|
Post by dannyhill on Apr 9, 2013 5:16:50 GMT -5
Hi guys,
Here's a quick one. two regular tele pups in parallel, only the bridge has a 0.0033uF cap across it and another from its ground side to the ground. The neck pup is in parallel with all of this. How would you describe this sound? I heard a sound clip and it sounded like a neck with less highs and lows plus slightly less lower mids. Kind of like a bridge and neck in series but with single pup loudness and less bottom end and more upper mid end.
I guess this really, comes back to the question, how do two pickups combine electrically in parallel? I always thought differences are amplified. Did I ask this before? Still haven't got my head around it. Cheers,
Danny Daniel
|
|
Deleted
Deleted Member
Posts: 0
Likes:
|
Post by Deleted on Apr 9, 2013 5:34:27 GMT -5
Can you give a rough diagram? I do not have a tele, only thing i can tell here is that 0.0033uF is a small-ish value. To give you an idea, in my aria strat with bridge connected to a 0.013uF the sound with tone to 1 still has some sparkle in it. 0.0033uF IMO might not roll off enough treble. Just remember that connecting capacitors in series actually decreases the total capacitance (1/C1 + 1/C2 = 1/C), and that in parallel the reverse is true (C1+C2=C).
|
|
|
Post by JohnH on Apr 9, 2013 15:31:23 GMT -5
It might sound like this.... The caps C6 and C7 that you suggest as 3.3nF are swept from very small, up to 15nF, so the red highlighted trace is close to your suggestion, and the one at the right effectively disconnects one pup so it is a single coil sound, for reference. So it does look a lot like a series type of sound, but at a single volume. But could probably get almost the same result just by ading a cap across one pup. John
|
|
|
Post by dannyhill on Apr 9, 2013 16:10:55 GMT -5
Hi John, 5Spice is our friend. What I had in mind was the following: Is that what you modelled? The great thing is that the caps can be different. On rolls off just the LH pup treble and then its bass and then combines the resultant with the other pup? Or is it much more 'interactive' than that? Cheers, Daniel
|
|
|
Post by JohnH on Apr 9, 2013 22:19:11 GMT -5
My model is the same tonally, but upside down for better grounding of the second pup, for less noise
|
|
|
Post by sumgai on Apr 10, 2013 1:25:11 GMT -5
On[e] rolls off just the LH pup treble and then its bass and then combines the resultant with the other pup? Or is it much more 'interactive' than that? Yes it is much more interactive that you first imagined. For the sake of clarity in the following example, look at your drawing, and in your minds' eye, remove the LH pup. Now, what's left? Answer: two caps in series, both in parallel with the RH pup. What's the effect on the tone of that remaining pup? It also loses some treble. This isn't quite so bad as you might first think, because as previously noted, two caps in series reduces the total value, so the net effect on the tone is less than if there had been only one cap in your circuit. Be aware that as you change from one pup to the other, or to the combination, you might find yourself going from a full, robust tone to a very nasal sounding tone. You may also have to play with the Master Vol and Tone knobs as you go from one to another selection. Just sayin'. HTH sumgai
|
|
|
Post by dannyhill on Apr 10, 2013 3:45:05 GMT -5
You're Sumgai!
The idea was to create a very middy tone from the two pups. The wiring I have also allows the lower cap in parallel with one of them which makes it very bassy.
What I have to say is that 0.01 with 0.0047 did not sound the same as 0.0068 with 0.0056 even though they both provide between 0.0031 and 0.0032. Doubt 0.022 and 0.0033 will provide same sound at a combined 0.0029
Cheers,
Danny
|
|
|
Post by ashcatlt on Apr 10, 2013 9:42:51 GMT -5
Oh it'll probably be nasal. You know, I think my Rick will do something like that, though the cap values are a bit different. I'll have to look into it...
Couple things on John's graph:
1) He's got both pickups exactly the same. Like, to a point of precision that you would only get out of a factory on accident. They are "wound" exactly the same and are both putting out the same amount of energy.
2) The signal being "picked up" is exactly the same for both pickups, and perfectly in phase between the two. The closest you'll get in the real world is maybe two coils of a SC-sized humbucker.
3) All this to say that the graph above show the frequency response of the filter created by the pickup network. It answers the question of what happens electronically, but doesn't necessarily tell you what you'll actually get out of it. If this is between a neck and a Bridfe pickup, they will each be contributing a significantly different signal in terms of harmonic content, and likely at different overall levels. Those signals get mixed, with all of the positive and negative reinforcement from the phase differences at different harmonics, and the that signal is affected by the filter curve as shown.
4) Since both signals are the same, they add to somewhere close to +6db where neither is affected by the filter. On the red line it looks like the bridge pickup is contributing nothing up to about 1KHz. Not only are the lower frequencies noticeably attenuated, but they're all coming from the neck pickup. Or at least that's my read on it.
Don't know if any of this helps...
|
|
|
Post by dannyhill on Jun 7, 2013 15:46:44 GMT -5
Hi John,
Sorry for this reply on this old thread. I just saw that you mentioned the cap being 'behind' the pup as being noisier than if it was 'in front'. Is there really any noticeable difference in an AC circuit, or just on switching? May have to re-design all my circuits :-o Cheers,
Daniel
|
|
|
Post by JohnH on Jun 7, 2013 18:05:23 GMT -5
Hi John, Sorry for this reply on this old thread. I just saw that you mentioned the cap being 'behind' the pup as being noisier than if it was 'in front'. Is there really any noticeable difference in an AC circuit, or just on switching? May have to re-design all my circuits :-o Cheers, Daniel Hi Danny - I'm not quite relating that to my posts. Do you have one of your circuits that you are thinking of there?
|
|
|
Post by dannyhill on Jun 8, 2013 7:29:53 GMT -5
Hi John,
Your comment in this thread, same page:
Apr 10, 2013 at 5:19am Quote Post Options Post by JohnH on Apr 10, 2013 at 5:19am My model is the same tonally, but upside down for better grounding of the second pup, for less noise
|
|
|
Post by JohnH on Jun 9, 2013 15:44:11 GMT -5
OK, The difference is not to do with switching or tone or a/c theory. Its just that the nearer to ground you can put pickup coils, and hence the less they 'hang from hot', the slightly less buzz they might pick up due to stray elecrical signals from fluoro lights etc. Its a small point and not very significantm but given a choice, its better that way IMO.
Taking the circuit in this thread, two ends of the coils are joined, and I think its bettter if those two points go to ground rather than to hot, given that it makes no difference to the tone.
|
|
|
Post by dannyhill on Jun 11, 2013 5:04:08 GMT -5
Thanks for that titbit John, I'll keep it in mind and apply it where I can.
Danny
|
|
|
Post by dannyhill on Jun 20, 2013 13:37:32 GMT -5
BTW John,
Is there any difference in signal or noise if both pickups are reversed? These being tele pickups and shield wires have been separated from their grounds. Cheers,
Daniel
|
|
|
Post by JohnH on Jun 20, 2013 15:17:55 GMT -5
BTW John, Is there any difference in signal or noise if both pickups are reversed? These being tele pickups and shield wires have been separated from their grounds. Cheers, Daniel I would say not, and some of my diagrams do something like that when it suits the switching.
|
|
|
Post by dannyhill on Jun 29, 2013 15:56:06 GMT -5
Hi John,
I reversed the pickup wiring and swapped the output for input and vice-versa to get the caps on the hotside of the pups only I now get popping in and out of one position from either side plus to another from one side only, i.e going from 3 to 4 and 5 to 4, and 3 to 2. Originally the neck ground was tied to ground and the bridge ground was on a common pole. Now the neck hot is tied to the output and the bridge hot to a common pole. Seems the pups are now hanging more from hot? Time for a diagram UPDATE: I neglected to mention that the switch, that might have seen better days is ok volume wise in 5, 4, 3 but is low in volume when in 2 and 1 is fine, or fine in 2 if I pull to one side but then low in 1. Cheers,
Daniel
|
|