|
|
Post by frets on Dec 11, 2021 15:25:17 GMT -5
Hi Boys,
Sorry I’ve not been around, it’s been a madhouse. A Madhouse I say!!😸
Anyway, you guys know I’ve been on this coil split kick. I’ve been researching how to make a coil split sound better. By better, I mean not so thin and hollow, more rounded and Strat-like. And I want to do an RC circuit that will work on a one push pull, doing two simultaneous splits pot. I found one idea for a single split on Premiere Guitar that didn’t explain how to connect it to the switch. Same with Revstar’s Dry Switch. I didn’t get it. We all know about that - Ha! 😸.
So, here is what I want to achieve.
- an RC circuit placed on the DPDT either in series or parallel, that will best emulate a single coil. And it must serve two splits with one pull.
Can y’all help? As always, thank you!
|
|
|
|
Post by psiloguitarensis on Dec 11, 2021 17:41:51 GMT -5
ok howdy glad ya back.
so i understand ya better
you want to build an rc circuit to make each split coil sound flatter, fuller and more like a true single coil? on a dpdt or a pushpull switch?
so hitting a switch coils are split into a rc circuit for tone changes but coils are to be in series or parallel with each other at same time?
what type of POSITION selector do you have installed?
|
|
|
|
Post by newey on Dec 11, 2021 20:31:07 GMT -5
Splitting both pickups with one DPDT is easily done. Making it sound more like a single coil? Not so easy. Adding a cap and a resistor to the split coil will always cut some signal at some frequencies, you can't get more than you started with. A split HB coil is significantly smaller than a SC Strat pickup, that's a big part of the reason they don't sound the same.
|
|
|
|
Post by psiloguitarensis on Dec 11, 2021 20:53:10 GMT -5
i know splitting the coils is easily done with one coil active at a time.
but i swear he wants to split both coils run them through the rc circuit to shape the tone then link them in series so they are both acting as a single coil both active at same time for a NBxSB combo tone.
i dont see how that happens with a single push pull or dpdt installed. if this is possible how does one wire that up?
|
|
|
|
Post by newey on Dec 11, 2021 21:45:39 GMT -5
but i swear he wants to split both coils run them through the rc circuit to shape the tone then link them in series so they are both acting as a single coil That's not what frets said, she means the RC filter could be either in series with the split coil, or in parallel, but she's still splitting coils. |
|
|
|
Post by psiloguitarensis on Dec 12, 2021 0:17:05 GMT -5
Oh oops major misunderstanding there. Sorry about that
|
|
Deleted
Deleted Member
Posts: 0
Likes:
|
Post by Deleted on Dec 12, 2021 4:11:11 GMT -5
Just thinking out here.. Humbucker to Single SOUNDING Problem is you have two SINGLE Pickles NEXT to each other and effecting the magnetic field North x South as a Humbucker to maybe North x South and Tone it down with inductors/Capacitor  found a Humbucker that is 16K with 7.6H Thinking a Dummy Coil with 9K6 DC and 4H ( North x South ) + Dummy |
|
|
|
Post by reTrEaD on Dec 13, 2021 9:27:27 GMT -5
Hi Boys, Sorry I’ve not been around, it’s been a madhouse. A Madhouse I say!!😸 Anyway, you guys know I’ve been on this coil split kick. I’ve been researching how to make a coil split sound better. By better, I mean not so thin and hollow, more rounded and Strat-like. And I want to do an RC circuit that will work on a one push pull, doing two simultaneous splits pot. I found one idea for a single split on Premiere Guitar that didn’t explain how to connect it to the switch. Same with Revstar’s Dry Switch. I didn’t get it. We all know about that - Ha! 😸. So, here is what I want to achieve. - an RC circuit placed on the DPDT either in series or parallel, that will best emulate a single coil. And it must serve two splits with one pull.Can y’all help? As always, thank you! Unless we're talking about a 4PDT switch like the Fender S1 et al, you only have one pole per pickup to do the split. Typically we connect that pole to ground and the "pushed" throw is connected to the (-) lead of the HB. The "pulled" throw is connected to the series link between the two coils. There isn't a pole available to connect anything in parallel with the coil that remains in the circuit. So necessarily, whatever resistor and/or capacitor (whether in series or parallel with each other) we use in the "split" mode would have one end connected to the series link and the other end would connect to the "pulled" throw. You can experiment with resistors of different values in the 1k~10k range and see if that smooths things out for you. You could even add a cap in parallel with that resistor, although that would brighten things up a bit from the sound you get with just the resistor. But if the cap is in series with the resistor, that would tend to castrate the lower frequencies. The opposite of what you're trying to accomplish. A different approach (that seems more promising to me) would be to not fully split the HB. Leave the two coils of the HB wired in series in both positions of the switch. But in the "pulled" mode, have a rather large capacitor (47 ~ 200nF) between the series link and ground. The lower frequencies (fundamentals) from one coil would still be present but the higher frequencies (harmonics) would be shunted to ground. This will get you all the harmonics from just the other coil. |
|
|
|
Post by jhng on Dec 13, 2021 11:50:04 GMT -5
A different approach (that seems more promising to me) would be to not fully split the HB. Leave the two coils of the HB wired in series in both positions of the switch. But in the "pulled" mode, have a rather large capacitor (47 ~ 200nF) between the series link and ground. The lower frequencies (fundamentals) from one coil would still be present but the higher frequencies (harmonics) would be shunted to ground. This will get you all the harmonics from just the other coil. I don't know much about HBs, but that kind of 'half-series' option sounds like an excellent solution. It's easily done on a single DPDT and would give a more SC like top-end without losing the body. Also, if you wire the DPDT so that in effect the cap is wired across the half-shunted coil rather than to the general ground, then you could still have series or out of phase options between the two pickups. |
|
|
|
Post by sumgai on Dec 13, 2021 23:03:16 GMT -5
So, here is what I want to achieve. - an RC circuit placed on the DPDT either in series or parallel, that will best emulate a single coil. And it must serve two splits with one pull. It took a few minutes to get my head together before I pulled this little chestnut out of the fire. Provided that you can live with a series connection for the resistor-and-capacitor, and you can live with either the North or the South as your single coil (the two labels are interchangeable), here ya go:  Alternatively, you may connect the resistor/capacitor combination to the 'hot' line, instead of ground. This will allow you to select which coil (screw versus slug) you have as the in-circuit single coil, and thus keep humbucking intact. Where your customer ordered mis-matched pickups, of course.  Almost forgot to mention: you can wire the cap-and-resistor in series as shown, or in parallel between the switch and ground. Either way will work, but your tonal results will likely vary. Experimentation is the name of the game!  EDIT: This is an exercise in logic, nothing more. But I want to point out two things: a) I'm not the correct person to speak with about humbucker pickups. I don't think highly of them, so my opinion as to their tone is highly suspect, as they say in the police reports. b) I have, without thinking about it at first, implied that one must use 2 resistors and 2 capacitors. If one were either cheap, or needed to conserve space in the cavity, one could just as easily combine the two switch pole terminals, and send the "single coil" connections to ground through the same resistor/cap combo. As to what the sound will be like in doing so, I haven't a clue, and per item a), I would humbly request that you ask others for opinions and/or guidance. Also, if you find yourself putting one split-pup to ground, and the other to 'hot', then it's obvious that this "save on component costs" isn't gonna happen. </ edit> Unless we're talking about a 4PDT switch like the Fender S1 et al, you only have one pole per pickup to do the split. Not quite correct. Note that I've shown only one pup and one half of a DPDT push/pull, as per frets' request. The remaining components for the other pickup and half of the push/pull are just duplicates of those shown. Now if a mini-toggle were allowed, a DP3T could allow for selecting the North or South coil at the user's choice, and a 4PDT or 4P3T could allow for a resistor/capacitor in parallel with the chosen coil. That would be interesting, to me at least. But admittedly, the cost of the components, and the necessary space, will increase quite a bit. (The experimenter in me is squeaking "SO BLEEPING WHAT?"!) HTH sumgai |
|
Deleted
Deleted Member
Posts: 0
Likes:
|
Post by Deleted on Dec 14, 2021 1:22:55 GMT -5
So, split the coil then add/subtract to make it sound like a single
Or keep the humbucker and go down.
------
Pickup in series with RC
Inductor + RC =
inductors resistance+R &
1/(1/ inductors capacitance + 1/C)
Pickup in parallel with RC
1/(1/inductors resistance)+(1/R)
Inductors capacitance C
Pickups C and R will flux a bit
Guess it's finding the best for a few different types trying to find some kind of ratio
-------
sumgai has up the single coil resistance and lowered the capacitance.
|
|
|
|
Post by Yogi B on Dec 14, 2021 2:21:01 GMT -5
I’ve been researching how to make a coil split sound better. By better, I mean not so thin and hollow, more rounded and Strat-like. So maybe like some middle point on a series blender? When switched to partial bypass, the below is essentially Type C from JohnH's Blending coils in series albeit with fixed resistors (the values of which being equal means the bypassed coil is roughly 6dB quieter than the other coil — probably a good starting point but may need tweaking). There's a couple of different ways around you could wire this — the way I've elected to show is the most 'universal', in that it only requires a 3-wire HB (hot, tap, and shared shield+signal ground). |
|
|
|
Post by reTrEaD on Dec 14, 2021 8:39:08 GMT -5
Unless we're talking about a 4PDT switch like the Fender S1 et al, you only have one pole per pickup to do the split. Not quite correct. I'm 100% correct given the limitations expressed in the OP. Since frets specified "one push pull, doing two simultaneous splits", she's obviously wanting to avoid additional holes. Therefore, mini-toggles are outside of her stated requirements. Note that I've shown only one pup and one half of a DPDT push/pull, as per frets ' request. And the fact that you have a capacitor as well as a resistor in series with the remaining coil, basically insures that the "thin" sound she's experiencing with a split HB will get worse, not better. |
|
|
|
Post by reTrEaD on Dec 14, 2021 9:04:33 GMT -5
A different approach (that seems more promising to me) would be to not fully split the HB. Leave the two coils of the HB wired in series in both positions of the switch. But in the "pulled" mode, have a rather large capacitor (47 ~ 200nF) between the series link and ground. The lower frequencies (fundamentals) from one coil would still be present but the higher frequencies (harmonics) would be shunted to ground. This will get you all the harmonics from just the other coil. I don't know much about HBs, but that kind of 'half-series' option sounds like an excellent solution. It's easily done on a single DPDT and would give a more SC like top-end without losing the body. Also, if you wire the DPDT so that in effect the cap is wired across the half-shunted coil rather than to the general ground, then you could still have series or out of phase options between the two pickups.Interesting point of discussion. In the case of the overall circuit having a "both pickups in series" option, it would definitely be necessary to have the capacitor across the half-shunted coil. If that option is not part of the design but out-of-phase is, having the capacitor between the HB series link and general ground would exchange the roles of the two coils. That might be feature or a fault. Rather than "half-series", I'd prefer to call this "semi-split". But either way, the gist is pretty much the same. We're featuring the harmonics from only one coil. |
|
|
|
Post by sumgai on Dec 14, 2021 15:40:06 GMT -5
And the fact that you have a capacitor as well as a resistor in series with the remaining coil, basically insures that the "thin" sound she's experiencing with a split HB will get worse, not better. You know this, I know this, but I did exactly what frets wanted, nothing more, nothing less. To wit: So, here is what I want to achieve. - an RC circuit placed on the DPDT either in series or parallel, that will best emulate a single coil. And it must serve two splits with one pull. After two years here in The NutzHouse, I figure that frets is the kind who learns best by doing, and she has proven time and again that she's not afraid to get her hands dirty. Besides, up to this point, I haven't see you offering any words of deterrence during this thread. frets, reTrEaD is correct - if you want to reduce thinness (i.e. add body back to the tone), then a capacitor in series with a coil isn't the way to go. At this point I'd suggest that you re-read his reply above about not splitting the pickup. Here, let me quote it for you: A different approach (that seems more promising to me) would be to not fully split the HB. Leave the two coils of the HB wired in series in both positions of the switch. But in the "pulled" mode, have a rather large capacitor (47 ~ 200nF) between the series link and ground. The lower frequencies (fundamentals) from one coil would still be present but the higher frequencies (harmonics) would be shunted to ground. This will get you all the harmonics from just the other coil. We call this a "broadbucker', and various members here have done this many times, starting with ashcatlt all the way back in 2007. However, the diagram in his post is history, so I've had to resort to borsanova's post, which has some diagrams. Check this out: borsanova's Broadbucker That outta keep your thinking cap working overtime! HTH sumgai |
|
|
|
Post by JohnH on Dec 14, 2021 16:52:37 GMT -5
I've played around with these issues too.
At the neck, I liked just a full simple split to one coil.
But at the bridge, after trying a few options, i like to keep both coils in series and bypass the bridge-side coil with a 0.047uF cap. This keeps the full edgy treble of one coil with some extra low-mids weight from the other.
|
|
|
|
Post by ashcatlt on Dec 15, 2021 15:49:55 GMT -5
...starting with ashcatlt all the way back in 2007. However, the diagram in his post is history... Just to say that I did not make this up. My post may have been the first you found, but I'm sure I got the inspiration from around here somewhere, and I doubt I was actually the first to implement it. Sorry about the images. We've been through some things. I probably do have a lot of those floating around somewhere, and trying to sort at least some of them out has been on "the list" for a while, but that list keeps getting longer, and this particular project never really seems to get any closer to the top... I will mention that I have both intra- and inter-pickup broadbucker available on a few of my guitars, and honestly never really use them. There certainly is more low end than a single and more top end than an HB, but in my experience, the two don't really end up meshing very well. I've never done much in the way of science to figure out what's going on. It always sounds feels unbalanced and unnatural. Part of me wonders if there isn't some sort of mid scoop happening, but whatever. Course, then, I don't much mind the sound of my split HBs as it is. I'm no kind of snob and really tend to prefer HBs anyway, but when I do want that brighter sound, I just go for the full split or a parallel combination. |
|
|
|
Post by frets on Dec 15, 2021 19:08:21 GMT -5
Guys, I’m sorry I’ve not responded. I’ve not checked back in a few days. Thank you all for your help. You know me, I’ll try anything, I put the below together and tested it. It’s giving me what sounds like a filtered split when pulled up. Please pick apart and tell me how silly I am😸.   |
|
Deleted
Deleted Member
Posts: 0
Likes:
|
Post by Deleted on Dec 15, 2021 22:13:30 GMT -5
I like the suggestion of keeping it as a humbucker and just dulling it down to sound more single.
We can't add but can always play or take away freqs
Single Coil Mimic
|
|
|
|
Post by Charlie Honkmeister on Dec 29, 2021 9:42:05 GMT -5
Frets,
This is a very timely topic for me as well and I'd like to offer some really good links and a little bit of my own experience on partial coil splits. Some of this has been talked about on this thread, and I think you are well into approach #2, but I wanted to give some of the material "fresh" for reference for some folks in the community who might need it.
All of these circuits would meet your requirements for a single switch that splits both pickups at the same time with one switch. Possible exception of #1 below. Yeah, there might be a couple of parts hanging off the switch, but that's why God invented heat-shrink tubing. 
1. TDPRI Partial Coil Split Theory and Discussion
Great straightforward explanation and diagrams here. Moosie mentions the PRS partial split method they use on the S-2 and Core HH models - a simple resistor shunt of one coil. He also mentions a method tried by Gibson - just a capacitor to shunt across one coil.
The interesting thing about Moosie's approach is that he uses a bass cut cap between the coils and then uses a simple resistor shunt to either hot or ground to attenuate the desired coil in the humbucker.
Moosie has done a lot of work on experimenting and listening (including building test rigs) and I think his approach is a great starting place. I have built this into one of my project guitars and it does work. (Really well, but I'm in love with approach 3 below.) Hats off to Moosie. Whether Moosie knows it or not, he's in the GNuts2 tribe.
There's a 4PDT mini switch available if you can tolerate a separate mini split switch instead of a 2PDT push-pull switch that's ganged with a pot. You could do just about any scheme you wanted (including series/parallel coil switching) with one of these. I have bought these and am using one, and they're just fine as well as very compact.
2. Dirk Wacker - Ultimate Guitar, Fender Select Carved Top Jazzmaster
Dirk discusses the partial coil split found on the Fender Select Carved Top Jazzmaster. It is a capacitor and a resistor in series, to shunt the selected humbucker coil.
There's some interesting discussion on different coil split approaches and suggestions for component values, but Dirk kept it pretty non-technical, which might slightly frustrate some of the electronics and theory folks here on GNuts2. However, Dirk did a great job of providing enough information to allow a good start for experimentation.
3. .strandberg* HSX Circuit
This is a partial coil split circuit that Strandberg (.strandberg*) has introduced in conjunction with their Michael Frank-designed pickups, on certain Strandberg models, particularly the
Strandberg Boden Fusion 6 LE Titanium.
The module is available from .strandberg* separately for $44.00 plus shipping.
The module has four wires - one wire to the coil split point, one to ground, one to pickup output hot (top of volume control), and one wire to the wiper of the volume control.
This is an epoxy-encapsulated sealed circuit and I haven't really tried to reverse engineer this, but as a total guess, this "looks" like a combination of a treble bleed across the volume, combined with a partial coil split which uses BOTH split points on both the bridge and neck pickups at the same time (in other words, connects the two "coil tap" points of the two pickups together regardless of which pickup is selected, and uses probably a capacitor and resistor in series from that point to perform the shunt/coil split. I could be and probably am wrong, but this is what it smells like. If you look at the wiring diagram above, this is done with a single 2PDT switch like you wanted.
What the main idea here is for experimentation, is to connect the two coil split points (AKA series coil link ?) from both the bridge and neck together, and use a series resistor/capacitor combo to connect that to either ground or hot to do the partial split.
A 3.9K Ohm resistor in series with a .047 uF cap would be as good a starting place as any for this mod, using Dirk Wacker's suggested values for a single pickup. Yes, I know that those values are suggested for a single pickup and we are doing both at once with one shunt, but let's start somewhere and season to taste.
Whatever the circuit topology is in that little module, the results as I tried in my own guitar with the splits engaged, are very close to PFM (Pure Freaking Magic.)
I want to add that my wiring configuration is shunting the outside coils of the neck and bridge and using the inner coils full strength. This is identical to what Strandberg does but it seems a bit counter-intuitive since the outside coils have the most bass and treble, one would think. But I can't argue with the results.
There's definitely a lot of midrange cut; the sound of both the neck and bridge pickups selected separately when split, sound definitely "acoustic-like" but also "single-coil-like". Super useful and musical.
However, the "both pickups selected position" - gives a very usable, Knopfler-eque, Strat position 2 (neck/middle) quack! From a 2 humbucker guitar no less! I would not have believed it if I hadn't heard it.
The bridge by itself when split has a very,very slight touch of "quackiness", but sounds extremely good for a single-coil emulation. A hotter bridge PU might shift that balance a bit but I'm happy with what's there now.
There's been some discussion on the DiMarzio forum about the HSX and the poster (1) wasn't very impressed with the Fusion 6 pickups/HSX combination, (2) believes that the HSX would work best with vintage type lower output pickups, and (3) believes that you can get further for a lot less money with just a series resistor/capacitor shunt a la Dirk Wacker article under #2 above, just as I'm suggesting.
I was using a 4.3 Henry/6.1K DCR neck rail pickup (wound with AWG 41) built with Mojotone parts, and a commercial Calig rail pickup (Calig H67) with 6 Henry/8.8K DCR for the bridge. So maybe my PU's were in the range that the HSX will work best with. If you can replace a $44.00 module with 85 cents worth of parts, I'm down with that.
Also BTW, notice on the Strandberg wiring diagram that there's a 12K resistor on the tone control. This is a Very Good Thing; it lowers the tone control loading a little bit, and partially prevents complete descent into the "mud zone" that most of us despise with the traditional tone control when it's turned all the way down. Since someone decided to put that on a $3K+ guitar with a single tone control -- sure, I'm going to pay attention.
If there's any way I can get Michael Frank ( I believe this is the same person as Michael Frank-Braun, chief engineer at Fender) to reveal the HSX circuit for us DIY experimenter types, I will do that. But based on history and the Fender Jazzmaster circuit which I am inferring that he had a part in designing, I think we can get to a reasonable facsimile of what I found with the HSX by trying out the topology I outlined.
Take care, -Charlie
|
|
|
|
Post by psiloguitarensis on Dec 31, 2021 0:20:09 GMT -5
frets nothing silly about that if it works lol. btw way alot of ideas are silly until they fruit. i noticed my new humbucker when bridge only is selected my 3 way doesnt affect tone as much when selecting s/p/sc as much as it does when in pos 2 parallel with middle pickup. in pos 1 tonal changes are minimal but in pos 2 bridge sounds exactly like a single coil should and doesnt sound half bad though bright like a sc but thin like hb in series. if a humbucker is on a (3way on/on/on switch) are you able to have the single coil mode on a 250k tone pot and full humbucker mode on a 500k pot?
|
|
|
|
Post by newey on Dec 31, 2021 7:25:02 GMT -5
if a humbucker is on a (3way on/on/on switch) are you able to have the single coil mode on a 250k tone pot and full humbucker mode on a 500k pot? What would the third switch position be doing? If all you want is to switch between full HB and SC, a DPDT On-On will allow you to do so- one pole selects SC versus HB, the other pole selects the tone pot. But if the 3-way is doing series/parallel/SC, then both poles are used and there's no room for switching pots. You'd need a 3-pole switch, which are rare, so as a practical matter, it means a 4-pole switch (much more commonly available). |
|
|
|
Post by Charlie Honkmeister on Dec 31, 2021 9:49:45 GMT -5
You're not going to get much by switching tone pot values; especially if you are doing the 3-way on-on-on series/split/parallel on the bridge pickup. Ain't worth doing IMHO.
A toggle switch which allows the series/split/parallel setup ( has 2 poles as DPDT on-on-on, and 1-2 poles of whatever) is going to be a very challenging parts search, as newey mentions above.
A tone pot with capacitor is still mostly just a resistive load to the AC pickup signal until it's around halfway down. So, unless you like mudtone, just shunting the 500K volume or tone pot with a 500K (470K or 510K standard value) resistor will do basically the same thing. But then, you've improved just one mode out of series/split/parallel.
I think that having one really good-sounding partial split is better than having series/split/parallel on the bridge. This thread is on the right track. I've tried a lot of things over the years. Partial split works better in not having the pickup sound too thin, it works better in terms of less output drop, and it works better in that you don't totally lose hum-cancelling, and you can trade off these qualities to a certain extent and have a greater chance to get to a sweet spot that you like and that works for your rig and what you're playing.
I do like parallel coils for the bridge, especially for super-hot bridge PU's, but it's such a radical change in inductance and DCR (1/4 of the inductance and DCR of the series coil connection) and output that you need to optimize the rest of the volume/tone circuit, and gain and EQ in your amp/pedals, to get the most out of it. And then, it's a hassle to try to make everything work in combination with the other PU's in the instrument. And then, tweaked as far as it can go, it still might not be as good as you want it to be for real single coil -oriented musical styles.
|
|
|
|
Post by Charlie Honkmeister on Dec 31, 2021 11:03:41 GMT -5
Hey, just another reference here.
(Please indulge me if you know this stuff already, but this thread is going to be found a lot in searches on the forum, coil splits are a very timely topic, and I wanted to give new folks a good set of references in the thread instead of them having to search in dozens of posts.)
If you are doing total or partial coil splits on both PU's with one switch, you have two pickups from the same manufacturer, and you want, let's say, the north coil on one humbucker and the south coil on the other humbucker to be active, you normally split one PU to hot and one PU to ground.
If you want to split both PU's to hot or ground, use north coil of one pickup and south coil of the other, and retain some hum cancelling when both bridge and neck are selected and the split is active, you will need to wire one of the PU's "inside out."
("Inside out" may seem confusing; what you really do is "re-stack" the coils from ground to hot, but "inside coil split point wires go to outside and outside wires become new split point" is definitely too long.)
Here's a good, well-written link with text and diagrams to explain this idea. It uses DiMarzio pickup color codes but you can easily understand and translate this to other PU manufacturer's products.
Flipping the magnet together with inverting the polarity of the pickup hot/ground connections would do the same thing as "inside out", but with the big disadvantage of having to open up the pickup.
|
|
|
|
Post by frets on Dec 31, 2021 12:35:58 GMT -5
Thanks Charlie😺😺😺
|
|
|
|
Post by Yogi B on Dec 31, 2021 13:18:11 GMT -5
All of these circuits would meet your requirements for a single switch that splits both pickups at the same time with one switch. Possible exception of #1 below. ... 1. TDPRI Partial Coil Split Theory and Discussion TDPRI Partial Coil Split Theory and Discussion - Moosie... There's a 4PDT mini switch available if you can tolerate a separate mini split switch instead of a 2PDT push-pull switch that's ganged with a pot. While you could use a 4PDT for that scheme, a DPDT would also work (one SPDT per HB). That scheme is almost but not quite exactly the same as the one I posted above. Yes it's tuned and arranged differently, but the only real change is that Moosie's 6k2 resistor is in parallel with the coil rather than coil + cap combination. (The other resistor I have, parallel with the cap, is the counterpart of the later added anti-pop resistor.) Thus the 'fix' to turn mine into an equivalent of Mooise's is to swap the wires that connect either side of the cap to the switch. This is also true of the above wiring too (the Jazzmaster, not that it's any surprise that DW seems to have failed to notice this, or at least didn't understand the implication this has) — and to be honest I'd call this approach cheating. (This also partially answers sumgai's earlier musing of this idea: b) I have, without thinking about it at first, implied that one must use 2 resistors and 2 capacitors. If one were either cheap, or needed to conserve space in the cavity, one could just as easily combine the two switch pole terminals, and send the "single coil" connections to ground through the same resistor/cap combo. As to what the sound will be like in doing so, I haven't a clue ) When the series links of both humbuckers are joined together (and partially split via just one impedance), how many coils are contributing to the output? Say we have the neck partially split: we have the full output from one of the necks coils, reduced output from the other neck coil, and that's it right? Nope! With connected series links you'd also have a (roughly) equally reduced output from one of the BRIDGE coils! (Assuming your switching scheme doesn't deliberately avoid this by un-grounding the supposedly disengaged coil.) I shan't argue that this is an unintentional oversight that ought to be promptly 'corrected' for the sake of purity. It clearly produces desirable results and Strandberg seem pretty well aware of this 'quirk', taking a closer look at the pickup selection graphics in this demo — one of the coils from the opposing pickup isn't fully faded out. (That being said it's not quite accurate either: it should show two partially faded coils, the outer coils of both HBs. Nevertheless it seems too much a coincidence and I have faith that the people at Strandberg are competent enough to mostly know what they're doing — though looking at convoluted Megaswitch wiring in the diagram you linked, perhaps not.) I do, however, think it is unfair to characterise this as a "partial split" without acknowledging the involvement of influence from the other humbucker.
If proceeding down the route of equating "partially split" to "seemingly partially split, but including other coils", then my vote for best single coil emulation would be using the other humbucker wired in parallel out-of-phase, to partially bypass one coil of the split pickup. Done properly this will be as hum-cancelling as the full humbucker, the impedance and output being about 1 1/ 3 of an actual split isn't a terrible match for a true single coil, and the higher harmonics that aren't cancelled by phasing of the coils add a welcome zing to the top end. The downside of this approach is that, because this is a more involved setup, the switching cost is variable and dependent upon the rest of the circuit (ranging from requiring only a SPST all the way to impossible without also requiring a more powerful main selector switch). An additional caveat is, due to the use of all four humbucker coils, obtaining a Tele-esque sound (neck partially split + bridge partially split) utilising this method is an impossibility (at least, not without a third humbucker). |
|
|
|
Post by psiloguitarensis on Dec 31, 2021 18:07:52 GMT -5
newey in generl i was speaking as if a 3way is wired series parallel split coil could that split coil be placed on a 250k tone pot with a cap but i see what you were saying wouldnt help fill the tone back in. so my next question is if i removed the current jumper for a res to shunt the coil partially or even a cap and res combo to help the tone?
|
|
|
|
Post by newey on Dec 31, 2021 18:16:48 GMT -5
Not sure exactly what you mean by "the current jumper", but you can partially bypass one coil with a cap, as we have been discussing in another thread recently. Doing so with a resistor would simply cut output across all frequencies, the idea here is that the cap can be sized to emphasize the high end so as to better mimic a SC.
|
|
|
|
Post by Charlie Honkmeister on Dec 31, 2021 19:13:39 GMT -5
All of these circuits would meet your requirements for a single switch that splits both pickups at the same time with one switch. Possible exception of #1 below. ... 1. TDPRI Partial Coil Split Theory and Discussion TDPRI Partial Coil Split Theory and Discussion - Moosie... There's a 4PDT mini switch available if you can tolerate a separate mini split switch instead of a 2PDT push-pull switch that's ganged with a pot. While you could use a 4PDT for that scheme, a DPDT would also work (one SPDT per HB). That scheme is almost but not quite exactly the same as the one I posted above. Yes it's tuned and arranged differently, but the only real change is that Moosie's 6k2 resistor is in parallel with the coil rather than coil + cap combination. (The other resistor I have, parallel with the cap, is the counterpart of the later added anti-pop resistor.) Thus the 'fix' to turn mine into an equivalent of Mooise's is to swap the wires that connect either side of the cap to the switch. Yogi, I definitely buy the idea that your version would work; the bass cut cap placement isn't critical and using your scheme would save one set of switch contacts that would be needed in Moosie's version to short out the cap for full humbucker mode. I mentioned the mini 4PDT because I've recently been experimenting with this and the 4PDT allows a larger range of things to try.
|
|
|
|
Post by Charlie Honkmeister on Dec 31, 2021 19:58:33 GMT -5
... What the main idea here is for experimentation, is to connect the two coil split points (AKA series coil link ?) from both the bridge and neck together, and use a series resistor/capacitor combo to connect that to either ground or hot to do the partial split.This is also true of the above wiring too (the Jazzmaster, not that it's any surprise that DW seems to have failed to notice this, or at least didn't understand the implication this has) — and to be honest I'd call this approach cheating. (This also partially answers sumgai's earlier musing of this idea: b) I have, without thinking about it at first, implied that one must use 2 resistors and 2 capacitors. If one were either cheap, or needed to conserve space in the cavity, one could just as easily combine the two switch pole terminals, and send the "single coil" connections to ground through the same resistor/cap combo. As to what the sound will be like in doing so, I haven't a clue ) When the series links of both humbuckers are joined together (and partially split via just one impedance), how many coils are contributing to the output? Say we have the neck partially split: we have the full output from one of the necks coils, reduced output from the other neck coil, and that's it right? Nope! With connected series links you'd also have a (roughly) equally reduced output from one of the BRIDGE coils! (Assuming your switching scheme doesn't deliberately avoid this by un-grounding the supposedly disengaged coil.) ... There's another way to look at this twist on the "partial coil split." Once we do a partial split of one PU and introduce some of the shunted coil back in, what we're doing just from the point of view of the output and the "naked" unshunted coil, is introducing another RLC element either above or below the unshunted coil. Adding the coil from the other PU to the shunt RLC just modifies that RLC that's in series with the naked PU coil(s) that is/are selected ( from a passive component point of view), and makes that combined shunt RLC impedance constant for any selected PU combination.
From a signal generation point of view, you have some sort of a constant filtered mix of both shunted coils that can add to (in a gross signal sense) whatever "naked" coils are selected on the 3-way. So, as you are pointing out, when you split in this way, you really never can get just one pickup any more when the split is engaged. But maybe that's not such a bad thing.
Because of seeing it done this way in both the Jazzmaster design and the Strandberg design, and also hearing the results when I tried the HSX, there's some indication that adding that constant mix of both shunted coils is sonically useful for all positions of the 3-way switch, maybe even better than partially splitting the pickups individually.
Thanks for catching that the Jazzmaster is connecting the split points together.
It ain't cheating if it sounds good IMHO, but if it makes some people happier, we can call it something else besides a "partial coil split." Maybe "aggregated hybrid coil split" or something like that.
Both in the Strandberg and in my own testing, the active coils are the inner (inboard) coils and the shunted coils are the outer coils. I haven't sussed out the S-1 wiring on the Jazzmaster but I wouldn't be surprised if it was set up the same way.
Along the lines of different RC shunts for the two pickups, I'd also like to suggest that one can put a resistor between the two pickups' split points to partially isolate or rebalance the "mix" and also be able to make a single RC to hot/ground have more effect on the neck PU side or more on the bridge PU side. Just tossing that out for the bold and adventurous with more time than I have. 
|
|
