories&hash=item5889f5118d

Did you buy the advertised kit or are you attempting to imitate it? Your control cavity photographs show rather more wires than should be necessary to make the Frampton circuit work.

Also, as I pointed out earlier, the Frampton circuit has TWO tone pots.

Upon re-reading the e-Bay trader's listing description in full, it becomes clear that he doesn't know what he is talking about. The auction item is a straightforward component upgrade for the average Epiphone LP or SG Custom 3PU models.

 

[DJ Catchem]

Re: The LP Frampton project - desperate help needed!

Did you buy the advertised kit or are you attempting to imitate it? Your control cavity photographs show rather more wires than should be necessary to make the Frampton circuit work.

Also, as I pointed out earlier, the Frampton circuit has TWO tone pots. If you look at the e-Bay trader's product photograph, one of the pots is clearly labelled MT (Middle Tone).

Yeah...this was the purchased kit. And it is a bit misleading there, as the pic shows a "MT" pot, but if you look at the actual description, it says:

"This circuit gives allows the bridge pickup, neck pickup, or both together, and, using a separate volume control for the middle pickup, allows it to be used in any combination with the neck and bridge or on it's own. The tone pot is a Master Tone for all 3 pickups."

I think the missing component here is the hot lead from the mid volume pot to the input jack. In theory, if I pulled the green "ground" off from the mid-to-neck pot and rewired it from the mid third pin to the hot pin on the input jack, that should do what I need, correct? Essentially:

-input jack to mid and tone pots
-selector to mid pot

Is that missing anything?

Thanks again,

--->DJ

 

[Funkfingers]

Re: The LP Frampton project - desperate help needed!

Yes, you need to send a signal into the Master Tone pot in order to get any sound out of your guitar.

I must have revised my previous posting while you were replying to it. The eBay trader's listing is an accurate description of what is in the kit. Calling it the Peter Frampton circuit is incorrect of him.

Both the output cable from selector switch and the output cable from the Middle PU volume need to be soldered to the same lug on the Tone pot.

 

[DJ Catchem]

Re: The LP Frampton project - desperate help needed!

Yes, you need to send a signal into the Master Tone pot in order to get any sound out of your guitar.

I must have revised my previous posting while you were replying to it. The eBay trader's listing is an accurate description of what is in the kit. Calling it the Peter Frampton circuit is incorrect of him.

Both the output cable from selector switch and the output cable from the Middle PU volume need to be soldered to the same lug on the Tone pot.

That makes perfect sense, now that you've laid it out in front of me. Thanks for the help!

Would it make a functional difference if I wired it like this:

-selector to third tone lug
-mid volume pot to third tone lug
-input hot to third tone lug

Or like this?:

-input hot to third tone lug
-input hot to mid volume pot
-input hot to selector

I did re-read your edit up there; it think it's correct that the seller is mis-using the "Frampton" tag, but it's not a stock replacement for the standard Epi 3-pup wiring. The stock witing uses the three-way selector with the following layout:

1. Neck
2. Neck/Mid
3. Bridge

So you only get the middle pup with the neck stock, and you can't get neck/bridge at all together. This seems better.

--->DJ

 

[Zhangliqun]

Re: The LP Frampton project - desperate help needed!

Whenever I've had 3-pickup Gibsons, I wired the middle pu to a push/pull pot and from there directly to the jack. Keep it simple and logical without disturbing the basic Gibson volume/tone/selector switch scheme that you're used to, if you like it that way, and I do. In my view the middle pu doesn't need either a volume or a tone.

 

[DJ Catchem]

Re: The LP Frampton project - desperate help needed!

Whenever I've had 3-pickup Gibsons, I wired the middle pu to a push/pull pot and from there directly to the jack. Keep it simple and logical without disturbing the basic Gibson volume/tone/selector switch scheme that you're used to, if you like it that way, and I do. In my view the middle pu doesn't need either a volume or a tone.

Eh...I do hear you, but again, I'm a bit of a hack,a nd I don't need the added functionality of a push/pull or the extra options. I basically just want a LP that can give me neck, bridge, or both. The mid on this is just a bonus.

Speaking of, all is well now! It works like a charm. I made the following change:

-Rewired the mid-to-selector wire straight to the input jack.
-Wired the outside lead on the mid volume pot to the outside lead on the tone pot.

Fired it up, and everything worked perfectly as expected! The mid pup is now totally independant of everything, and the other two pups work exactly like a traditional LP.

I did add an extra ground from the tone pot to the bridge ground after the fact. I found that when the tone pot was turned up to full with the other volume knobs in any combination, I was getting a *ton* og 60-cycle hum unless I was touching metal on the guitar. I opened it back up and checked the solders on the grounds, but it all seemed okay, so I just added moved the ground that was on the mid pot to the tone pot, and everything cleared right up. It's clean and quiet, and sounds wonderful.

Thanks very much for the help, Funk!

--->DJ

 

[Funkfingers]

Re: The LP Frampton project - desperate help needed!

Thanks very much for the help, Funk!

You are welcome but there are some other guys in this thread who also deserve credit. :cool2:

There is also an e-Bay guitar parts seller who deserves a swift kick up his derriere. Not only is he breaching a Gibson trademark. He is applying it incorrectly. :grumble: