Problems with a simple harness and rotaries

[frets]

[frets]

Oh Guitarnutz2, how do I get myself into these situations...
It’s newbie Frets here (oh Gawd), with a wiring harness that has pushed my paygrade...well, I was fired. Anyway, I have this friend (he does exist) who bought this EB0 bass that prior to his purchase, was upgraded to some Frankenstein version of an EB3. I’ve not seen it. Said friend begged me to build him a harness. I did so. A real EB3 from 1971, A solderless one. Took forever.
He hated it, said it was “too dark” - hated everything about it. Although he presently has it in the bass. Go figure. He then says, “Please build me a simple harness with .022 250K on the Neck and .047 500K’s on the Bridge. And can you make it solderless like the last time?” He’s a really good friend; so, I stupidly said “okay”. But what I forgot was that my skill set with rotaries is limited to the first harness I built him. So I use the harness diagram attached. It gives me Bridge and Neck Parallel and Bridge and Neck Series. But no individual pickups at all. I want: 1- either a 3p4t that is plain simpler; and, resolve what I must do to have the two volumes with the rotary. 2- Or, Should I go back and use part of the real EB3 harness and just take out the audio signal transformer and heavy caps; - or - 3 - is there a way to salvage a simple harness with a 3p4t rotary that can enable Bridge, Bridge and Neck Parallel, Neck, Bridge and Neck Series? I guess that’s exactly like #1. I appreciate any guidance and will follow any advice to get this thing off my table and off to Ohio. 

[newey]

Frets-
Your diagram looks OK. If you are not getting N or Br individually, then something else is amiss. How have you wired the V and T controls into this circuit?

[Deleted]

Sept 13, 2019 3:51:52 GMT -5 frets said:

Please build me a simple harness with .022 250K  on the Neck and .047 500K  on the Bridge.

22nF with 250K and 47nF with 500K .. i see you already have a nice 47nF Cap

And can you make it solderless like the last time?

It gives me Bridge and Neck Parallel and Bridge and Neck Series. But no individual pickups at all.
NB N2B >sounds like wired up wrong! get a AVO/Meter that has a BEEP test and FIND Pin one from Each of the 3 SIDES of the switch, then find Pin two... and work around. Your Circuit looks right to me too..

I want:
1- either a 3p4t that is plain simpler; and, resolve what I must do to have the two volumes with the rotary.
Just put the VOLUME and Tone Before the Switch, this would mean on the N2B bit you will have a Volume form the midway point!.. ALSO remember TWO Volumes will FIGHT with each other to take tones away.

2- Or, Should I go back and use part of the real EB3 harness and just take out the audio signal transformer and heavy caps; 


3 - is there a way to salvage a simple harness with a 3p4t rotary that can enable Bridge, Bridge and Neck Parallel, Neck, Bridge and Neck Series? 
NB N2B >sounds like wired up wrong! get a AVO/Meter that has a BEEP test and FIND Pin one from Each of the 3 SIDES of the switch, then find Pin two... and work around. Your Circuit looks right to me too..

[frets]

Okay, I didn’t even think about the beep test. The way it’s wired is a plain ‘ol volume with ground on #1 and hot on # 2 for both pots, then the two caps wired from volum 2 to tone 1. Tone is grounded at 2. Then it has the inputs from the switch and pickups to the inputs on the volumes. Lastly, the grounds grounded. That’s it. Thanks Newey and Angelbunny etc. for helping me with this.

[newey]

Then it has the inputs from the switch and pickups to the inputs on the volumes.

Not exactly clear what you mean here, but the reason I asked about V and T control placement was that this could potentially be a source of the problem.

To have individual volume controls for each pickup, they need to be wired before the switching, as angelbunny said.

Then this:

then the two caps wired from volum 2 to tone 1. Tone is grounded at 2

is also puzzling. Your picture shows 2 tone pots. Are you wanting one tone pot or two? And, 2 caps, both wired to same tone pot?

To have 2 volumes and 2 tones, one V and T for each pickup, you would wire each pickup in the following order of components:

Pickup=====>Vol pot+ tone pot======>rotary switch (as per your diagram)=======>output jack.

If you are wanting a single master tone with individual volumes, that will caused interaction between the vol pots unless you use a "dual gang" pot for the tone, a la JohnH's "Strat with 2 volumes" scheme. With the dual-gang pot, you would wire the tone pot just as if it was two separate pots, as in any std. SG or LP diagram.

In any event, from your verbal description of what you have, it doesn't sound like you have the order of components as above.

[Deleted]

if you let me go CRAZY ...
there are POTs that if you turn so far one side it TURNS off
that will find the Neck, Neck Bridge and Bridge positions

then you can put a Push Pull on one of the TONE pots to Link Neck 2 Bridge
and if you want another Push Pull on the other Tone Pot and do Phase on the Bridge if you wanted


-------------------

you can get a SMALL rotary Switch that is 4P5T that way you can do Phase in there too 
and if you only got 4 Holes (VVTT) you could Double up the Tone Pot in one HOLE and have your 3P4T/4P5T switch

[Yogi B]

Sept 13, 2019 11:48:06 GMT -5 frets said:

Okay, I didn’t even think about the beep test. The way it’s wired is a plain ‘ol volume with ground on #1 and hot on # 2 for both pots, then the two caps wired from volum 2 to tone 1. Tone is grounded at 2. Then it has the inputs from the switch and pickups to the inputs on the volumes. Lastly, the grounds grounded.

As both newey and @angeisbunny point out the positioning of the controls is important, but not only for the 'hot' output signal path, but also for the ground signal path: it is important that the grounding of the volume and tone controls of the 'upper' pickup in the series stack (the neck pickup, in your case) also needs to go via the switch, i.e. not directly soldered to the back of the pots.

Sept 14, 2019 17:20:01 GMT -5 @angeisbunny said:

if you let me go CRAZY ...

Well that's not really up to frets , and I don't think the pernickety friend would be approving.

[Deleted]

ahhhhhhhhhhhhhhhhh 

the Switch changes the Capacitor from 10, 22, 35 and 47nF on both sides 

could change the Switch on the VOLUME Pot to DUAL Pot with own PCB to turn off
would give you 3x2P2T switches if you wanted (with Push pull) as we need ONE to LINK Neck and Bridge

[sumgai]

Here are the problems I see with ange's circuit, just above:

1. No pup selector switch - frets want all 4 possibilities, presumably conviently;

2. In parallel or series, each normally grounded vol pot acts as a master, (the standard reason for reverse wiring);

3. In series or parallel, each ungrounded vol pot simply adds a resistance between the pup and output.  Often this is not enough to kill the signal, and certainly is unreliable as a blend control of any sort;

4. With only one vol pot ungrounded, the other pot is still a master;

5. In series and with both vol pots ungrounded, the N vol pot will have little effect, but the B vol pot will interact with all of the tone control circuitry, probably in an undesirable fashion.

The fix is simple:
a) Move the s/p switch to just before the output jack;

b) Move the ground terminal (and switch) of the N vol pot to the lower lead of the N pup, this will isolate the two pup control circuits from each other when in series.

6) The dotted line between the binary switches indicates that all 4 should move simultaneously, which makes the Truth Table an impossibility.

HTH

sumgai

[Deleted]

The problem is turning off the pickups ..

Hmmm
The capacitors are on a hexadecimal switch not sure how to show it .. they are stand alone switches within one package 


sorry i tried to use single switches to express have a Hexadecimal switch works

[sumgai]

ange,


Sorry to say, but I still see problems...

Consider that blue wire between Neck negative and the Bridge vol pot's terminal that we normally consider 'grounded'. In parallel, if you turn down the Bridge vol pot, you are sending the Neck negative straight to the output (if that switch is closed). Of course, this means no signal at all. (Both leads of the Neck are going directly to the output, and the negative lead is also grounded....) With the switch open, then the Neck will be heard.  (But of course, not the Bridge.)

In series we have some different problems, i.e. the Bridge 'hot' now has two paths to follow:

1) If the Bridge vol pot is all the way up, then the Bridge vol pot's entire resistance element is in series with the Neck negative terminal. That'll reduce the Bridge's contribution to the overall sound, by a rather large margin.

2) If the vol pot is turned all the way down, then the Bridge positive is connected directly (via the orange wire) to the Neck negative, but the Bridge tone controls still have that vol pot resistance element between them and the signal.

IOW, when in series your Bridge vol and tone controls won't act as expected.

BTW, when you wish to show separate switches that have a similar function (such as selecting tone caps), you don't need to use dashed lines, or a black box, or some other way of showing their physical function.  Instead, you should use labels.  For example, switches usually start with a capital "S", such as S1 or S2, like that.  Even though we usually see switch labels in Truth Tables, in your case above I don't think that's necessary.  A reader who studies it for a few moments will make sense of what your Truth Table says, even without labels. (I feel that including them would just make the table cluttered.)

HTH




sumgai

[frets]

Guys,
I got it to work. Thank you all for your help with this. I learned 1. how to wire a rotary; and, 2. I will never work on any harness with a rotary - they’re dreadful.

[sumgai]

frets,



So show us a diagram of your final build - inquiring minds wanna know!

Otherwise, good job.






sumgai

[frets]

[frets]

Lord help me!!

[sumgai]

Sept 18, 2019 19:48:31 GMT -5 frets said:

Lord help me!!

My name isn't "Lord", but I'll try to help... what is your request, my son?

[frets]

A quick hand drawing that please don’t spend a lot of time on, and is just the bottom of the rotary with the wires labeled, that would show how to connect two 2 conductor pickups to a 3p4t rotary so that it may give the bassist Bridge, B+N parallel, Neck, B+N Series (or a similar combination of the 4). Is such a simple drawing possible? My eye is twitching behind this harness. I thought I was pretty good until I hit this rotary, it had humble me. So much so, I grovel oh Great Sumgai, Sorceror of Wiredom.

[Deleted]

BEEP BEEP TEST.. or ill send PENNY WISE AROUND

A= Neck + .. B=Neck- .. C=Bridge + .. GND= Bridge -

[Deleted]

I dont agree with STATEMENT 1
the BLUE wire is GREEN and then when N2B becomes BLUE as the GROUND is taken away

I will look to take out the TONE from N2B as this will change the phase of the Pickup a bit 


i should of looked at my NOTES where to put the VOLUME switch.. 
NOTE when VOLUME is at ZERO the SWITCH comes in to EFFECT so not GROUNDING the CIRCUIT but more cutting the Pickups way out. This is a Simple way to do N, NB and B
Just acts like a NORMAL 2P3T/2P2T(On/on/On) Switch .. well more like 2P2T(On/on/On) 

As for the N2B .. THE Bridge Volume STEALS the Same Point to GROUND as the N-, so that when its Switch over to N2B the GROUND is gone and its just a LINK.  Same as if you where to take them ALL to one POINT of GROUND!!

[frets]

Thanks Bunny, your 12 lug drawing is most helpful.