Wiring & Pickup question -Chromium ?

Started by Barklessdog, July 03, 2008, 03:13:50 PM

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Barklessdog

On the pickups there are three wires a white one that is attached to one side of the coil. A red one attached to the other side of the coil and a orange one that appears to be attached to a metal plate/magnet?

The schematics only show I use two wires. Which one is the ground and which of the other two wires do I use ??



Other question- observation.


dots are the contacts in that position



Chromium's diagram -Thanks


If each square represents the switch position contact sets, why do some of the pickup wires attach to the other positions that would not be in contact in that pickups position?


sniper

i'm kind of a dummy when it comes to electrifications but it seems there are three constants 3, 7, 11) on your rotary diagram and two (3, 11 but no 7) on your two disc diagram. are you trying to mix apples and oranges with a single disc vs a two disc switch? which makes me ask the question do you need a 3p4t single wafer like a later or early eb3 switch instead of a two disc switch (both are available) which might have different constants even though the later is a 3p4t, but also can carry independent circuits if the third common constant isn't used.

the third circuit would also be the shunt to either coil or cutoff switch for the none loading dummy coil when it isn't needed. i wish i was more than just a simple layman when it comes to electronics and i might be better at describing this.

does this make sense? where is granny? lol
I can be true to you sweety until I find a nice medium scale with great breasts. ... CW

chromium

#2
That circuit is a real mind bender!  Outwardly, though, it seems like it will be a blast to use - lotsa different sound options, and not riddled with controls.

The slide switch has two independent layers/wafers/discs - each with identical pin and switching configs.  On that schematic above, I had just added your pin labeling from those switch diagrams that you posted (the numbers labeled in red), and I had arbitrarily labeled the two discs as "disc 1" and "disc 2".  It doesn't really matter which disc ends up being disc1 or 2 - just as long as you remain consistent once you choose.

Here's a view of the actual switch with your pin labeling superimposed:




It's really hard to follow the flow of things looking at that schematic, so I drew up some logical diagrams that will hopefully help demystify the pickup switching a bit.  In these diagrams, the two discs are represented above and below the dotted lines, and the relevant pins on each disc are labeled within the circles.  You can see how the wiring, in some places, hops all over the place just to connect two pickups together.  It's like a sadistic game of connect the dots!   :o   Keep in mind that there are sometimes additional, superfluous connections in a given switch position that are not represented in these diagrams for the sake of clarity.  Those likely come into play in other switch positions.

So - that said, this is how the slide switch would work to wire things up according to the schematic above:


(NOTE: a line from the bridge pickup to pin "4" should be there - it disappears when I post the drawing and it gets resized)






Does that make any better sense of the pickup switching??  It's hard to put into words what is going on there!  I'll do my best to help if you run into any snags when wiring this up.  I'm not really sure about the color coding on the wiring for those pickups - I would probably just let the Ohm-meter do the talking there - see which combination(s) of wires gives you the impedance you are expecting, and go with that.

Barklessdog

Quote from: old puppy on July 03, 2008, 05:13:20 PM
I'm kind of a dummy when it comes to electrifications but it seems there are three constants 3, 7, 11) on your rotary diagram and two (3, 11 but no 7) on your two disc diagram. are you trying to mix apples and oranges with a single disc vs a two disc switch? which makes me ask the question do you need a 3p4t single wafer like a later or early eb3 switch instead of a two disc switch (both are available) which might have different constants even though the later is a 3p4t, but also can carry independent circuits if the third common constant isn't used.

the third circuit would also be the shunt to either coil or cutoff switch for the none loading dummy coil when it isn't needed. I wish i was more than just a simple layman when it comes to electronics and i might be better at describing this.

does this make sense? where is granny? lol

Thanks for the replies!

Thanks for the clarification diagrams Chromium, the diagrams making everything look very simple.

The beauty of the Blueshawk is its inventive switching and dummy coil. That's what I want to recreate directly. When I started looking at the Gibson Schematic, it seemed crazy the way wires go to seeming random places on the switch!

Another Question- How do I wire the Big D varitone to the bypass switch?

The big Big D has two wires that just solder to the input plug only. So I guess I wire the hot wire from the varitone to the push pull bypass switch and the other from the switch to the output jack?

You can see the separate push pull bypass switch in the bottom left hand corner.


chromium

#4
Quote from: Barklessdog on July 04, 2008, 05:54:55 AM
Another Question- How do I wire the Big D varitone to the bypass switch?

The big Big D has two wires that just solder to the input plug only. So I guess I wire the hot wire from the varitone to the push pull bypass switch and the other from the switch to the output jack?

It doesn't necessarily have to wire directly to the jack.  You can also wire it into the circuit in other spots, in place of a  tone control.

In this case, I would wire it in like this - run a wire from the Big-D to the bypass switch, and the other wire to ground:


Barklessdog

thanks I was just not sure where to put the hot on the switch.

About the pickups, i asked at Talkbass and some answered this-

QuoteThe base plate is definitely to be connected to ground. In practice, either one of the other two, but not both will be connected to ground as well. It would only matter which if you have more than one pickup connected, as that would determine if they will be in phase or not.


Should I connect one of the coil wires to ground and if so, do I  need ground the same wires on both pickups.

ramone57

Ripper pups have three wires also (at least mine did).  Mike Dolan told me that one should be ground , one of the other two would be hot the other grounded.  he said it didn't matter which of the two 'hots' went to ground as long as it was the same for each pickup.  otherwise the pups will be out of phase.  it worked out as he said it would.  hope this makes sense to you, I'm not an electronics guy in the least so I probably didn't 'splain it too well.  I'm sure somebody here (Joe?) will be able to give you proper advice.

chromium

Quote from: Barklessdog on July 04, 2008, 10:07:52 AM
Should I connect one of the coil wires to ground and if so, do I  need ground the same wires on both pickups.

In a more conventional circuit you would connect one side to ground, but here you are going to want to connect both leads from the neck and bridge pickups into the appropriate pins of that switch.  The ground changes depending on the switch position.  The only pickup that will actually have a hard/dedicated connection to ground on one side is the dummy coil.

You see how on the original schematic they reference a black and white lead coming from each pickup?  I would just substitute the red lead on your pickup for the black one referenced in the schematic.  And, like Ramone57 said, make sure to stay consistent with this so you don't run into any phase relationship problems between the pickups.

Barklessdog

I wired strung the bass up and did not get any sound except a bad ground humming  (I need to re ground the bridge.

More of a concern is there is a slight bow in the neck that till I get sorted up might mean I might have to sink the Kahler chassis in the body slightly, which I have seen other people do.

I have the truss rod fairly tight and most of the bow gone, but is still slight. I need to get the set right before I try the electronics again. I hind sight I should have got the bass all assembled and playing before I finished it. The down side was milling the Kahler rout, which is tough to fit on our milling machine, so I routed it with the neck not mounted.

I know I can sort things out, but it's going to take some tinkering.

chromium

Sorry to hear about the neck challenges.  Maybe try this trick to help work the bow out?

   http://www.vintageguitars.org.uk/phpBB/viewtopic.php?t=1315&highlight=clamp+neck

When you do get back onto the electronics, post a picture here of the current wiring harness so we can debug it.

Barklessdog

Thanks again, I will try the clamp method. I will keep you posted once I get the neck unbowed and the bridge mounted /finished.

Barklessdog

Tried the neck clamp and it worked really well. It took the bow out without having to over tighten the truss rod.




Barklessdog

Well, I guess we are stonewalled at this point.

Well I tried wiring it, got nothing, took it to my luthier who did not have a clue and finally took it to a reputable guitar repair place in Chicago- They are not getting it to work either.

It's either something with this switch or nobody gets this circuit to make it work.

I talked to my friend who has the Blueshawk Guitar and is an electronic engineer , who said he would wire it, but he lives in Cleveland.

The guitar shop still is trying last I talked to them.



the mojo hobo

Quote from: Barklessdog on July 04, 2008, 10:07:52 AM
thanks I was just not sure where to put the hot on the switch.

About the pickups, i asked at Talkbass and some answered this-


Should I connect one of the coil wires to ground and if so, do I  need ground the same wires on both pickups.


I know I'm late to this party, but it looks to me that the pickups might be wired in series, so one of the coil wires on one pickup goes to ground the other wire goes to the next pickup, and the other wire of the second pickup is the output.

In the schematic all the pickup coil wires go to the switch, except the center one which is grounded, making it look like the switch could be used to switch the pickups from series to parallel.

chromium

Quote from: Barklessdog on July 25, 2008, 05:36:19 AM
Well, I guess we are stonewalled at this point.

Well I tried wiring it, got nothing, took it to my luthier who did not have a clue and finally took it to a reputable guitar repair place in Chicago- They are not getting it to work either.

It's either something with this switch or nobody gets this circuit to make it work.

I talked to my friend who has the Blueshawk Guitar and is an electronic engineer , who said he would wire it, but he lives in Cleveland.

The guitar shop still is trying last I talked to them.


If it is of help, and if you're into shipping the parts abroad, I'd wire it up for you - consider this an open invite.

I figure I could always rig up a quick jig out of cardboard or something to float the pickups over one of my bassses and test everything out, and then you'd only have to hook up the bridge ground and deal with desoldering/resoldering the pickup connections when you get it, in order to route the wires.  Shouldn't cost much to ship just the electronics, and I already have everything to do it (nice push-back wire, etc..) in bulk for my own projects.





Also- with photos, I might be albe to help you debug its current state if you're into trying that.

Hate to see you ditch your plans and compromise for some other setup just because it's kind of a tricky job.