Idea for rhythm circuit mod

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gibs
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Idea for rhythm circuit mod

Post by gibs » Tue Jul 27, 2021 7:50 pm

Been looking at Rothstien’s super PTB wiring and the ultra and Am Pro II with their series/parallel switching and came up with an idea for a rhythm circuit mod, but not totally sure how to go about wiring it, if it’s even possible, thinking I’d need a 4pdt switch to pull it off, but not sure that’s even enough. So here’s the idea:

Lead circuit:
Typical jazzmaster, volume, tone, 3 way switch with parallel when in the middle.

Rhythm circuit:
When engaged, lead circuit is bypassed and both pickups are on in series, the roller knobs would become volume controls for each pickup, allowing you to blend the 2 coils for varying tonal flavors of series pickups. Kinda like a dial-a-tap.

In theory sounds great, but not sure if it’s possible, I think if the volume was for one coil it would’ve fine, but given this is a series setup, it might defeat the whole purpose of be able to control them separately. Does this seem like it might work? Anyone have an idea how to go about wiring this if it would work?

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noisepunk
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Re: Idea for rhythm circuit mod

Post by noisepunk » Tue Jul 27, 2021 8:04 pm

sounds possible–i haven’t tried to figure something like this out in a good while, but i’ll think on it and see if i can come up with something.

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HarlowTheFish
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Re: Idea for rhythm circuit mod

Post by HarlowTheFish » Tue Jul 27, 2021 10:08 pm

I don't think you could do two volumes, but you could probably do a series volume and a blend (basically a dialable split like you mentioned), then run out to the main tone pot if you wanted. Optionally (and IMO maybe more useful) you could do a blend and a bass rolloff that are only on when the series setting is engaged, then run to the lead circuit for vol/tone.

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Re: Idea for rhythm circuit mod

Post by jorri » Thu Jul 29, 2021 4:59 am

Hmmm 🤔 series means a single volume control, i mean it would have to control the whole path if wired normally.

But, you could wire something abnormally...
So a pot is in parallel with each series pickup.
The pot has resistance, then signal is thru pickup, the pot has no resistance signal goes thru wire, pickup shorted.

Actually this is kind of how a high cut "strangle pot" could work too.

Question is does it present other issues- idk yet, so maybe its an experiment. I dont see why it wouldnt but the pot value may take experimentation.

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gibs
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Re: Idea for rhythm circuit mod

Post by gibs » Mon Aug 02, 2021 6:02 pm

That was my thought as well, I could wire the volumes to the pickups, and get a similar control setup to a Gretch (individual volumes, master tone, master volume) I’ve considered it, but not sure about having the individual volumes when not in series, it’s more to control the series setup to get a little more from the bridge side and less from the neck side to get more of a cutting sound (I’ve lowered the neck pickup in my tele to essentially do this on that guitar, but rather have a preset volume for series).

A blend pot sounds like a good idea too, although I’d probably need to place it on the lower portion rather than in the rhythm circuit, since the only pots I’ve seen that fit the rhythm circuit are standard pots in 1 Meg and 50k. I could do a PTB setup in the rhythm circuit I guess if I can track down a reverse taper pot for the bass cut.

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Re: Idea for rhythm circuit mod

Post by DeathJag » Mon Aug 02, 2021 6:09 pm

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Last edited by DeathJag on Sat Aug 14, 2021 6:29 am, edited 1 time in total.

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jorri
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Re: Idea for rhythm circuit mod

Post by jorri » Tue Aug 03, 2021 3:46 am

gibs wrote:
Mon Aug 02, 2021 6:02 pm
That was my thought as well, I could wire the volumes to the pickups, and get a similar control setup to a Gretch (individual volumes, master tone, master volume) I’ve considered it, but not sure about having the individual volumes when not in series, it’s more to control the series setup to get a little more from the bridge side and less from the neck side to get more of a cutting sound (I’ve lowered the neck pickup in my tele to essentially do this on that guitar, but rather have a preset volume for series).

A blend pot sounds like a good idea too, although I’d probably need to place it on the lower portion rather than in the rhythm circuit, since the only pots I’ve seen that fit the rhythm circuit are standard pots in 1 Meg and 50k. I could do a PTB setup in the rhythm circuit I guess if I can track down a reverse taper pot for the bass cut.
True - is it possible to switch the volumes in? Maybe needs more switch poles but perhaps there is a clever way to. One thought is you only really need a single pickup controlled to get some blending effect, then pass through the lower 'master volume'.
..as personally i try and avoid blends as ime they seem to have certain issues with taper, not being full volume in the middle position and things. Maybe in the parralell volumes i suggested they work better though.

But yes you may want a log pot for that method...not sure if 'need' one if its a preset.

My jazz bass solution was based on there not being a lot of change when 'blend', its only practically one extra sound. So i have a five way selector with positions 2 and 4 being fixed resistors knocking off the volume of neck or bridge, just from measuring the pots before i got rid of them. Plus series independant and tone.

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Re: Idea for rhythm circuit mod

Post by jorri » Tue Aug 03, 2021 5:35 am

Just reading your previous post: if you want to only control the neck, it is possible to have a single "volume for neck in series only" off a standard switch...its only having dual volumes that are a problem to switch out the circuit.
So i could draw that if you go down that route

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