Post by reTrEaD on Dec 6, 2016 11:26:33 GMT -5
It's December so it's not too soon to say: Merry Christmas, GuitarNutz!
The jolly round guy with the white beard isn't the only one with a sack full of presents.
I have three I'll be serving up, one thread each.
I've elected to put this in the Design Modules subforum because this is an exercise in meshing two modules together. Coil selection and a S/P switch. I previously covered the SP switch in this thread: Shifting Gears: The Series/Parallel module
All three installments will feature the same overall architecture:
- A 4P5T superswitch as the pickup selector
- A DPDT switch (perhaps a push-pull) as global Series/Parallel switch.
The difference between versions is how the four poles of the superswitch are assigned.
These structures are all intended for use with a master volume and master tone control,
(although two volume controls will be possible in some cases)
Since a Strat has three holes for potentiometers, I've included an optional shunt-fader to occupy one of the holes.
These drawings are more schematic than wiring diagram.
The intent is to provide a highly visual perspective of how the four poles serve us.
Wiring of each switch position is omitted for two reasons.
1 - elimination of clutter.
2 - there are far more combinations possible than the five positions will support.
These are good templates to start with, then fill in the blanks with the combinations that suit your personal tastes.
Once the desired combinations are worked out for each position of the switch, you can translate that to an actual wiring diagram.
Let's review our understanding of the System Series/Parallel switch.
We have Four inputs from the pickup or coil selection.
SL/Hot
Gnd/Gnd
Hot/Hot
SL/Gnd
SL/Hot and Gnd/Gnd select the coil that will be the Foundation.
ie: It will be in the bottom of the stack when in the Series mode.
This pair will be on the left side of each drawing.
Hot/Hot and SL/Gnd select the coil that will be Raised.
ie: It will be in the top of the stack when in the Series mode.
This pair will be on the right side of each drawing.
These pairings will be the norm but they aren't the only way the four inputs can be paired.
More on this, later.
Let's move forward and begin to evaluate our first structure.
Version 1 employs a superswitch pole to serve each of the four inputs to the S/P switch.
Every coil is free-floating.
That means any coil can be used in either the Foundation group or the Raised group.
And regardless of the group we use to select the coil, we can select it in-phase or out-of-phase.
But we're limited to just ONE coil in each group,
so we have a maximum of two-coils in each selected combination.
Lots of flexibility but not much range of possibilities.
Single Coil sound:
By using the shunt-fader without a capacitor we can dial out the foundation group and hear just the raised group.
(This occurs only in the Series mode. In Parallel mode, the fader is out of the circuit.)
With a large value capacitor, most of the sound from the foundation group can be dialed out.
I estimate the 220uF capacitor will allow most of the hum-cancelling to remain.
Lower frequencies won't be shunted effectively but higher frequencies will.
Perhaps JohnH can weigh in and make a better recommendation for cap value.
Forced Singles:
If the optional shunt-fader is not employed, we can still get a single coil.
1 - We can wire the desired coil between Hot/Hot and Gnd/Gnd in that position of the selector switch.
and leave the other two inputs unused. But that ties up 2 of our 10 possible tonal choices.
2 - If we add another coil in that position between SL/Hot and SL/Gnd,
the additional coil will be present in the parallel mode but not in the series mode.
Recommendation:
Because of the two-coil at-a-time limitation, this structure isn't particularly useful without some local switching. In a HSH or HSS configuration, we might wire the bridge HB to a local S/P switch. That would open a few more doors. But it adds another switch. And life gets very complicated if we want to employ just one coil from the Bridge HB in a combination with one of the other pickups. But there is another way ...
In this variation of Version 1, we can evaluate the effect of pre-wiring a pair (or pairs) of coils into hum-canceling couplets. Parallel isn't possible between the two coils of the couplet, only series. But selecting that couplet as a pre-wired series pair means we can have three coils in some of our combinations. And no need for an additional switch.
If we choose to use just one of the coils from the couplet, this is best served by selecting it in the Foundation group. If Gnd/Gnd is connected to the local series link, there will never be a hanging from hot issue. If that means SL/Hot needs to connect to the (-) of the desired coil, that coil would be inherently out of phase. But that won't be a problem. Just select the coil used in the Raised group in the desired phase relationship.
If we select one coil of a couplet in the Raised group, the unused coil of the couplet will hang from the middle when the S/P switch is in series mode. Not the end of the world, but worth avoiding when possible.
Although we could have more than one couplet in our palette, I suspect many of the desired combinations of four coils can be achieved in Version 2 or Version 3.
I think I've covered most of the benefits and pitfalls of Version 1, so I'll open the floor to comments and/or questions.
The jolly round guy with the white beard isn't the only one with a sack full of presents.
I have three I'll be serving up, one thread each.
I've elected to put this in the Design Modules subforum because this is an exercise in meshing two modules together. Coil selection and a S/P switch. I previously covered the SP switch in this thread: Shifting Gears: The Series/Parallel module
All three installments will feature the same overall architecture:
- A 4P5T superswitch as the pickup selector
- A DPDT switch (perhaps a push-pull) as global Series/Parallel switch.
The difference between versions is how the four poles of the superswitch are assigned.
These structures are all intended for use with a master volume and master tone control,
(although two volume controls will be possible in some cases)
Since a Strat has three holes for potentiometers, I've included an optional shunt-fader to occupy one of the holes.
These drawings are more schematic than wiring diagram.
The intent is to provide a highly visual perspective of how the four poles serve us.
Wiring of each switch position is omitted for two reasons.
1 - elimination of clutter.
2 - there are far more combinations possible than the five positions will support.
These are good templates to start with, then fill in the blanks with the combinations that suit your personal tastes.
Once the desired combinations are worked out for each position of the switch, you can translate that to an actual wiring diagram.
Let's review our understanding of the System Series/Parallel switch.
We have Four inputs from the pickup or coil selection.
SL/Hot
Gnd/Gnd
Hot/Hot
SL/Gnd
SL/Hot and Gnd/Gnd select the coil that will be the Foundation.
ie: It will be in the bottom of the stack when in the Series mode.
This pair will be on the left side of each drawing.
Hot/Hot and SL/Gnd select the coil that will be Raised.
ie: It will be in the top of the stack when in the Series mode.
This pair will be on the right side of each drawing.
These pairings will be the norm but they aren't the only way the four inputs can be paired.
Let's move forward and begin to evaluate our first structure.
Version 1 employs a superswitch pole to serve each of the four inputs to the S/P switch.
Every coil is free-floating.
That means any coil can be used in either the Foundation group or the Raised group.
And regardless of the group we use to select the coil, we can select it in-phase or out-of-phase.
But we're limited to just ONE coil in each group,
so we have a maximum of two-coils in each selected combination.
Lots of flexibility but not much range of possibilities.
Single Coil sound:
By using the shunt-fader without a capacitor we can dial out the foundation group and hear just the raised group.
(This occurs only in the Series mode. In Parallel mode, the fader is out of the circuit.)
With a large value capacitor, most of the sound from the foundation group can be dialed out.
I estimate the 220uF capacitor will allow most of the hum-cancelling to remain.
Lower frequencies won't be shunted effectively but higher frequencies will.
Perhaps JohnH can weigh in and make a better recommendation for cap value.
Forced Singles:
If the optional shunt-fader is not employed, we can still get a single coil.
1 - We can wire the desired coil between Hot/Hot and Gnd/Gnd in that position of the selector switch.
and leave the other two inputs unused. But that ties up 2 of our 10 possible tonal choices.
2 - If we add another coil in that position between SL/Hot and SL/Gnd,
the additional coil will be present in the parallel mode but not in the series mode.
Recommendation:
Because of the two-coil at-a-time limitation, this structure isn't particularly useful without some local switching. In a HSH or HSS configuration, we might wire the bridge HB to a local S/P switch. That would open a few more doors. But it adds another switch. And life gets very complicated if we want to employ just one coil from the Bridge HB in a combination with one of the other pickups. But there is another way ...
In this variation of Version 1, we can evaluate the effect of pre-wiring a pair (or pairs) of coils into hum-canceling couplets. Parallel isn't possible between the two coils of the couplet, only series. But selecting that couplet as a pre-wired series pair means we can have three coils in some of our combinations. And no need for an additional switch.
If we choose to use just one of the coils from the couplet, this is best served by selecting it in the Foundation group. If Gnd/Gnd is connected to the local series link, there will never be a hanging from hot issue. If that means SL/Hot needs to connect to the (-) of the desired coil, that coil would be inherently out of phase. But that won't be a problem. Just select the coil used in the Raised group in the desired phase relationship.
If we select one coil of a couplet in the Raised group, the unused coil of the couplet will hang from the middle when the S/P switch is in series mode. Not the end of the world, but worth avoiding when possible.
Although we could have more than one couplet in our palette, I suspect many of the desired combinations of four coils can be achieved in Version 2 or Version 3.
I think I've covered most of the benefits and pitfalls of Version 1, so I'll open the floor to comments and/or questions.
