80's-influenced Wiring Scheme on SEs

DK88DFW

I'm not a doctor, but I play one on TV.
Joined
Jul 28, 2016
Messages
28
Location
Fort Worth, Texas
Hi everyone, first post here. Been playing primarily PRS for 12 years. I've owned 6 different SEs throughout the years. I currently own a 2001 Cherry Santana SE, 2009 Tobacco Sunburst SE Singlecut Trem, 2011 ex-Antique White SE Singlecut (distressed and modded to match like my brother's rat-rod '81 Camaro), and a 2013 Royal Blue SE Singlecut Trem. My prior 2002 Tremonti SE and 2005 SE Soapbar II have had to find other homes over the years.

Anyway, enough of my life story. Due to the nature of the projects I've been doing musically lately, I've been looking to convert these guitars to a twist on the '80s Custom wiring: however, instead of a sweet switch I will simply have a SPST on/off switch in its place. Part of this is converting the single-conductor pickup leads to at least 3-conductor and reversing the polarity of the neck pickup. I also intend to replace the steel slugs in the pickup with Alnico V rods (like the old T and B pickups from the '85ish PRS models) for a better split sound. I hypothesize that this will give the humbuckers slightly more output and a bit brighter.

It's safe to assume that with rod magnets in the slug coils, and no tone control, this is going to be a very BRIGHT guitar, and I wanna bring it back down to earth, so I'm thinking of using a 250K pot for the volume. Would this sound the same as using two 500K pots full up for volume and tone? On paper it would be, but I just wanna know if I'm overlooking anything.
 
Last edited:
Welcome!!

Unfortunately, I see a lot of technical jargon which is simply flying RIGHT over my head!!

I suggest posting this over on the PTC section, where you might receive better input.

Welcome, again!
Kevin
 
You can start with 500k and add a resistor to tame the high end if it's too much. Or consider a 300k pot. 250k works, too. There are no real rules, just what sounds best for you and the guitar. It may take a little experimentation, but these are cheap parts.
 
That's what I was thinking. Some of the other things I planned on doing was modding the stock pickups so that they could be coil split, and be hum cancelling (by result of flipping the polarity of the neck pickup); but also replacing the steel slugs with Alnico V rods (like the original T and B pickups from the 80s) for a better split coil tone.

With no tone control I think I can safely assume this setup would be ridiculously bright. I guess my real question would be: would using a 250K volume pot with no tone sound the same as a 500K volume and 500K tone, both full up? On paper it would appear so, but in practice could be a different story.
 
Hey guys!
Would this sound the same as using two 500K pots for volume and tone? On paper it would be, but I just wanna know if I'm overlooking anything.
No, because the idea with a 500K volume pot, you have 500K Ohm between the hot signal and ground, but with a tone pot you have both the 500K resistance plus the capacitor. The cap changes which frequencies are directed to ground so it's not the same electrically as just having another 500K volume pot in the circuit. While any tone pot is directing an extremely small amount of high frequencies to ground, even all the way up at 10, it's not the same.

IMHO start with 500K and if it's too bright, swap in a 250K, assuming you're doing this work yourself? Takes just a few minutes and doesn't cost much.
 
No, because the idea with a 500K volume pot, you have 500K Ohm between the hot signal and ground, but with a tone pot you have both the 500K resistance plus the capacitor. The cap changes which frequencies are directed to ground so it's not the same electrically as just having another 500K volume pot in the circuit. While any tone pot is directing an extremely small amount of high frequencies to ground, even all the way up at 10, it's not the same.

IMHO start with 500K and if it's too bright, swap in a 250K, assuming you're doing this work yourself? Takes just a few minutes and doesn't cost much.

Ok, I get what you're saying. In that respect, what would effectively simulate a 500K volume and 500K tone, both on 10? I really don't want to drill holes into the guitars for extra pots and switches, simply because I don't want a cluttered layout, especially when I never use a tone control. It just sits there on 10, and I control tone via my hands or amplifier/effects.
 
Ok so the decision is made, I've ordered my parts. Here's what the control layout on these guitars will be (I used a pic of an '87 Custom from vintageprsguitars.com):

tumblr_obbjfqPeX81qjcfr5o1_540.jpg


I went with the 250K pot because it should offset the fact that 1) there is no tone control, and 2) the addition of rod magnets will inevitably brighten the humbuckers. If it doesn't work, I'll just use a 500K. I'll chronicle all this once I get everything in.
 
Just an update everyone: Finished the wiring mods to one of my PRSi last night. Rod magnets will arrive tomorrow. But so far, this is what I've got:

It is near impossible to find a reliable wiring diagram for a non-PRS rotary switch. The one I bought was from StewMac and the directions I saw for it had the wrong switching positions, basically swapping the inner coil positions with outer coils and vice versa. Thanks to a fella on the Seymour Duncan forum we got it all sorted out.

Converting the stock G&B pickups to 4-conductor was a piece of cake--in fact, far easier than I anticipated. Rewired them to Duncan color codes and went to town. They're hotter in this particular guitar than I suspected, measuring 9.6K in the neck and 10.3K in the bridge, which results in 4.8K and 5.2K split (a figure I also checked with my trusty multimeter)--a little weak but not too terrible.

The hardest part of the wiring was wiring up the rotary and getting it to fit. The StewMac rotary barely fits if you bend a couple tabs, even then I was fearing shorting out the connections on the shielding paint of the cavity. For wire I just used some leftover 4-conductor cable leads, that way I could even color code my wiring, and the thinner gauge wire wouldn't take up so much room. I then wrapped the housing of the switch with masking tape to separate the tabs and solder joints from the cavity's shielding. The 250K pot wasn't terrible but did rob me of some bite from the pickups, so I reused the stock 500K pot in the guitar.

Wiring the on/off switch was a piece of cake, because it's not the first guitar I've done that to. I bought a simple DPDT switch while at Fry's for $3 and used that. I installed it where the tone control/sweet switch would normally go, and of course opted for no tone knob at all.

It sounds great! Definitely getting some cool tones from the axe, especially in positions 2 and 4, however I won't make my final judgment until I install the A5 rods when they come in (which should be, according to USPS, tomorrow). I've already checked, and the ones I ordered should be a perfect fit, and might take 10 minutes to install. I may include some sound clips once I'm all done, and some pictures of the next PRS I work on. I'll keep everyone posted!!
 
Right on, man! I want to see pics of this one. :) Here I thought I was the only one who saw any potential in the G&B pickups with some mods (split wire, alternate magnets), but you've taken it a step further.
 
Right on, man! I want to see pics of this one. :) Here I thought I was the only one who saw any potential in the G&B pickups with some mods (split wire, alternate magnets), but you've taken it a step further.

Your posts inspired me in part to split the coils in the first place. I personally love the G&B pickups in my PRSi. Some of the best OEM pickups in that price range of guitar outside of true Duncans (not the Designed variety).

As for magnets, I have yet to change the bar magnets. I'm currently still waiting on the rods to arrive from Tone Kraft. I just ordered .187" vintage bevel .531" tall Alnico 5 rod magnets, 6 magnetized North up and 6 magnetized South up, to match to polarities of the pickups. These should drop right in place of the slugs, except maybe sit just barely proud of the bobbin (which I'm totally OK with). We'll see what this does to the tone, predicting slightly more output with more bite. I may go with A2 bar magnets if too bright.

I was unable to provide pics of the process, but when I do the slug to magnet mod I'll take pics for that. I'm doing this to one of my other SE Singlecuts this week, and will take pictures for sure.
 
So the magnets arrived today!!!

This is the first guitar for mods, a 2011 Primer Grey (formerly Antique White) SE Singlecut. Bought it for $200 at a Guitar Center here in Texas with a cracked neck. Three weeks after I bought the guitar it fell off its stand and the neck split cleanly from the body. It was easy enough to reset the neck and move on, but the break left a nasty scar. I planned on refinishing it, but a mishap during the final primer coat damaged the headstock (I repaired this too) so I said, "F--- it," and left it be. It now matches my brother's project 1981 Camaro. Still plays quite nicely. I replaced the stock tuners with Gotoh oval button tuners after one of the stock buttons broke off during the fall. Bridge was also replaced with a Gotoh 510UB, which ain't too shabby.
tumblr_obobljCHXg1qjcfr5o1_540.jpg


Some tips I can offer while wiring up this setup:
1) If you bought the PRS rotary, then you probably know what to do. But if you bought an aftermarket switch, DON'T use the diagrams offered by StewMac, or most of what you see online. They don't work like a PRS rotary is supposed to.
Use this diagram provided by Seymour Duncan forumite BriGuy1968, who was so kind to draw this up just for me:
2fbc452fc78a0a8d2baba93fdd71807b_zpsisysl7l4.jpeg

I opted to not use a tone control, instead wiring in a DPDT on-off switch in its place. This is easy to do, if you need a schematic they're all over the internet.

2) Make sure the wiring of your pickups are correct. Most of the stock G&B pickups on the SEs only have 1-conductor cables, with the hot going to the screw (outer) coil and the slug (inner) coil going to ground. You MUST have a dedicated conductor for the slug coil. I went ahead and used standard 4-conductor wire and wired to Duncan colors:

Slug Coil
Series Link
Screw Coil

3) G&B pickups are polarized so that the screw coil is oriented South and the slug coil is North, on both pickups. For this wiring you must reverse the magnet in one of the pickups (I flipped the bridge magnet). Otherwise positions 2-4 will not be humcanceling.

4) If you chose to buy the PRS rotary, which I may do in the future with my other SEs, don't worry about this. Otherwise, make sure you wrap the aftermarket rotary switch with electrical tape to avoid shorting out the connections on the shielding paint inside the cavity. It is a VERY tight fit, and you will have to bend a couple tabs to make it work.

That should get you going on the wiring aspect.


The next part I want to talk about is swapping the slugs in for rod magnets. Now, most of you probably have no interest in doing this. I did it out of curiosity and liked the results. It's not a night-and-day difference in the least but it's something you should still hear. For me, it actually refined the tone a bit. I feel like it gave me more crisp highs and more bite, yet smoothed out the tone at the same time. It's more articulate to me this way.

So the first thing you should do is get something to push the slugs out. I used a precision screwdriver and a small Allen wrench. It helps to use a soft surface with a lot of give so you can really bear down and put some pressure on the slugs to force them out. It will take some effort because the wax potting is effectively working like glue here. I did this on my bed after replacing the leads, so the pickups were still out of the guitar, and I could do this without damaging the guitar or the pickup. I then put the slugs back in to reassemble the guitar and test the wiring, before swapping them out and showing you. If you have the stock G&B pickups, GREAT, because you can access the slugs with the baseplate still attached and without disassembly. A lot of pickups don't have these holes in their baseplates, and if that's the boat you're in, then your job just got harder.

Since I put the slugs back in after I broke them loose, I have to take the pickup out again. Since the wax has been broken around the slugs, all I have to do is gently push on the slug to get it to come out the top.
tumblr_obobljCHXg1qjcfr5o2_540.jpg


Once that's done, your pickup should look like this:
tumblr_obobljCHXg1qjcfr5o3_540.jpg


Now, the slugs measured .187" diameter x .500" length. You need to find a rod magnet with dimensions similar to this. I bought mine from Tone Kraft. The closest I could find was a vintage bevel Alnico V rod that was the same diameter and .531" in length. They'll even magnetize them for you in the orientation of your choosing. This is important, in case you want the bevel facing up. I ordered 12 oriented North up, and 12 South up.

When installing these, it is imperative that whatever polarity that coil is matches which pole is facing up on the magnet when you push it in the bobbin. For example, if the screw coil is North and the slug coil is South, then South should face up on these rod magnets. To ensure this, a polarity tester is highly recommended. Then, it's really as simple as pushing them into the holes. They'll stick up above the bobbin about the diameter of a G or D string, but no more than that.

Here is the finished look of the rod magnets in the humbucker. There are still bits of wax on top of the bobbin here but 1) that shouldn't hurt anything, and 2) it's easy enough to clean up:
tumblr_obobljCHXg1qjcfr5o4_540.jpg


OH WAIT...well how does it sound??

I recorded a clip of the finished product. The before clip got lost in the shuffle somewhere, but this should effectively demonstrate the big picture. In this I go from clean to dirty, and cycle through all the pickup positions, starting with the bridge pickup and working my way to the neck, in order. Note the significant volume drop in positions 2 and 4. Click the link below.

https://soundcloud.com/david-h-kennedy-782434002/prs-rod-magnet-mod-demo

THE VERDICT:
I think this is a better alternative to the standard SE coil split. I'm not too thrilled by the volume drop in the split positions, but that is the nature of the beast and there are ways around it (i.e. using a clean boost in conjunction with it). Overall, the versatility of this setup is ridiculous in an SE, and I plan on doing this again to my other guitars.

That said, I feel the neck pickup is too bassy for me, and am wondering if switching to an Alnico II bar magnet would help lower the bass and bring out the mids in this position?
 
Last edited:
This morning I went ahead and soldered a 560K resistor between the input lug and ground of my volume pot. The stock 500K pot (which actually measured at 440K) was just too bright, and I felt like the guitar needed to "see" the additional load of a tone pot. I went with 560K, because using the total resistance formula: 440 x 560 / 440 + 560 = 246.4K ohms, or within 1.5% of the spec of 250K total resistance. Much better now, and NOT the same as just going with a 250K pot. The 250K had sort of a cocked wah thing going with not nearly enough attack on the strings.
 
So the magnets arrived today!!!

This is the first guitar for mods, a 2011 Primer Grey (formerly Antique White) SE Singlecut. Bought it for $200 at a Guitar Center here in Texas with a cracked neck. Three weeks after I bought the guitar it fell off its stand and the neck split cleanly from the body. It was easy enough to reset the neck and move on, but the break left a nasty scar. I planned on refinishing it, but a mishap during the final primer coat damaged the headstock (I repaired this too) so I said, "F--- it," and left it be. It now matches my brother's project 1981 Camaro. Still plays quite nicely. I replaced the stock tuners with Gotoh oval button tuners after one of the stock buttons broke off during the fall. Bridge was also replaced with a Gotoh 510UB, which ain't too shabby.
tumblr_obobljCHXg1qjcfr5o1_540.jpg


Some tips I can offer while wiring up this setup:
1) If you bought the PRS rotary, then you probably know what to do. But if you bought an aftermarket switch, DON'T use the diagrams offered by StewMac, or most of what you see online. They don't work like a PRS rotary is supposed to.
Use this diagram provided by Seymour Duncan forumite BriGuy1968, who was so kind to draw this up just for me:
2fbc452fc78a0a8d2baba93fdd71807b_zpsisysl7l4.jpeg

I opted to not use a tone control, instead wiring in a DPDT on-off switch in its place. This is easy to do, if you need a schematic they're all over the internet.

2) Make sure the wiring of your pickups are correct. Most of the stock G&B pickups on the SEs only have 1-conductor cables, with the hot going to the screw (outer) coil and the slug (inner) coil going to ground. You MUST have a dedicated conductor for the slug coil. I went ahead and used standard 4-conductor wire and wired to Duncan colors:

Slug Coil
Series Link
Screw Coil

3) G&B pickups are polarized so that the screw coil is oriented South and the slug coil is North, on both pickups. For this wiring you must reverse the magnet in one of the pickups (I flipped the bridge magnet). Otherwise positions 2-4 will not be humcanceling.

4) If you chose to buy the PRS rotary, which I may do in the future with my other SEs, don't worry about this. Otherwise, make sure you wrap the aftermarket rotary switch with electrical tape to avoid shorting out the connections on the shielding paint inside the cavity. It is a VERY tight fit, and you will have to bend a couple tabs to make it work.

That should get you going on the wiring aspect.


The next part I want to talk about is swapping the slugs in for rod magnets. Now, most of you probably have no interest in doing this. I did it out of curiosity and liked the results. It's not a night-and-day difference in the least but it's something you should still hear. For me, it actually refined the tone a bit. I feel like it gave me more crisp highs and more bite, yet smoothed out the tone at the same time. It's more articulate to me this way.

So the first thing you should do is get something to push the slugs out. I used a precision screwdriver and a small Allen wrench. It helps to use a soft surface with a lot of give so you can really bear down and put some pressure on the slugs to force them out. It will take some effort because the wax potting is effectively working like glue here. I did this on my bed after replacing the leads, so the pickups were still out of the guitar, and I could do this without damaging the guitar or the pickup. I then put the slugs back in to reassemble the guitar and test the wiring, before swapping them out and showing you. If you have the stock G&B pickups, GREAT, because you can access the slugs with the baseplate still attached and without disassembly. A lot of pickups don't have these holes in their baseplates, and if that's the boat you're in, then your job just got harder.

Since I put the slugs back in after I broke them loose, I have to take the pickup out again. Since the wax has been broken around the slugs, all I have to do is gently push on the slug to get it to come out the top.
tumblr_obobljCHXg1qjcfr5o2_540.jpg


Once that's done, your pickup should look like this:
tumblr_obobljCHXg1qjcfr5o3_540.jpg


Now, the slugs measured .187" diameter x .500" length. You need to find a rod magnet with dimensions similar to this. I bought mine from Tone Kraft. The closest I could find was a vintage bevel Alnico V rod that was the same diameter and .531" in length. They'll even magnetize them for you in the orientation of your choosing. This is important, in case you want the bevel facing up. I ordered 12 oriented North up, and 12 South up.

When installing these, it is imperative that whatever polarity that coil is matches which pole is facing up on the magnet when you push it in the bobbin. For example, if the screw coil is North and the slug coil is South, then South should face up on these rod magnets. To ensure this, a polarity tester is highly recommended. Then, it's really as simple as pushing them into the holes. They'll stick up above the bobbin about the diameter of a G or D string, but no more than that.

Here is the finished look of the rod magnets in the humbucker. There are still bits of wax on top of the bobbin here but 1) that shouldn't hurt anything, and 2) it's easy enough to clean up:
tumblr_obobljCHXg1qjcfr5o4_540.jpg


OH WAIT...well how does it sound??

I recorded a clip of the finished product. The before clip got lost in the shuffle somewhere, but this should effectively demonstrate the big picture. In this I go from clean to dirty, and cycle through all the pickup positions, starting with the bridge pickup and working my way to the neck, in order. Note the significant volume drop in positions 2 and 4. Click the link below.

https://soundcloud.com/david-h-kennedy-782434002/prs-rod-magnet-mod-demo

THE VERDICT:
I think this is a better alternative to the standard SE coil split. I'm not too thrilled by the volume drop in the split positions, but that is the nature of the beast and there are ways around it (i.e. using a clean boost in conjunction with it). Overall, the versatility of this setup is ridiculous in an SE, and I plan on doing this again to my other guitars.

That said, I feel the neck pickup is too bassy for me, and am wondering if switching to an Alnico II bar magnet would help lower the bass and bring out the mids in this position?


Hello! Nice mods. How do you like this Gotoh 510ub bridge? By the measures, i think it´s taller than the stock PRS SE (about 3mm). Can you get a nice string action?
 
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