pk317
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Post by pk317 on May 16, 2022 9:33:04 GMT -5
Hi guys,
I have a guitar with HS configuration, one volume, one tone. I had 500k volume pot installed, HB was fine, but SC was way too bright. I changed it to 250k pot, and now HB is darker than I like, and SC is still too bright. Then I thought to put a grounded resistor to SC switch lug, so it will see, let’s say 150k pot, and HB will still see 500K. And then I thought maybe to put a grounded capacitor to SC switch lug, so it will be like constantly rolled off tone knob. The result, as I can see, in both cases is the same, to take off extra brightness from SC. I’m not sure, though, that I am 100% correct here, so would appreciate to hear your opinions.
1. What is the result of these two approaches? Any difference from technical/sound perspective?
2. How would you calculate the value of the resistor? Let’s say, to turn 500k pot into 150k, should I just put a resistor of 350k, or is it more complicated?
3. Is there any other way to make SC darker without adding second volume knob?
Thank you.
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Post by newey on May 16, 2022 11:30:38 GMT -5
Well, the resistor to ground will cut all frequencies, while the cap will just cut the highs, depending on the values you choose. You can experiment with values for both external to the guitar, so you can try different values without needing to open up the guitar each time.
But a better solution is to use a dual-gang pot, with one gang at 500K and one at 250K. These do exist, they may be a bit tricky to find, but that way you can wire the HB to 5OOK and 250K for the SC.
What value is the tone pot? If that is also 500K, consider changing that to 250K, might be a workable compromise.
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Post by Deleted on May 16, 2022 11:31:59 GMT -5
Hmm
Well I could suggest dual Stack 500K pot. That when all lugs linked to its counterpart reduce it down to 250K
I guess depends on the switch lay out.
I did think a capacitor (bleed) makes some thing more brighter
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Post by thetragichero on May 16, 2022 12:30:39 GMT -5
dual gang 500kA pot with a 470k resistor across the outside lugs of the pot used for the single coil. might still be a bit bright with a 500k tone pot but you could always do the same thing for that
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Post by unreg on May 16, 2022 18:24:59 GMT -5
2. How would you calculate the value of the resistor? Let’s say, to turn 500k pot into 150k, should I just put a resistor of 350k, or is it more complicated? It’s more complicated… can’t find the math now, sry. But, it is wise to drop your 500K Tone pot to 250K by adding two 1Meg resistors soldered in parallel between the outer lugs of your 500K Tone pot, before switching the pot out. That way, you can see roughly how the 250K Tone pot would sound. “Roughly”, bc while the 10 setting will definitely be the same as a 250K Tone pot, a new 250K pot’s taper will be different. 3. Is there any other way to make SC darker without adding second volume knob? , it’s quite easy to reduce treble by slightly turning the knob down (like at a 9.9 Vol setting). This helps me tons with my humbucker that acts like a single coil.
EDIT: My “wise” is not really absolute. While soldering those two 1 Meg resistors in parallel between a 500K pot’s outer lugs does reduce the pot to 250K, the process of soldering two resistors in parallel between its outer lugs leaves little room for other wires on lug1. And that process probably requires pot removal, so I guess if you haven’t already bought another 250K pot, you could possibly save money with the resistor purchase. Though, I was encouraged to switch my 500K Tone pot for a new 250K pot, since I loved the 250K change. The changed taper, brought by the new 250K pot, works so much better for me. |
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Post by reTrEaD on May 16, 2022 19:56:20 GMT -5
I had 500k volume pot installed, HB was fine, but SC was way too bright. I changed it to 250k pot, and now HB is darker than I like, and SC is still too bright. Okay, so the loading with the 250k wasn't enough to tame down the SC and it threw a blanket over the HB. So you need a more targeted approach. The concept of having a fixed resistor in parallel with the SC connection is valid. And of course, you'll need a lower value than two 1 Meg resistors would give you. That would only achieve the results of the 250k volume which still left the SC too bright. How would you calculate the value of the resistor? Let’s say, to turn 500k pot into 150k, should I just put a resistor of 350k, or is it more complicated? . And lets use some commonly available values for the fixed resistor. 330k x 500k / (330k + 500k) = 199k 270k x 500k / (270k + 500k) = 175k 220k x 500k / (220k + 500k) = 152k 180k x 500k / (180k + 500k) = 132k 150k x 500k / (150k + 500k) = 115k
Maybe start with a 220k resistor and see how that sounds with your SC alone (and in combination with the HB). Season to taste. |
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pk317
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Post by pk317 on May 17, 2022 8:39:21 GMT -5
Thank you all for the answers! newey, tone pot is 500k, will try 250k as well @angellahash, I think this is correct if you wire it in series, I do it when I need a bass cut on the guitar. If you ground it, it takes the brightness away. At least, that's my experience thetragichero, basically, I could use dual gang pot for tone as well, and then it would be 250k for SC and 500k for HB unreg, will try 250k as well, have some used spares from old guitars reTrEaD, thanks for the calculation, I'll try that out. I once wired a rotary switch to try out different capacitors value for tone cut and bass cut, will do the same with resistors. Sounds like interesting experiment    |
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Post by newey on May 17, 2022 10:55:20 GMT -5
I once wired a rotary switch to try out different capacitors value for tone cut and bass cut, will do the same with resistors. Sounds like interesting experiment You can make a "cap substitution box" (or resistors) for testing external to the guitar, pretty similar to what you did. Can use a rotary, or just use alligator clips to change out the various caps. I don't know how much you use your tone control, if you're not using it often with the bridge pickup, another option would be to just lose the tone control for the HB, use a 250K tone pot for the SC w/ a 500K volume pot for both pickups. This would tame the SC and allow for the brighter HB when the bridge is selected by itself. When both pickups are selected, however, then both V and T pots are in parallel so the lower resistance of the V/T pots together will affect the bridge pickup as well. |
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pk317
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Post by pk317 on May 17, 2022 14:17:02 GMT -5
I once wired a rotary switch to try out different capacitors value for tone cut and bass cut, will do the same with resistors. Sounds like interesting experiment You can make a "cap substitution box" (or resistors) for testing external to the guitar, pretty similar to what you did. Can use a rotary, or just use alligator clips to change out the various caps. I don't know how much you use your tone control, if you're not using it often with the bridge pickup, another option would be to just lose the tone control for the HB, use a 250K tone pot for the SC w/ a 500K volume pot for both pickups. This would tame the SC and allow for the brighter HB when the bridge is selected by itself. When both pickups are selected, however, then both V and T pots are in parallel so the lower resistance of the V/T pots together will affect the bridge pickup as well. Sounds interesting, will try this one as well, thanks! |
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Post by Yogi B on May 17, 2022 16:12:43 GMT -5
But a better solution is to use a dual-gang pot, with one gang at 500K and one at 250K. These do exist, they may be a bit tricky to find, but that way you can wire the HB to 500K and 250K for the SC. There's a couple of things to be aware of if going the dual-gang route. Firstly, with mismatched gangs you'll get a differing mix of the two pickups when reducing the volume compared to using a single gang. For example, if we consider the pot turned to half of its maximum resistance (around 75% on a typical log pot): the lower halves of each pot are at 250k & 125k in parallel which is 83k, so the single coil sees a voltage divider of 83k/(125k+83k) = 0.4, whereas for the humbucker we have 83k/(83k+250k) = 0.25. In actuality it's not quite that simple because we're also affecting the way the pickups load each other, and (assuming the HB has a larger impedance than the single coil) that will somewhat counteract this effect. (It's worth noting that the HSS American Pro Strat is wired like this, and I've not heard any anecdotes about the volume control behaving oddly in position 2 — any change in timbre likely being overshadowed by the overall reduction in volume.) The other thing is that any dual-gang volume paired with a single-gang master tone forces '50s wiring to be employed, which is likely undesirable. Therefore, ideally the tone should be a second dual-gang pot — the two 250k gangs for the SC and the two 500k gangs for the HB hopefully further helping to lessen the disparity between the pickups. |
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Post by JohnH on May 17, 2022 17:41:35 GMT -5
I think , as already discussed,the easiest way to trim the treble on one pickup, in every setting where it's used, is to hard-wire a small cap or a resistor across the leads of the pickup. Then use pots that sound good for the other pickup being the humbucker.
At full volume, you can experiment outside of the guitar, by unscrewing the jack barrel of the guitar cord and use alligator clips. This won't properly represent the setting where you wire it internally and turn down the volume, but it should work at full volume to test. I'd suggest likely cap values say 680pF, 1000pF, 1500pF and 2200pF (which should make a big difference), or if resistors, try 470k, 330k, 220k, 150k. They are all small and cost a few cents only.
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Post by thetragichero on May 17, 2022 19:09:51 GMT -5
now that you mention it my guild jazzbox came from the factory with a cap across the pickup. had wondered why i could never squeeze enough treble out of it
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pk317
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Post by pk317 on Aug 21, 2022 15:56:15 GMT -5
Short update - in the end I just installed on-on switch with capacitor that acts like a fixed value tone knob. But somehow the bright neck SC sound grew on me, it is great tone for leads, so I barely use this switch now  |
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Post by newey on Aug 21, 2022 19:44:59 GMT -5
But somehow the bright neck SC sound grew on me, it is great tone for leads, so I barely use this switch now I'm with you, you can always decrease the highs but you can't add what wasn't there in the first place. Too bright at one point? Use the tone control. But you've "got bright if you want it" to paraphrase Slim Harpo . . . |
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Post by gckelloch on Aug 21, 2022 22:47:01 GMT -5
Short update - in the end I just installed on-on switch with capacitor that acts like a fixed value tone knob. But somehow the bright neck SC sound grew on me, it is great tone for leads, so I barely use this switch now You might find the switch more useful with a low cap value on it. I'd try 1.5~2nF, assuming it's a ~2.5H pickup. The goal is to get a boost in the 2~2.5kHz region. I have that on a few guitars. It might be too strong with the 500k pot -- perhaps over 6dB. You can add a 250~500k R in parallel to tame it. |
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pk317
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Post by pk317 on Aug 30, 2022 15:21:41 GMT -5
But somehow the bright neck SC sound grew on me, it is great tone for leads, so I barely use this switch now I'm with you, you can always decrease the highs but you can't add what wasn't there in the first place. Too bright at one point? Use the tone control. But you've "got bright if you want it" to paraphrase Slim Harpo . . . You're totally right, I just somehow always was in the opinion that neck should be warm. It took time for me to readjust Short update - in the end I just installed on-on switch with capacitor that acts like a fixed value tone knob. But somehow the bright neck SC sound grew on me, it is great tone for leads, so I barely use this switch now You might find the switch more useful with a low cap value on it. I'd try 1.5~2nF, assuming it's a ~2.5H pickup. The goal is to get a boost in the 2~2.5kHz region. I have that on a few guitars. It might be too strong with the 500k pot -- perhaps over 6dB. You can add a 250~500k R in parallel to tame it. I've experimented with different values. Honestly, don't remember exactly what I put there (yeah, definitely should have written it down), but it's something like 0,33-0,56 nF. It really takes out only a tiny bit of high end. |
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Post by gckelloch on Aug 30, 2022 18:22:27 GMT -5
I'm with you, you can always decrease the highs but you can't add what wasn't there in the first place. Too bright at one point? Use the tone control. But you've "got bright if you want it" to paraphrase Slim Harpo . . . You're totally right, I just somehow always was in the opinion that neck should be warm. It took time for me to readjust You might find the switch more useful with a low cap value on it. I'd try 1.5~2nF, assuming it's a ~2.5H pickup. The goal is to get a boost in the 2~2.5kHz region. I have that on a few guitars. It might be too strong with the 500k pot -- perhaps over 6dB. You can add a 250~500k R in parallel to tame it. I've experimented with different values. Honestly, don't remember exactly what I put there (yeah, definitely should have written it down), but it's something like 0,33-0,56 nF. It really takes out only a tiny bit of high end. o.33-0.56nF would be 330-560pF. I'd try the value range I suggested when you get a chance. |
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Post by ashcatlt on Sept 2, 2022 21:07:36 GMT -5
Well, the resistor to ground will cut all frequencies, while the cap will just cut the highs... You'd have to use a pretty darn small resistor to get much broadband attenuation, and it would probably be way too dark before that point. Remember that most of the action of the tone pot is actually just that as you turn it down, the resistance parallel to the pickups gets smaller. The cap is almost just there to stop it from going to silence when it's all the way down. Except when the resistance of the tone pot gets small so that the capacitor is more directly connected to the inductance, you start to get resonance near the cutoff frequency because of imaginary numbers and vector math and stuff. |
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