G&L F100 Pickup Wiring Question

[themadflyentist]

Hello All,

I posted this question in the G&L Forums and was referred here for more expertise. I realize this may not directly related to Seymour Duncan products, I hope that's okay.

I am in the process of pseudo-restoring an early 80's G&L F100 with active/passive electronics. The original pickups were switchable between active and passive, and they had three wires coming off each pickup. My guitar had a pre-amp wired into the circuitry as well, and here is the schematic: http://www.guitarsbyleo.com/GALLERY2/main.php?g2_itemId=3075

The only difference between that schematic and my setup is that on mine there is a small capacitor wired between the "bridge pickup" pole of switch one (S1) and the top left pole of S2 (unused in the schematic). I am unsure of the ramifications of this capacitor.

I only have one of the original pickups and it is badly damaged. OEM replacements are several hundred dollars, and I simply do not have that to spend right now. I did, however, find a relatively nice set of mini-humbuckers that fit in the slots perfectly. The only issue is that the new pickups have only two wires (ground and hot, I assume - one is insulated and one is simply braided). I realize that by using a non-switching pickup I will lose some functionality on the guitar. I am fine with this, I just want to ensure that it's even possible to use these pickups with the electronics I have.

My questions are:

* Can I simply wire the humbuckers to S1 (as per schematic) and then ground them to the VR1 pot (also per schematic)? I would cap/clip the single-coil pickup leads if I did this.

* Does the capacitor wired from S1 likely have any major ramifications? I would need to solder to the pole of S1 where the capacitor is currently connected in order to wire it how the schematic says to.

* Am I missing anything serious? Can I fry anything if these pickups are somehow not compatible?

Thank you so much in advance for any advice.

 

[Mincer]

Re: G&L F100 Pickup Wiring Question

Welcome to the forum!

We welcome all sorts of pickup talk here. I am sure we have some G&L fans that understand more about those pickups than I do. Stick around, and be patient.

 

[Artie]

Re: G&L F100 Pickup Wiring Question

That's a heck of a wiring diagram. I'm trying to make heads or tails out of it. Do you know the function of S2 and S3? S2 appears to be related to splitting, but not sure, yet, why it's an on-on-on switch. Also, VR1, 2, and 3. VR1 looks like the volume control and VR2 looks like the tone, but VR3 is a little weird.

I also notice that in some of those pics, S3 has 6 terminals, and in others, it has 9.

Edit: Ok, I see that VR3 is the "bass" control. VR2 is "treble".

Edit 2: The 4PDT switch is HB'er in one position, then the split wire is connected to ground through a cap, in the middle position, and then split wire straight to ground in the 3rd position. Interesting. The DPDT switch is the active/passive switch.

Still trying to figure out what your "extra" cap does.

 

[Silence Kid]

Re: G&L F100 Pickup Wiring Question

S2 is full humbucker, split, and bass boost/split.

S3 is some combination of high impedance, low imp. and low imp. with treble boost.

VR1 is volume, VR2 tone, VR3 is a reverse tapered bass roll-off that is part of the PTB system.

 

[Artie]

Re: G&L F100 Pickup Wiring Question

Ah. Thanks. That helps decipher everything else.

 

[beaubrummels]

Re: G&L F100 Pickup Wiring Question

My first touring guitar was an F-100. I don’t remember it being active/passive, at least I’d forgotten about changing any batteries.

 

[Silence Kid]

Re: G&L F100 Pickup Wiring Question

Passive and active models were made; mine is passive. Passive switches were just two two-ways: a split, and an out of phase. Pickups themselves are the same between both active and passive models, it's just the preamp, battery and switches that are different. I have never played an active model, but like my passive guitar enough to have some research under my belt

Also- the pickups are actually wired for a partial split which keeps some of the opposite coil alive for hum canceling.

Yet more random obscure trivia about these guitars: Earlier specimens had no treble pot active on the bridge pickup, later (post '82?) the bridge gets wired to the treble control which cuts down on some brightness.