Post by UnklMickey on Feb 6, 2006 18:21:51 GMT -5
_______________________THE BIG UGLY ___________version 2.0 - © 05FEB06
When I first began this design, I considered some of the desirable traits of “good design”:
- 1 - No coils shunted.
- 2 - No dead spots.
- 3 - No unused coils “hanging from hot”.
- 4 - All combinations hum-canceling.
- 5 - Intuitive layout
2 single coils, while posing little challenge, also posed few combination possibilities.
3 single coils, proved to be limited in the possibilities for hum-cancelling combinations.
4 single coils, or S-S-H, or 2 HBs, seemed to be the right choice in terms of flexibility and a natural affinity for hum-canceling combinations.
While drawn as a 2HB design, it will work well in a S-S-H, H-S-S, or 4-single configuration. The requirement is to have 2 “normal” coils, and 2 RWRP.
I set out to design a switching network using 1, 5-way superswitch and 2, DPDT switches.
I reasoned, this would lend itself to a clean, uncluttered look.
The desire was to create as many usable hum-canceling combinations as possible.
To facilitate including an “all-on” (position 3) position, it was necessary to “stack” (series-connected) coils in pairs. This made it impossible to use those pairs in parallel with themselves other. But it also made it possible to implement a novel scheme for doing Out-of-Phase, while maintaining hum-cancelling. I have labeled it in quotes, as it not a pure phase-reversal. This scheme involves exchanging the coils in the bridge “stack”. This will cause a slight difference in the sound from a simple inversion of the same bridge coil, but allows for hum-canceling.
Version 1 of this circuit, came close to meeting these goals, but did, in some cases, have coils “hanging from hot”. It also did not provide a “single coil” selection.
Version 2 (seen below) will in one case (position 4), have BOTH coils with a phase reversal from the normal, while maintaining their relative phase relationship. This results in a situation that I believe will sound the same as a “normal” in phase situation. As a result, there are NEVER unused coils hanging from hot. The worst case, in positions 2 and 4, the unused neck coil will hang from the mid-point in series mode.
The 5-way selects which coils will be used. Series or parallel is determined by a DPDT in this case, a push-pull switch on the volume control (pull for SERIES). The “Phase” switch is a push-pull on the tone control.
The sequence on the 5-way, and the location and direction of the 2 DPDTs can be readily changed. But, their basic tasks remain the same.
FOR Single - Single - Humbucker:
| push-pull settings → ______________ ↓ 5-way position | Parallel ....▄...▄...... | Parallel OoP ....▄...█...... | Series ....█...▄...... | Series OoP ....█...█...... |
| 1 | Neck | Neck | Neck * Middle | Neck * Middle |
| 2 | Neck and Bridge (N) Parallel | Neck and Bridge (S) Parallel, Oop | Neck and Bridge (N) Series | Neck and Bridge (S) Series, OoP |
| 3 | (Neck * Middle) and Bridge HB Parallel | (Neck * Middle) and Bridge HB Parallel, OoP | (Neck * Middle) and Bridge HB Series | (Neck * Middle) and Bridge HB Series, OoP |
| 4 | Middle and Bridge (S) Parallel | Middle and Bridge (N) Parallel, OoP | Middle and Bridge (S) Series | Middle and Bridge (N) Series, OoP |
| 5 | Bridge (north only) | Bridge (south only) | Bridge (ser) HB | Bridge (ser) HB |
FOR 2 Humbuckers:
| push-pull settings → ______________ ↓ 5-way position | Parallel ....▄...▄...... | Parallel OoP ....▄...█...... | Series ....█...▄...... | Series OoP ....█...█...... |
| 1 | Neck (south only) | Neck (south only) | Neck (ser) HB | Neck (ser) HB |
| 2 | Outer coils Parallel | South coils Parallel, Oop | Outer coils Series | South coils Series, OoP |
| 3 | Both (ser) HB Parallel | Both (ser) HB Parallel, OoP | Both (ser) HB Series | Both (ser) HB Series, OoP |
| 4 | Inner coils Parallel | North coils Parallel, OoP | Inner coils Series | North coils Series, OoP |
| 5 | Bridge (north only) | Bridge (south only) | Bridge (ser) HB | Bridge (ser) HB |
In positions 2 and 4, one coil from each HB is used. In normal mode they are: outer coils (position 2), and inner coils (position 4). In reverse “Phase” they are both South coils (position 2), and both north coils (position 4)
In position 3, both HBs are selected. Each HB is locally in series. The 2 HBs are in system parallel (normal) or system series, as determined by the series / parallel switch. The “phase” switch inverts the phase of the bridge HB in relation to the neck HB.
In position 1, since the HB is already pre-wired in series, the only parallel combination would be Out-of-Phase. Since that has a relatively weak output and would also not be hum-canceling, I decided against this in favor of having the south coil only when the series / parallel switch is in PARALLEL. In SERIES mode it is a normal series HB. The “phase” switch has no effect. This is accomplished by the “blue wire” option. In the single coil mode (parallel switch), 2 rules are broken. It is not hum-cancelling (obvious, as there is no second coil to cancel hum) and the usused coil is shunted.
In position 5, we see a similar situation with the bridge HB. In PARALLEL normal, the bridge north is selected. In PARALLEL OoP, the bridge south is selected. In SERIES normal, the normal series HB is selected. In SERIES OoP, the phase is inverted on the entire HB. This should for all intents and purposes sound the same as SERIES normal.
A “BLAST” button has been added as well. To use reduce the volume to a lower level on the guitar volume control. While the button is pressed, the volume will increase to full. To omit this switch, simply connect the right hand lug of the volume pot directly to the star ground.
The 17 sounds that are available from the 20 possible combinations of the 5-way and 2 DPDTs are displayed on the following “Connectivity Map”.
The relative spacing between the coils will have a large effect on how different the sounds will be, especially in positions 2 and 4. In an S-S-H configuration, 2 will sound more “Tele-ish” and 4 will sound more “Strat-ish”.
I would expect be able to describe the use of the DPDTs as follows:
Parallel:_____________“normal”
Parallel OoP:_________“thin”
Series:______________“dark”
Series OoP:__________“hollow”
But, this is just pure speculation at this point.
I would caution anyone intending to use this design; at this point this circuit is purely theoretical.
The early versions have been proofread by John Hewitt.
EDIT: 16 FEB 06 JohnH has proofread it and jimplaysguitar has built it. i've asked him to wait until after he has lived with it a while before commenting on it.
Acknowledgements:
I would like to thank RandomHero and all the GuitarNutZ for providing an environment that is conducive, to the kind of thinking that made this endeavor possible.
I would like to thank Fenleo for the concept of mapping individual switch selections, and the template from an earlier analysis, that I modified and added pieces created by Almostawake and Jimplaysguitar to make the framework for these drawings.
I would like to thank Runewalker for being a such great friend to chat with, for the encouragement he has given me, and thanks in advance, as I suspect he will be one of the first to build, test, and evaluate this circuit.
And finally, I would like to thank John Hewitt (JohnH), for his repeated proofreading of many of my designs. His work in this area has made me look a little less scattered in public, than I otherwise would have looked.
Unklmickey © 05FEB06
SAGWBLT
(Edited by JohnH 20/01/10 to restore diagrams)
Making the best of cheap guitars is a good option since I can't afford expensive real Fenders.
