Spin-a-split for one coil of a HB wired in parallel

[Jack TriPpEr]

I searched for existing threads on this topic and only found the following:

guitarnuts2.proboards.com/thread/6945

Are there any other threads where this concept is discussed?

I am planning to wire up a scheme to test out having a volume ctl for each coil in a HB wired in parallel - plus an otpion to filter one of the coils w an RLC circuit - but wanted to first read up on what others have written about their own experiments doing it.

Thanks

[newey]

If the HB is always going to be in parallel and not in series, then some of the issues mentioned by JonH will be avoided. You will still have the situation whereby, if you turn one pot all the way off, it will kill all output if both coils are in parallel. But people who play LP-style guitars with dual V and T knobs have that issue and seem to live with it OK.

Having one coil filtered vai a cap/resistor won't affect that wiring or the issue with the volume pots. Is the filter going to be switched in/out?

You didn't mention whether this will also have a tone control (or controls); dual volumes with a master tone control can also present issues of interaction between the pots.

[Jack TriPpEr]

Thanks for the input newey.


I made a mistatement about my scheme, sorry. Each pickup will have its own "master volume" control. Per pickup, only 1 coil of the pair will have a 2nd volume pot that attentuates that coil's volume. The signal not attentuated by that pot, will be a 2nd hot wire that attaches to the master volume for that pickup. So the master volume per pickup will have 2 hot wire inputs, one for each coil of that pickup.

I was thinking that the concern about one pot being turned down and killing all signal for both coils, would be avoided by me wiring each of the the master volumes in the "indepenent controls" fashion, where the pup hot wire and output wire to the jack/switch are swapped around from normal btw the left and middle lugs of the volume pot. Do you think that method will not resolve that particular issue?

Yes, the RLC circuit pass-through will be an option-only, turned on or off by a 2PDT switch.

[newey]

Apr 5, 2021 12:09:08 GMT -5 Jack TriPpEr said:

So the master volume per pickup will have 2 hot wire inputs, one for each coil of that pickup

It might work OK if the "master volume" for the pickup was a dual gang pot., so that the hot input from the coil with it's own volume is separated from the other coil going straight to the master V pot. If both hot wires are going to the same place, then I see problems. But let's let others weigh in.

[Jack TriPpEr]

newey

Here is a sketch of my idea of how the two volume controls would be connected for one of the humbuckers (wired in parallel).  Note that each vol ctl is wired in the "independent volume ctl" method.

Hope this helps in making clearer what I am planning to do.

[Jack TriPpEr]

Link to sketch: imgur.com/KjhtISW

[Jack TriPpEr]

In case the sketch is not viewable, the pots of the two volume ctls are individual / not shared btw the two, which is what newey expressed concern about.

Please let me know if the link to the sketch I posted earlier works or not, btw. I had a lot of trouble trying to either upload a pic and to post an image that was a link to a filehosting site, had to give up on that, and resorted to just posting the link to the filehosting folder.

[newey]

Apr 6, 2021 10:54:45 GMT -5 Jack TriPpEr said:

I had a lot of trouble trying to either upload a pic and to post an image that was a link to a filehosting site, had to give up on that, and resorted to just posting the link to the filehosting folder.

.

You can either use the "upload file" button on the upper right of the reply window- this uses the Cloudinary service, and you must first register w/ Cloudinary, and then go into your profile here to direct the upload button to your Cloudinary account. This is a bit of work but is the best method, as all your forum images will be in one place.

Option number 2 is to use the "Postimage upload" button on the upper left of the reply window. This is easier as no registration is required, but doesn't have Cloudinary's advantages.

But since you're having trouble, and since your avatar references "Three's Company", here you go:



I still think your volume pots are going to interact, but as I said, let's get a second opinion. A dual-gang pot for the master would resolve any issues, though, as I mentioned above.

[Jack TriPpEr]

Now re-trying PostImageUpload feature, but this time using Firefox Mobile browser. Yesterday I tried it using Chrome Mobile Browser, and it didnt work.

[Jack TriPpEr]

Apr 6, 2021 18:40:30 GMT -5 Jack TriPpEr said:

Now re-trying PostImageUpload feature, but this time using Firefox Mobile browser. Yesterday I tried it using Chrome Mobile Browser, and it didnt work.

.... aaaaannnnd, PostImage Upload feature also didnt work this time, using Firefox Mobile browser.


What image upload feature is known to work on this forum for Android Mobile browser types?

[Jack TriPpEr]

Also no-go in Opera Mobile Browser for Android

[Jack TriPpEr]

Testing image upload via Cloudinary

[ashcatlt]

I think that V scheme will work reasonably well. If you try to stick any sort of T in between there, things get complex. At best will affect both coils to the extent that the one is turned up, and I tend to think that by the time you’ve turned it down far enough to isolate them, the one coil won’t be contributing enough of anything to much matter. You will of course lose some treble from the one coil as it’s turned down anyway - that is higher frequencies from that coil will get quieter faster than lower because it is already an RL lowpass, and as R gets smaller...

[Jack TriPpEr]

ashcatlt

Thanks for taking a look

[Jack TriPpEr]

ashcatlt

See pic of revised scheme below.

If I moved the output wire of the 2nd coil to the left lug of the other volume pot, I believe that now makes the 2 volume pots fully independent, in parallel with each other, and now each volume is dedicated to their respective coils (i.e. neither no longer acts as a Master Volume for the pickup).  Would that resolve the potential concerns with the prior scheme?

[ashcatlt]

Not really, no. It kinda just means you need to turn two knobs to have the other pickup on its own.

[Jack TriPpEr]

ashcatlt

Yes, I had spotted the "trade-off" that the new scheme meant having to manipulate 2 ctls instead of just 1 per pickup. Btw, this wiring scheme is meant as an experiment only, I would never wire a guitar this way permanently. So ergonomic/performance concerns aren't a factor here.

But as far as what the earlier concern was, following is what I thought was that earlier concern:

Apr 7, 2021 12:39:04 GMT -5 ashcatlt said:

At best will affect both coils to the extent that the one is turned up, and I tend to think that by the time you’ve turned it down far enough to isolate them, the one coil won’t be contributing enough of anything to much matter.

Wouldnt relocating the output of coil 2's volume pot to the left lug of the other volume ctl eliminate the interaction effect that is being expressed above?

[ashcatlt]

Well, so, you need resistance between them to isolate, so when they’re both turned all the way up, any tone control is going to be a master tone for that pickup. Yes, with this new scheme, you can turn them both down to get that isolation, but these signals are already just barely loud enough to be audible over the cosmic wind, and turning them down further just to use filters to turn them down even more just doesn’t sound like a great idea.

Theoretically, yes, it does “help”, and I guess I should apologize for my curt answer above. In practice I honestly just don’t think it’s likely to work out well. If you’re just experimenting, then go ahead! Let us know how it turns out. Prove me wrong. But you kind of asked what we thought, and...

...I think it’s a lot easier to get a wider range of useable sounds playing with the series arrangement.

[Jack TriPpEr]

ashcatlt

Thanks once again!

I am not completely following the concerns expressed but that's ok.  As I know I have not shared *the entire* wiring scheme for this whole setup which I don't really want to do at this point.  So I thank you for providing insights based on the limited amount that I have shown.  Your insights have been helpful.

This weekend I will wire up the whole scheme and see what comes of it. 

I will post back later about any successes and challenges.

[Jack TriPpEr]

Update: I did finish wiring up the scheme last night. And all seems to be working fine. Over the next couple days I am going to review the different sounds and make some notes for myself, then after that reply here with a summary of the scheme and the results.