greybagz
Apprentice Shielder
Posts: 41
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Post by greybagz on Jun 19, 2007 2:44:29 GMT -5
Hi Everyone, Thanks for reading my post. I was wondering if anyone knows what type of tone pot, or what the unit on the back of my 500k tone pot does. It is installed in my Epiphone Nighthawk, it has been in the closet far too long and I was going to attack the wiring when i first bought it secondhand, but never got around to it. It has never sounded quite right, I've drawn a draft of the wiring and by what I can make of it (only a basic idea), Its no wonder it sounds terrible. I would like to post a diagram of the wiring so someone could confirm my assumption and point me in the right direction, but wasn't sure how to. What program do most of you use to draw your wiring diagrams?, there is some really neat ones within the forum and I really don't think you need to be exposed to my chook scratch on paper. Thanks for your time. Graeme
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Post by JohnH on Jun 19, 2007 5:26:19 GMT -5
greybagz - lets see if the Americans know what a chook scratch is.
I do my diagrams in Word, making a screen print when they are done and saving as a gif, or you can use any graphics or CAD program. A scanned hand sketch is fine too'
Clearly you have image posting figured out
I dont know what that pot does, but I do know is that I definately need one.
John
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greybagz
Apprentice Shielder
Posts: 41
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Post by greybagz on Jun 19, 2007 6:35:29 GMT -5
Hey John, I threw it in there to see if anyone knows about the chook scratch (maybe just an Aussie thing). Thanks for the tips on diagram drawing, I'll get on it. In regards to the pot, here's a couple more photos. You may notice that the only physical connection to the pot from the device on top, is 2 solder joints to the case of the pot to hold it on, there is no mechanical parts. Seems to be a normal A500k mini pot with an upgrade/ mod. Electrically though, A .47? cap is connected to pot case and then to a wire of unit, then on other side a wire from unit is connected to 5 way switch output (correct terms??). Whether this is correct wiring is what I hope to discover. If it has a purpose it will stay, If not I'm happy to remove it and just have a normal 500k tone pot. Just interesting I suppose. Thanks again. I hope not to be too long with a wiring diagram to help.
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Post by UnklMickey on Jun 19, 2007 7:50:59 GMT -5
greybagz - lets see if the Americans know what a chook scratch is. hmmm? context: drawing. apparently he thinks the drawing isn't great. ...maybe chook scratch = chicken scratching?
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reeced
Rookie Solder Flinger
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Post by reeced on Jun 19, 2007 9:21:03 GMT -5
I think it's an inductor, used as a midrange boost/cut in conjunction with the cap and the pot.
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Post by ChrisK on Jun 19, 2007 11:46:29 GMT -5
It is indeed a series resonant LC circuit. One end is connected to the pot case and presumed grounded and the other goes somewhere. Connected to ground, this would act as a notch filter.
This would be similar to a Varatone at one setting.
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greybagz
Apprentice Shielder
Posts: 41
Likes: 0
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Post by greybagz on Jun 23, 2007 2:46:49 GMT -5
Hi All, Sorry about the delay, Been busy at work and home. I've finally got a drawing for you. Hope it can help. From what I can follow (good at following bridging on distribution powerlines and switchgear, not so up to speed on guitar inards, but here we go), Please tell me if I'm wrong: With dpdt switch in postion 1 5way position 1) N (south only) 2) N south +M 3) M 4) M + B south 5) B south only With dpdt switch in postion 2 5way position 1) nothing 2) N Full HB 3) N Full HB 4) N + B (Both full hb) 5) B Full HB Please tell me if I'm way off, I'm not too good at understanding the flow of things inside. But I know I've definately got no sound at DPDT postion 2 / 5way pos 1. Any ideas for correction and a much better sound? It just doesn't seem right to me. Oh, and that varatone thingy? Does it serve a purpose in here, if so how and where? Again thanks for your time. Yes Unk ur right about chook scratch, my freehand is not the best. Graeme
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Post by michaelcbell on Jun 23, 2007 21:35:13 GMT -5
Ok, can you clarify for me what the 5-way is doing in each position as it doesn't seem standard and the circuit board switches that look a bit more like your diagram come in different flavors...
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greybagz
Apprentice Shielder
Posts: 41
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Post by greybagz on Jun 24, 2007 2:53:06 GMT -5
Hi Michael, I'll try my best to answer ur question. I hope not to confuse anyone by using incorrect terminology as I'm not too up to speed with it, but I am sure learning a bit from this site THX. I hope the diagram is better and explains the 5 way for you, is that what u were asking? I do understand why you say it doesn't seem standard, the wiring is all over the place, hence me trying to correct it. I can ony speak of how i understand it but the Dpdt switch works by one side of it been on and the other side off, vice versa when switched to other postion, correct? I can't reference any pickup sound at the moment as the guitar is in pieces, I'm having the headstock repaired. Reading this makes me seem simple minded, with a lack of explanation skills, so please let me know if I've answered your question fully. I do appreciate ur help. Does anyone have any ideas of maybe just disconnecting all wires and starting again using the components I have? 5way switch, 1 x 500k Vol, 1 x 500k Tone and DPDT switch. Original reviews of the nighthawk say that its setup was MiniHb in the neck, single coil in the middle and HB in the bridge with coil tap. Pickups are the Korean copies of the Gibson OBL range. Neck being a shielded mini humbucker, middle a single coil, and bridge a slanted humbucker. I think I've blabbed enough for now. You guys are great, I'm enjoying reading ur posts from past and present. Graeme
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Post by michaelcbell on Jun 25, 2007 6:48:05 GMT -5
Graeme,
I looked through the diagram you gave and in positions 1, 3, and 5, all is well. In 2 and 4, however, all hell breaks loose.
Key: + means combined in parallel, x means combined in series "Humbucker" means both coils in series. With your DPDT in position 1: 1- Neck South only 2- Neck South + Mid + Neck North out of Phase 3- Mid 4- Mid + Bridge South + (Bridge North Out of Phase x Neck Humbucker) 5- Bridge South
With your DPDT in position 2: 1- Nothing 2- Nothing (short to ground) 3- Neck Humbucker 4- both Neck and Bridge (humbuckers) 5- Bridge Humbucker
As you see, positions 2 and 4 are a little scary. You can eliminate the dead position in pos 2 by removing the groudning wire from lug 1, bottom half of the 5-way. That will make DPDT position 1, 5-way position 2 'fixed' to Neck south only + Mid, but it won't fix position 4.
In general, I feel that what tones you thought you had are all very good tones, and could be accomplished with the components you have (maybe), but I'd want to eliminate dead spots and hanging hots (the latter may not be entirely possible). Another thought would be to try series combinations, but that would mean more switches in my opinion. What are your thoughts?
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