Post by stevewf on Jul 7, 2024 20:50:48 GMT -5
I was inspired by this thread. [Edit: guitarnuts2.proboards.com/post/113064/thread]
Now, maybe GN2 can make sure I've got this straight. It's about Half Out of Phase (or as I prefer, Filtered Out of Phase, "FOoP"). Specifically, it's about the filter itself: what components to consider and their arrangement.
The OoP Filter in a Parallel context
But to start, here's an example of how I understand to build a Parallel, Filtered out of Phase module with just 2 coils and a filter:
Two coils, out of phase, in parallel, with some sort of filter applied in series with one of the coils. I've chosen coils whose windings are in the same direction, so as to reduce hum when out of phase. This dictates that the magnets must also be the same polarity, to achieve both hum reduction and OoP.
Usually (i.e. in all the models I can recall seeing on this web), that filter consists of just a capacitor. The filter removes some of the signal from the coil, namely the lows are reduced. Since signals from OoP pickups tend to cancel one another, this means that the unfiltered pickup's signal comes through with less cancellation, namely the aggregate resulting signal has more lows.
A proposed model of a filter
The following is a zoomed-in look at one way to design the filter. I tried to make it more general than the "usual" filter, which is why it ends up a little busier than a simple capacitor. Messing with this stuff is a place where I particularly admit that don't know what the heck I'm doing, so nudges, slaps and gentle torture are requested to set me straight.
Disclaimer: I don't know what I'm doing when it comes to electronics, even simple RC circuits like the above. Still, the idea is to "soften" the effect of the filter when compared to one made from a simple cap, ending up with a sound that's closer to plain OoP.
Remembering that we're doing OoP, which is like being in "Opposite World", I figure that softening the filter will harshen the sound when in context. That is, if OoP is considered "harsh".
A typical filter uses zero value for R1 (using a plain wire), and infinite value for R2 (with no connection). The form of the filter resembles that of a treble bleed. After all, it's meant to let highs through and not so much the lows, like a TB. My weak understanding leaves me guessing that raising R1 and lowering R2 will have similar but not identical effect. And it might depend on whether the context is PFOoP or SFOoP.
So I wonder if I have anything terribly wrong with my understanding of the above. Like, is there really a difference in the sound with a low-val R1 vs high-val R2? Is the difference so small as to be negligible? Do I even have the cap in the right place, relative to the coil, for starters?
If the above is found reasonable, then moving ahead, here are two pairs of diagrams, meant to depict four juxtapositions of two coils in Series, Parallel, Out of Phase and Filtered Out of Phase:
I used the same form of filter in both SFOoP and PFOoP. In Series, changing the values of the resistors have the opposite effect from Parallel.
- In Series, increasing R1 will lessen the effect overall of the filter, as will decreasing R2 (but, I think, in different ways); as R1 rises, less signal gets shunted, and the two-coil sound will be closer to simple SOoP. As R2 lowers, more of the freq spectrum gets shunted (instead of the cap allowing only highs to get shunted), bringing the sound closer to single coil.
- In Parallel, as R1 rises, less signal from the coil is "allowed through", and the two-coil sound gets closer to single coil. As R2 lowers, more of the spectrum is allowed (instead of only the highs that the cap allows), and the two-coil sound gets closer to POoP.
Does all this sound sound? Thanks, Nuts.
Now, maybe GN2 can make sure I've got this straight. It's about Half Out of Phase (or as I prefer, Filtered Out of Phase, "FOoP"). Specifically, it's about the filter itself: what components to consider and their arrangement.
The OoP Filter in a Parallel context
But to start, here's an example of how I understand to build a Parallel, Filtered out of Phase module with just 2 coils and a filter:
Two coils, out of phase, in parallel, with some sort of filter applied in series with one of the coils. I've chosen coils whose windings are in the same direction, so as to reduce hum when out of phase. This dictates that the magnets must also be the same polarity, to achieve both hum reduction and OoP.
Usually (i.e. in all the models I can recall seeing on this web), that filter consists of just a capacitor. The filter removes some of the signal from the coil, namely the lows are reduced. Since signals from OoP pickups tend to cancel one another, this means that the unfiltered pickup's signal comes through with less cancellation, namely the aggregate resulting signal has more lows.
A proposed model of a filter
The following is a zoomed-in look at one way to design the filter. I tried to make it more general than the "usual" filter, which is why it ends up a little busier than a simple capacitor. Messing with this stuff is a place where I particularly admit that don't know what the heck I'm doing, so nudges, slaps and gentle torture are requested to set me straight.
Disclaimer: I don't know what I'm doing when it comes to electronics, even simple RC circuits like the above. Still, the idea is to "soften" the effect of the filter when compared to one made from a simple cap, ending up with a sound that's closer to plain OoP.
Remembering that we're doing OoP, which is like being in "Opposite World", I figure that softening the filter will harshen the sound when in context. That is, if OoP is considered "harsh".
A typical filter uses zero value for R1 (using a plain wire), and infinite value for R2 (with no connection). The form of the filter resembles that of a treble bleed. After all, it's meant to let highs through and not so much the lows, like a TB. My weak understanding leaves me guessing that raising R1 and lowering R2 will have similar but not identical effect. And it might depend on whether the context is PFOoP or SFOoP.
So I wonder if I have anything terribly wrong with my understanding of the above. Like, is there really a difference in the sound with a low-val R1 vs high-val R2? Is the difference so small as to be negligible? Do I even have the cap in the right place, relative to the coil, for starters?
If the above is found reasonable, then moving ahead, here are two pairs of diagrams, meant to depict four juxtapositions of two coils in Series, Parallel, Out of Phase and Filtered Out of Phase:
I used the same form of filter in both SFOoP and PFOoP. In Series, changing the values of the resistors have the opposite effect from Parallel.
- In Series, increasing R1 will lessen the effect overall of the filter, as will decreasing R2 (but, I think, in different ways); as R1 rises, less signal gets shunted, and the two-coil sound will be closer to simple SOoP. As R2 lowers, more of the freq spectrum gets shunted (instead of the cap allowing only highs to get shunted), bringing the sound closer to single coil.
- In Parallel, as R1 rises, less signal from the coil is "allowed through", and the two-coil sound gets closer to single coil. As R2 lowers, more of the spectrum is allowed (instead of only the highs that the cap allows), and the two-coil sound gets closer to POoP.
Does all this sound sound? Thanks, Nuts.
