toddw
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Post by toddw on Aug 9, 2007 14:28:10 GMT -5
I know, it's probably a silly question, but can caps and resistors in parallel, that aren't gounded, effect a circuit? Here's my idea. I know it's not unique, but if I build this, and am using say switch position 3 as shown (C3 and R3 in parallel across the wiper and bottom of the tone pot, and then to ground through the 1.5h coil), will R2/C2 and R4/C4 effect the circuit even though they aren't grounded? It doesn't seem likely, but I wanted make sure. Thanks, Todd (EDIT: converted URL link to show the image within this post - sumgai)
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Post by sumgai on Aug 9, 2007 15:29:48 GMT -5
Doc, The short answer is no, none of the remaining RC combos will have any effect on the signal. The long answer is...... that's an ambitious circuit there, my friend. But I gotta ask, why did you connect the "bottom" of the tone pot to the switch section that selects the inductor? Seems to me that no matter where the pot is rotated, the selected inductor will remain in the circuit. What you'll have is a pickup (an inductor in itself), a straight resistor (the pot's resistive element), and another inductor, thence ground. The point where the signal is tapped for use is 'above' the pot, true, but nonetheless, the inductor is in the circuit at all times. Is that really what you intend? Worse, if you go for position 1, then the pot is wired directly to ground! That's a Romper Room no-no! I think you're getting most of your information from the "new and improved" Blueshawk diagram. You'll note therein that the tone control is not grounded. Ditto for some of the other Varitone circuits seen both here in the NutzHouse and abroad (around the innerweb). Minor things like 'where's the output' are easily inferred, but for the sake of completeness............ HTH sumgai
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toddw
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Post by toddw on Aug 9, 2007 15:51:03 GMT -5
Hi Sumgai, Doesn't position one act like a standard tone control, putting a variable resistance between a cap and ground? EDIT: Oops. Stupid mistake, would have just decreased my max output. With the other positions, I was trying to do 5 variations of this: homepages.ihug.co.nz/~online/nocaster/blqfilterwiringdrawnbyvito.jpgThought the varitone was an inductor in series with a (cap&resistor parallel), and that in this diagram the q-filter was the inductor. Guessing I was wrong! Todd Edit: OK, searched and read more. Q-filter is cap-inductor in parallel with resistor, so will re-do and re-post.
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toddw
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Post by toddw on Aug 9, 2007 21:20:14 GMT -5
OK, without another deck on the switch, I couldn't have the rotary switch change the notch filter and tone control into an EQ like the one in that schematic. So I decided to simply do something nearly identical to the bluehawk. I think the only thing different is I figured I might as well lower the frequency of the high cut as the notch frequency gets lower. www.geocities.com/trwmdmba/Tone8907.jpgSumgai, If that schematic is reasonable, I need to thank you for saving me from making a mess trying the other one. Oh, I'm planning to put a Bill Lawrence L-609 (formerly L-490s) in the neck position, 3.6h, and a L-600 humbucker (formerly L-450s) 4.8h, at the bridge. Thanks again, Todd edit PS) I may, however, try changing the tone control to an EQ like the one in that link. Not sure how that would work combined with the notch filters though.
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toddw
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Post by toddw on Aug 9, 2007 21:52:35 GMT -5
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Post by sumgai on Aug 10, 2007 0:47:47 GMT -5
Doc, If you'll look at that BluesHawk link, there's a menu across the top of that page that'll show you the circuit diagram. (I didn't direct link to said circuit, I thought the whole of the BluesHawk project might be of interest.) That circuit shows, and so do many others, that indeed, the inductor is in series with the RC combination - you had it right the first time. What you did wrong, IMO, was to connect the bottom terminal of the tone pot to the intersection where the RC combo met the inductor (the common point of switch section B). Simply leave that connection out of the circuit, and what you had really should work. How it'll all sound, that's beyond mortal ken. You want my opinion, both of your latest circuits are overly complicated. I suggest, as mildly as possible, that you start with one RC combo in series with one inductor. Don't attempt this early in the game to outfox Mother Nature - your ears will play tricks on you! The goal is to simply make sure that you can indeed make an RCL combination work. Once that's done, it's time to experiment by duplicating the layout, with differing component values. Again, the KISS principle applies - change just one thing at a time, as you go through the stack (a stack being your five "non-standard" positions). I'd start with the caps, varying them as you've suggested in your diagram. When you're relatively happy, then experiment with the inductors. Then the resistors, they should be last because they'll have the least effect (given your foreshortened range of chosen values). Only if all of this sounds absolutely terrible, that's when you consider going to Plan B. (A different layout.) In summary, all the preparation with a calculator and formulas and such, that's a good thing. But when the rubber hits the road, only some good old-fashioned breadboarding will give you the information that you need to know about which way to go in terms of component values and such. Fortunately, you can do this without having to spend oodles of time inside your axe..... simply run some long co-ax (shielded) cable out from the selector switch to your work bench, and have at it! ;D HTH sumgai p.s. Did you catch any fish?
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toddw
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Post by toddw on Aug 13, 2007 11:47:17 GMT -5
kiss principle? KISS PRINCIPLE!? Who you callin stoopid ? ? . . . We didn't catch any fish, but the wind was so low for a lot of the trip that we probably should have brought rods along and tried. As to the schematics, I didn't really think the later circuits were more complicated. When I drew them I was thinking that being able to cut some of the highs above the notch filter might be nice, and I'll make up an eyelet board, so wiring will be easy. But given I never use the tone control on my guitar, maybe I will stick with the first one. Without the wiring error of course. Todd
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