dogman72
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Post by dogman72 on Apr 1, 2015 12:47:44 GMT -5
New guy here, I bought a basket case, Does anyone have a layout for 2 P-90 with 2 DPDt a vol. and tone.. I had a diagram but I misplaced it.. Any help would be appreciated... Thanks Joe
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Post by haydukej on Apr 1, 2015 15:09:33 GMT -5
Dr. Dog, Welcome. Sorry I don't have the "official" welcoming sign for you.
I'll throw out the preliminary question that would likely get asked from anyone else looking into this before we direct you to a diagram.
Do you have a desired purpose for the 2 DPDTs? Assumptions would lead to series/parallel switching and perhaps a phase switch, but just wanted to make sure. Also, does this guitar have a pickup switch already (i.e. to switch between one or both of the pickups)?
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Post by newey on Apr 1, 2015 19:48:27 GMT -5
dm72-
Semi-officially . . .
Hello and Welcome to G-Nutz2!
Your title, "Wiring help", is a trifle generic. And haydukej is right, we'll need a bit more info. I was sort of assuming the DPDts were the pickup switching.
(If so, the so-called "binary tree" switching scheme would give you either pickup alone, both together in parallel, and both in series.)
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dogman72
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Post by dogman72 on Apr 2, 2015 13:51:41 GMT -5
Thank you for the response, The guitar is a 75 Teisco with a Harmony neck. When I bought it, it had the face plate with the vol. and tone ctrls.. It had the cutouts for the DPDT two in total. I added the P-90s and purchased the two switch's. I was able to find a diagram, but for the life of me I can not find it. I have found an old diagram but the switch's are not the same... Thanks for the welcome.... Joe
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dogman72
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Post by dogman72 on Apr 2, 2015 16:20:25 GMT -5
Just some more info on my wiring. What I have is a Teisco ET-200, I did find a diagram on this board, It shows the switch's with a single row of terminals. I could not find the identical switch's so the ones I have, have dual terminals. Thanks for any help...Joe
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Post by haydukej on Apr 2, 2015 17:11:57 GMT -5
Dog, You can thank Newey for starting this very applicable thread for the Teisco ET 200 wiring and your questions. The diagram on there has the stock SPDT switches vs. your DPDT switches. Assuming your P90s are 2 conductor pickups (2 wires coming out of them) you can disregard the "green" wires on the diagram. As for your DPDT switches, Wolf and John H have you covered. Check out Wolf's 4 post on that thread or JohnH's below it. Coil A will be your neck pickup and Coil B will be the Bridge pickup. let us know if it's still clear as mud.
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dogman72
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Post by dogman72 on Apr 2, 2015 19:58:19 GMT -5
Thanks for the help, I did find those posts and they helped a lot.... Joe
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Post by newey on Apr 2, 2015 21:48:07 GMT -5
Ah, yes the Teisco Tulip.
JohnH's tip on using the DPDT switches to avoid the "hanging from hot" issue is a good suggestion, you might as well do that. The hanging coil has the (theoretical) possibility to generate noise, it may not do so, but the clean way to do it is to eliminate the possibility. And you can, since you already have the switches.
Or, do as I suggested in the Teisco thread and use the full "binary tree" scheme, which eliminates the "all off" setting of the stock Teisco wiring and replaces it with both pickups in parallel (Note that Teisco's stock wiring had the pickups wired in series, whereas the 2 P-90s in parallel will yield a sound more like a P-90 LP).
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nikogo
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Post by nikogo on Apr 3, 2015 8:12:20 GMT -5
I completely agree that while having two DPDT switches it is a good choice to use the JohnH's "non-hot-hanging" schematics. But is it really any problem in having hot-hanging pickup? It is anyway connected to ground through the second pickup with impedance no more than 10K that reduces the circuit's sensitivity. Also the second pickup generates its own hum that will mask a potential noise from a "hot-hanger". I use that type of schematics in my guitars. Tonight I was trying to hear any difference between single coils with and without a "hot-hanger" and failed.
Regarding suggested schematics I have another question. Why the tone control is connected after the volume control? As I understand, the tone control before the volume pot would keep tone more stable when changing volume. Don't you think that the level of volume control can change the filtering through R-RC filter by changing the first R?
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Post by haydukej on Apr 3, 2015 10:01:44 GMT -5
Nikogo, I really can't add anything insightful for the "hanging from hot" portion of your questions, although I think it's one of those topics that some people wish to address while others don't get hung up on it so much Your second question of which comes first, the Volume (V) or the Tone (T), is another that ultimately goes to personal preference. You are correct in that having "modern" wiring ala T before V will produce more "stable" tones while adjusting volumes. However, so people have a preference for the "mojo" delivered by the "50's Wiring" ala V before T. JohnH has modeled the differences and others have contributed discussing this topic in depth on this thread.
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nikogo
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Post by nikogo on Apr 3, 2015 11:03:22 GMT -5
Thank you Haydukej. Very interesting thread with some historical details that confirms my intuitive understanding.
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Post by newey on Apr 3, 2015 11:23:53 GMT -5
nikogo-
To be precise (I knew what you meant but others reading it may not) the second pickup doesn't "generate its own hum", it picks up noise from the environment and transmits it through the amp.
As to the tone controls, the diagram is from the original Teisco wiring from the 1960s, that's the way they did it back then. Certainly, one can wire it to the "modern" wiring with the volume before the tone and avoid the interaction issues. It really comes down to whether one wishes to maintain it completely stock or not.
As to whether a hanging coil generates noise or not, it may well make no real-world difference. OTOH, it might become an issue in a specific environment that suffered from lots of generators of electrical noise- lots of CRTS, florescent tubes, etc. The electrical theory that a hanging coil could pick up noise seems sound, so as a "best practice" it seems best to avoid it where possible. But there are some wiring schemes where it is unavoidable, and those schemes have been built by our members here on numerous occasions without reported problems.
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Post by sumgai on Apr 3, 2015 12:04:33 GMT -5
doggie, Here's the other semi- of the official act: Hi, and to the NutzHouse! You've got some options here, and unless you have already developed a strong preference, then I suggest that you try it both ways - binary switching to give all four possibilities, or standard switching with an off position, in whatever order you deem best. The only advantage I see to an "off" position is acting as a kill switch during a performance. But in a situation like yours, where the switch is not spring-loaded, you are applying force in both directions, not just one. That tends to lead to early switch failure. And yes, some folks like to mute their guitars when they set them down for an intermission, but I feel that turning down the Volume pot all the way down is just as effective, where there's no switch dedicated to this purpose. Where you have binary switching, you have 4 out of the 6 possible combos, meaning either pup alone, both in series or both in parallel. The remaining possible combos are series or parallel Out-of-Phase, or as we call it, OoP. (Further, just to dot the i's and cross the t's, you may run across those designation as Soop and Poop, especially where both are available to the player.) You can obtain those OoP setting with an addition switch, located on your axe as either an additional DPDT toggle, or a Push-Pull switch under one of the pot controls. HTH, and Good Luck!
nikogo, In the matter of hanging hots.... (Which may apply to dogman too, so I'm answering in fuller detail than just referencing a link...) Years ago when this topic first came up, John did some experimenting, I believe you've been referenced to that link already. But that was in a fairly pristine environment, not in a real-world scenario whereby the guitarist is much more likely to encounter undesired electrical interference (aka, hum). Perusing these forums, you'll come across a posting about once or twice a year whereby someone is pulling his hair out by the roots because of his humming guitar, one that hums even in his home. But while most of us enjoy fairly quiet home environments, those of us that play out (in bars, at outdoor venues, etc.) are only too happy to relate horrifying experiences with hum - even in those guitars that were dead quiet at home. This is why newey said "best to just take care of the possible problem, and be done with it". I certainly would not be the first person to say "you can't take a cheapie Tiesco guitar out to play at a public performance", because if that's how you get your tone, then who cares what the brand name is on the headstock. But for certain, if the wiring is not up to snuff, then there'll be tears before the end of the day/night, no matter if the guitar is either cheap or expensive. IMO, there's no good reason not to just do it - it only takes one wire, and a few more seconds of soldering time, and you're one step closer to achieving the right side of the difference between "Oh boy", and "Oh crap".
And now that I think back on it, we're talking about P90's here, yes? Then why hasn't the term RWRP been spoken of yet? dogman, if you procured these as a set of intended Neck and Bridge units, then you're probably not gonna be sweating the little stuff here. But, if you "found" these things individually, then you want to make sure that they are 'reverse wiring, reverse polarity', one compared to the other. See various links around here for more info on that particular topic. HTH, again sumgai
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nikogo
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Post by nikogo on Apr 3, 2015 12:57:05 GMT -5
Yes, Sumgai, I am perfectionist too . And I remember playing under radio station when we were afraid to stop because in pause the Voice of America or BBC was sounding a few db lower from our amps . The question is: would hanging from hot pickup pick anything comparable to the working in the same circuit pickup under any condition?
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dogman72
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Post by dogman72 on Apr 3, 2015 17:04:34 GMT -5
Thanks for all the help, I rechecked the wiring I did and found the wire off the second switch going to ground, I moved and soldered the lead to the correct position.. This thing sounds great!! Thanks again...Joe
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