sheepdog
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Post by sheepdog on Aug 29, 2006 12:54:28 GMT -5
I have a PJ bass that I am rewiring volume/blend/tone (instead of vol/vol/tone). I am trying to modify the star grounding instructions I found online to my purposes, but I am having trouble. Anyone have schematics for this? A schematic for any 2 pickup bass wired vol/blend/tone should work. Step 16 from: was the part that really confused me. I can understand the ground lug on the pot going to the common (star) ground, but why would there be a wire from the output jack back to that same ground? There is already a ground to the output jack via the capacitor. I'm trying to get this done. I play bass at my church and my new bass has some hum problems. Thanks!
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Post by UnklMickey on Aug 29, 2006 13:24:40 GMT -5
hi Sheepdog,
welcome to Guitarnuts2.
on the grounding issue:
the capacitor connects the "shielding ground" to the output jack.
that is not the same as the "signal ground" aka star ground.
nothing in the signal ground circuit, should have any direct electrical connection to anything in the shielding ground circuit.
a wire is necessary to make a direct connection from the star ground to the ground terminal of the output jack.
while the shock prevention capacitor COULD be connected to the output jack INSTEAD of to the star ground, i don't think John describes doing it that way.
i think he describes using that capacitor to indirectly connect the shielding and bridge via the star ground junction.
cheers, and i'll leave the blend issue for one of our other members who are better at that.
unk
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sheepdog
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Post by sheepdog on Aug 29, 2006 14:00:28 GMT -5
the shield ground (copper shielding under pickups and in control cavity) is connected to the common ground point via the capacitor. The pickup negatives are attached to the same common ground. The tone pots are grounded through connection to the shielded cavity/pickguard. The volume pot is wired to the same point and then to the negative on the jack. Now the only question is where to ground the blend. Also, do I have to isolate the volume pot to prevent it from being grounded through connection to the pickguard.
I just priced a local guitar shop and his pricing was hideous. If I can get the process down, it is something I can handle.
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Post by UnklMickey on Aug 29, 2006 15:21:36 GMT -5
...Also, do I have to isolate the volume pot to prevent it from being grounded through connection to the pickguard.... not exactly.when i fully answer this question, the rest of what you want to know, will probably become more apparent. you want the case of the pots to still be connected to the shield ground. the stuff inside is not internally connected to the case. most times, one of the 3 terminals is either bent over, and soldered to the case, OR a wire connects one of the terminals to the case. THAT part needs to change.any terminal that was previously connected to the case of the pot, now needs to be connected to the signal ground. unk
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sheepdog
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Post by sheepdog on Aug 29, 2006 16:09:59 GMT -5
my apologies for the rough picture, but I don't have photoshop. only ms paint. does this look correct? the negative tabs on the blend (2 tabs) and tone (1 tab) are wired to the star ground. The negative tab on the volume is wired to star ground and to the negative on the jack I did this fairly quick, so once again...my apologies for it looking like crap
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Post by UnklMickey on Aug 29, 2006 17:20:07 GMT -5
my apologies for the rough picture, but I don't have photoshop. only ms paint. ... hey Sheepdog, Paint ain't so bad, until recently, that what i used for all my Guitarnuts drawings. [EDIT] all the drawings i have posted on Guitarnuts2 [/EDIT] (i've started using TinyCAD (free) and i think it's pretty good.) no sweat on the drawing! you're not posting to the schematics page, you just need to get your point across, and have a map that you can use to check the actual wiring, as you complete it. mostly it looks good. a couple of comments about terminology and particulars. the green wires: blend output, good choice of words. volume input rather than volume output would also be okay. you don't show the string ground. it could be connected anywhere on the shielding. i think i would connect it directly to the "ring on pot" the tone pot will cut the treble when at 10 the way it is wired. if you like it better that way, no problem. most times it's wired for treble cut at zero. to do that, EITHER move the green wire to the far right terminal of the tone pot. OR just move them both to the right by one terminal. the green wire on tone pot can come from the volume pot the way you have shown it. OR it can come from either green terminal of the blend pot. just do that the way it is most convenient for you. in fact, if the tone pot and blend pot are close enough together, you could even connect the tone cap to the green wire of the blend pot, and to either the center or right terminal of the tone pot. in that case, the black wire would go to either the center or right terminal of the tone pot (the one the tone cap isn't connected to.) and the green wire marked "volume output" would not be used at all. the blend pot as shown, will have the precision pair when on 10, and the jazz pickup when on zero. that seems pretty "normal" to me. you probably already know this, but, if you want it the other way, just exchange the red and blue wires. unk
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sheepdog
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Post by sheepdog on Aug 29, 2006 17:44:08 GMT -5
THANKS!
YOU ROCK!
Is that your guitarnuts site? I wasn't sure if that person posted here regularly. If that is your site, GREAT site!
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Post by UnklMickey on Aug 29, 2006 18:00:38 GMT -5
no Sheepdog,
that's John Atchley.
i guess i should have said "all the drawings i have posted on guitarnuts2."
i don't agree with 100% of everything John has said. (heck, i don't even agree with 100% of everything I have said!)
but if you were to confuse me for him, i guess i would be highly flattered.
unk
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sheepdog
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Post by sheepdog on Aug 29, 2006 22:48:13 GMT -5
my original "you rock" comment still stands. i'll post changes to make sure I am on the right track. might even try tinycad.
I figure that others might be interested in this as well since it should work for any passive 2 pickup bass
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Post by UnklMickey on Aug 29, 2006 22:59:15 GMT -5
that would be real nice.
send PMs to JohnH and ChrisK
ask them if they have other ideas for blend pots. (they might know of something, you might like even better than what you have now.)
if/when you work up a neat drawing for your final product, and we check it over, it would make a nice addition to the schematics page.
i'll keep my eyes open for the next draft of the map you'll be working your build from, but i think you have things figured out at this point.
good luck
BTW, the you rock thing, was a nice compliment. thanks.
unk
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sheepdog
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Post by sheepdog on Aug 30, 2006 11:17:05 GMT -5
I modified it based on the post(s). The tone is now reversed (1 is now where highs are rolled off) and the J and P pups are swapped. I wanted 10 to be all J and 1 to be all P. this does seem strange that the tone pot isn't in line between the volume and the jack, but will this still work properly? Blend to choose pickup mix, volume, and passive tone? Wanted to make sure I understood everything properly. thanks for all the help
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Post by UnklMickey on Aug 30, 2006 11:41:32 GMT -5
...this does seem strange that the tone pot isn't in line between the volume and the jack, but will this still work properly? ... hey Sheepdog, that part is just fine. but it seems like you were sleepin' at the wheel when you drew in the wire from the bridge/strings. you have it going to the the star ground. you want it going to the "ring on pot", on the other end of the capacitor. fix that, and you're done. good luck, unk
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sheepdog
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Post by sheepdog on Aug 30, 2006 12:18:44 GMT -5
...this does seem strange that the tone pot isn't in line between the volume and the jack, but will this still work properly? ... you want it going to the "ring on pot", on the other end of the capacitor. fix that, and you're done. good luck, unk I thought one end of the capacitor went to star ground and the other end attached to a ring that you placed on a pot. Does it not go on the pot? Do I attach it to string ground instead? Do I put the ring on the pot and still attach it to the string also? Thanks
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Post by UnklMickey on Aug 30, 2006 12:56:56 GMT -5
lemme see if i can say this so it's not confusing.
one end of the capacitor:
ring connector, pot case, shielding, string ground. all connected together.
other end of capacitor:
star ground.
hope that explains it better.
cheers,
unk
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sheepdog
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Post by sheepdog on Aug 30, 2006 13:31:47 GMT -5
lemme see if i can say this so it's not confusing. one end of the capacitor: ring connector, pot case, shielding, string ground. all connected together. other end of capacitor: star ground. hope that explains it better. cheers, unk forgive my ignorance. It was tough trying to understand all this by translating the guitarnuts site for a bass guitar instead. I understand now
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Post by UnklMickey on Aug 30, 2006 13:47:53 GMT -5
...forgive my ignorance.... and my less than clear descriptions. hey, we got there eventually. no worries. unk
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sheepdog
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Post by sheepdog on Aug 30, 2006 15:19:57 GMT -5
I decided to re-do the picture so it didn't look like a 3 year old drew it and just to make sure we're on the same page. The pots in the picture are being viewed from the bottom (shaft pointing away)
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Post by UnklMickey on Aug 30, 2006 15:48:49 GMT -5
nice drawing.
+1
unk
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sheepdog
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Post by sheepdog on Aug 30, 2006 15:56:58 GMT -5
I didn't want to waste my time being O.C. and A.R. if it wasn't correct.
thanks
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Post by UnklMickey on Aug 30, 2006 16:09:08 GMT -5
i think i know what A.R. is.
O.C.?
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sheepdog
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Post by sheepdog on Aug 30, 2006 16:13:50 GMT -5
i think i know what A.R. is. O.C.? obsessive compulsive (and anal retentive) and a repeat of my question: this wiring is assuming the pots are being viewed from the bottom, not the top...correct?
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Post by UnklMickey on Aug 30, 2006 16:19:54 GMT -5
that must be why i didn't know what OC was.
it sounds too proper and PC
AR, on the other hand, sounds rude and disgusting.
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sheepdog
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Post by sheepdog on Aug 30, 2006 16:27:02 GMT -5
AR, on the other hand, sounds rude and disgusting. it's a curse...I can tend to be both at times.
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sheepdog
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Post by sheepdog on Aug 30, 2006 16:49:20 GMT -5
would this be the appropriate time to move this to the sub-forum for futher review? I wanted to make sure I followed forum protocol
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Post by UnklMickey on Aug 30, 2006 17:54:25 GMT -5
...I wanted to make sure I followed forum protocol i guess there's a first time for everything! the schematics page is reserved for completed designs. posting to the schematics page: 1 -- (required) -- the design has been thoroughly worked out and de-bugged (at least on paper) 2 -- (required) -- a readable drawing. either a pictorial style wiring map, or a schematic (or both). 3 -- (required) -- text explaining what it does, and info on any non-standard components. indicate whether it is has already been built and tested. 4 -- (optional) -- pictures of the finished product. 5 -- (optional) -- sound clips. put together the appropriate text to go with your drawing, and post it. cheers, unk
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sheepdog
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Post by sheepdog on Aug 31, 2006 9:26:11 GMT -5
I'll keep this here for now then. I won't consider the design complete until I have tested it out for myself.
thanks
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Post by JohnH on Aug 31, 2006 19:03:33 GMT -5
Looks good to me. the main thing would be to get a genuine blend pot, one which will give you 100% of both pups at the mid position, with a detent if possible. Also to make sure it is wired the right way round, in terms of which outer lugs go to ground and which to the pups. I havent used these myself, but ChrisK has them on several of his designs.
cheers
John
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Post by ccoleman on Sept 1, 2006 14:27:31 GMT -5
sheepdog.. nice cad drawing.. I should make one or two like that... can I ask, what software did u use, mate ?!
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sheepdog
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Post by sheepdog on Sept 1, 2006 15:59:27 GMT -5
LOL!
thanks for the compliment, but that is nothing more than MS Paint. A lot of patience and liberal use of the erasing feature. I got the pots to look so even by making one pot and then copying/pasting it for the others.
someone here said tinycad, but I didn't have the patience to figure out how to use it. Paint works well enough if I have enough time.
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Post by UnklMickey on Sept 1, 2006 16:14:10 GMT -5
hi Sheepdog,
i did most of my work in Paint.
i've started using TinyCad, and the more i use it, the more i like it.
it has a few quirks, but once you get used to it, you'll find more and more features that make life easier.
JohnH does his drawings in Word.
so, it isn't just about the program, it's about the "artist".
unk
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