04 December 2012

Wiring Diagram: Hermetico's LP Exchanger mod 2

Classification

Guitar Modded

Gibson Les Paul


Description
  • HH Pickup layout (4 conductors)
  • 1 Swiftcraft 3-way toggle switch
  • 2 volume pots with pull/push
  • 2 tone pots with pull/push

Difficulty Level

Hard

Features

  • Provides standard LP combos, plus a high variety of other combinations.
  • Independent volume and tone for each pickup.
  • Enhanced version of Jimmy Page's wiring design
Wiring Diagram

Click on the diagram for a full sized view.



Comments

Jimmy Page's wiring mod achieves a lot of different combinations but, in my honest opinion, it does it in a way that isn't easy to recall and, some of the combinations produce just silence (the guitar shuts up).
The Exchanger 2 mod is my own take around the Jimmy Page's mod but, making controls easier to map in your mind so, you will be able to easily achieve exactly the combo you were looking for.
 
Each Tone pot splits its corresponding pickup.
Neck Volume puts Neck pickup out-of-phase (changes polarity).
Bridge Volume puts both pickups in series, overwriting the 3 positions of the 3-way (instant booster).
 
But there are some tricks hidden under this design.
Default, NT splits the neck pickup to outer coil but, if you have also BT up, selected coil is inner, instead.
Default, BT splits the bridge pickup to inner coil but, if you have also NT up, selected coil is outer, instead.
Also, the NV (neck volume), when changing the polarity of neck pickup (OOP) is reverting which coil is split by the NT pull/push.
 
In this way, we are achieving one more unique combo than in JP's wiring mod and, the best of all: there is no combo that can accidentally shut up the guitar!.
 
Click on this picture to see a full size of the list of combos:
 
 
In red, unique combos (that appear at least once in that list).
Notice that when the serial switch is up (BV = Bridge Volume), the three positions of the 3-way toggle switch have exactly the same combination. Once you push down BV, whatever the combo that was before in the current position comes back.
By example, imagine we had BV = down, NV = up, NT = up and BT = down and we had selected Rhythm position, we should have selected Neck Inner Coil but, once BV is up, we are having Bridge humbucker in series with Neck Inner Coil Out-of-Phase.
Imagine that, while in series, we change to Treble position. There is no change in the sound, since we are getting the same combo but, once we push down BV, we are getting Bridge Humbucker, instead.
 
As in the case of JP's wiring, volume controls are independent and allow you to mix both humbuckers at your taste but, when both pickups are in series (BV = up), both controls are also in series so, rolling off a bit  one will also reduce the overall volume and, totally rolling off one we will shut up the guitar. In this case, the neck volume acts as some kind of master volume.
 
In the middle position (and in parallel, BV = down), you will achieve different nuances by mixing each pickup at different levels, since some frequencies will be reinforced while others will be dimmed.
Also, when in middle position and out-of-phase (NV = up), the different volume levels for each pickup, will give you different textures of the out-of-phase sound (Peter Green's mod), some are edgier, some are more subtle.
Just experiment with all this.

24 comments:

  1. working on this mod right now. having trouble with the bridge pickup though. with all knobs down as normal the bridge is split. I've triple checked my connections. maybe a fresh look tomorrow will reveal my mistake.

    ReplyDelete
    Replies
    1. What I can certify is that this mod works flawless. I've got it in my LP-clone guitar, for several years.

      Delete
  2. If bridge pickup is working full when the bridge tone pull/push is up then, reasons can be two:

    1) your pull/pushes works in a reversed mode so, when they are pushed, the upper lugs enter in contact with center lugs, instead of being the lower lugs
    2) you missurdestood the diagram and reversed lower and upper lugs in this pull/push. Check also other pull/pushes, then.

    You must see diagrams as if components were already mounted in their holes/pickguard. So, the pull/push lugs closer to the pot's lugs are the "upper" lugs of the pull/push if you stand it facing their lugs and with the shaft pointing to ceil. And those, farer from pot's lugs are the "lower" lugs of the p/p. See that tone pots are reversed in the diagram and, this can lead you to some confusion.

    ReplyDelete
  3. Wonderful job, man.

    I'm new to building guitars and I was looking for a diagram for a Les Paul in a Jimmy Page style. I will try to develop The Exchanger MOD 2, but I must confess that I got a bit confused with the pickups wires color. Can you bring some light?

    I'm also thinking in using .022 mF PIO capacitors. What is your opinion?

    Thank you much.

    ReplyDelete
    Replies
    1. Color wires of pickups corresponds to Seymour Duncan ones. White color is being represented in light blue, for readibility.
      About using 0.022 uF PIO caps; I don't see any issue. I like more the amount of high end that rolls off a 0.047 uF cap but, that's my particular taste.

      Delete
  4. Thank you for the information.

    Recently I watched this tip from StewMac (http://www.youtube.com/watch?feature=player_embedded&v=e0SLdOWvz3c) and I got myself thinking if I could use it with your diagram above. Do you think it is feasible and it will work properly?

    Thank you again.

    ReplyDelete
    Replies
    1. What you found there is what is commonly named a "treble bleed mod", one of the three. Please, look to my DIY Wiring Page and search for Treble Bleed mod.
      It's compatible with any wiring but, take into account the following: my design includes the '50s tone mod that gives some bright to humbuckers and rolls off trebles in a very natural way when rolling off the volume.
      You can always try it as it is and, if you still think you need the treble bleed, go for it. Nothing wrong

      Delete
  5. thank to your great wiring, i had applied this on my LP.
    but there's one i'm wondering since i use this mod, on normal condition (no pulling pot, all PU switched on) Volume Controls (N&B) can't be reduced till zero (pot on zero position but still produce sound).
    Is it normal or i had a wrong wiring.
    Thank you for your response.

    ReplyDelete
    Replies
    1. This is a known issue or drawback, related to independent volumes.
      For certain guitars, it happens that there is some bleed from pickups, even with pots at zero.
      Maybe, it's something related to pots themselves (honestly, dunno).
      I have not such an issue in my axe but, it doesn't mean that you wired it wrongly. It's a knows side effect that takes place, some times.
      But it should deliver very very low ouput in that case, otherwise, some ground could be bad (cold solder or similar).

      Delete
  6. Thanks for sharing!
    Does one of the pick-ups need to be magnet flipped?

    ReplyDelete
    Replies
    1. You're welcome!.
      Absolutely not. Otherwise, you would be in "Peter Green's mod" in middle position by default.

      Delete
  7. Dear Hermetico,

    I have built your LP-Exchanger mod2, and I have the issue which is reported by aL_saTyr (November 16, 2013 at 2:48:00 AM GMT+1).

    It is very annoying, I would like to extinguish it.

    Please tell me more about your experiences with this issue, if you have. And plaese, let me know what kind of humbackers, capacitors, and potentiometers do you use, to avoid the issue.

    Thank you for your help.
    Viktor

    ReplyDelete
    Replies
    1. Best way to get rid off this issue is to go for modern wiring (dependent volumes).
      Also, DON'T USE TREBLE BLEED MODS with this wiring !!!
      It will not work properly.

      Delete
  8. Hi Hermetico,

    You've done a great job with this LP-Exchange wiring, and I can't wait to give it a try.

    I have a question about it, after studying the diagram a bit, I don't understand how can the BT pot split the bridge when it's up if there is no way the two cables from the pup connect to ground, can you clarify this to me?

    Cheers

    ReplyDelete
  9. Do you typically solder the ground wires to the bottom of the pots? I worry about burning them out. I would just connect the ground lugs to a central ground, but the neck volume pot's ground lug isn't directly grounded in this diagram.

    Thanks.

    ReplyDelete
  10. I have the same issue as Brad. With the BT down the coil is split. The wiring is exactly as drawn here. Is there a fix for this?

    ReplyDelete
    Replies
    1. I have the some issue. BT down splits the bridge coil, up is normal humbucker.

      Delete
  11. There may be an error in the provided diagram causing the bridge coil to be split when BT is pushed down.

    I resolved the issue of "BT splits coil when in down position" by moving one wire on BT pot switch. The wire I moved is indicated in dark blue on the original schematic.

    On the schematic the dark blue wire is connected to the left DOWN LEFT pin of BT Pot/Switch. I moved it to the UP LEFT pin of the BT pot/switch. It resolved the issue. Hope it helps somebody!

    By the way, Thank you Hermetico for a great mod which now works as designed!

    ReplyDelete
  12. HermeticoGuitar - Do you agree with Jacek and the wiring change?

    ReplyDelete
  13. One of the blue connections to the BT pot/switch is incorrect in the diagram, as stated above it should be nearest to the pot so it is only enabled when in the 'Up' position. How the diagram is currently drawn when in the default (all down) position the bridge red/white wires would be routed through the NT switch, then the NV pot connection to the output switch. This would short the the north coil (black & white as per SD wiring) so only the South coil (red/green) is active. I hope this information helps.

    ReplyDelete
  14. I wired this thing to a T, including switching the BT blue wire. When I pull the BV it sounds like my tone control is at 0, definitely not in series. When I'm on the bridge pickup everything in all positions (out or in) sounds like my tone is at 0 as well. Any ideas?

    ReplyDelete
    Replies
    1. I don't see why you would be losing all high frequencies for the bridge pickup or in the series option (BV out) unless there is a wiring error somewhere in your setup. Are you sure the connections of the bridge volume are correct to the bridge tone pot? One simple test would be to disconnect the cap to the bridge volume pot, as this will take the bridge tone control out of the circuit completely which will help you to isolate the problem.

      Tom

      Delete

Please, feel free to add your comments.