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Post by 4real on Jun 1, 2007 17:35:31 GMT -5
So...I am going through my boxes of electronics and sustainer experiments and found this very cheap pickup coil...
Has anyone explored the idea of using such a coil as a dummy noise cancelling noise to be switched in when splitting a Humbucker?
This coil, or one I could make, is preety thin and could possibly fit under the HB as a third coil...any thoughts?
pete
ps...didn't find much with a search, but I'm sure there has been talk about dummy coils...
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Post by dd842 on Jun 1, 2007 18:01:02 GMT -5
So...I am going through my boxes of electronics and sustainer experiments and found this very cheap pickup coil... Has anyone explored the idea of using such a coil as a dummy noise cancelling noise to be switched in when splitting a Humbucker?This coil, or one I could make, is preety thin and could possibly fit under the HB as a third coil...any thoughts? peteps...didn't find much with a search, but I'm sure there has been talk about dummy coils... Hi Pete, I believe that you are correct that this has been discussed here, but I'll be darned if I can find it yet ... I thought I would mention it though, in the hopes that some of the regulars who are thinking it sounds familiar may have their collective memories jigged. I am estimating it was six months ago that I read it. But I poke around old stuff too ... so it could have been an older post that i merely "read" six months ago ...  I'll keep looking ... but does that ring ay bells anyone?  Dan |
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Post by JohnH on Jun 1, 2007 18:24:18 GMT -5
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Post by 4real on Jun 1, 2007 18:28:22 GMT -5
So...doing a bit more reseach...over at PG I found this little thread that had this intriging bit... projectguitar.ibforums.com/index.php?showtopic=22637&hl=dummyWhile I have a small coil to experiment with, I could imagine a thin coil (similar to the style developed in the sustainer thread) (perhaps 2-3mm thick around a wide steel core, about the size of the base of an HB that fits in there and could be added to any pickup and switched in to split... I think shur came up with something like this built into a trem plate for strats... The other thing that occurs to me is that small transformer or relay coils could be used for similar effect (if winding is not your thing)...thoughts? What is the effect on tone with the addition of a dummy coil do you think...how complex would the switching be to do this do you think? Could a dual gang pot be used to blend out one coil and blend in the dummy coil as the split increases... pete |
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Post by 4real on Jun 1, 2007 18:52:32 GMT -5
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Post by 4real on Jun 1, 2007 19:19:38 GMT -5
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Post by JohnH on Jun 1, 2007 20:01:51 GMT -5
My guess on tone suck:
Put the dummy in series rather than parallel, then at least it is not grossly shunting down the volume. The basic volume should be about the same as without the dummy. But if the dummy has comparable properties to the main coil, there would be some darkening due to raised impedances. If you feed the signal through a high impedance buffer within the guitar however, then I think there will be no significant loss.
John
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Post by 4real on Jun 1, 2007 23:40:46 GMT -5
Perhaps...
This theory is interesting though....
It implies a much lower impedance coil could be used if it were bigger in size...like the size of the rear trem plate (to go to extremes) and perhaps have less of a tone suck effect...maybe
I read the kinman dummy coil on it's stacked model has thicker, less turns of wire and significantly more steel core compared to the magnetised sensing coil on top...
Anyway...that's the beauty of these things, like the sustainer, experimentation is the key...so instead of chatting so much, I should give it a go and report back...
pete
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Post by UnklMickey on Jun 2, 2007 2:29:48 GMT -5
the absence of an iron core will also lower the inductance.
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Post by 4real on Jun 2, 2007 4:44:18 GMT -5
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Post by 4real on Jun 11, 2007 5:27:52 GMT -5
Ok...so I found a couple of coils, about 5k ohm each with no cores on plastic bobbins less than 5mm deep...was thinking of trying them out on my strat single coils as an experiement. Any opinions on how such an additional noise cancelling coil should be connected (series/parallel) Also, any predictions on the outcome??? pete |
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Post by UnklMickey on Jun 11, 2007 14:24:46 GMT -5
Hi Pete,
I'd say series. The DC resistance of the dummy coil might be similar to the SC you're trying to cancel, but without any cores, the inductance will be very low. If you connected in parallel, I would expect it to load down the active coil, especially at low frequencies.
it must be oriented in the same axis as the active coil, then determine the correct connections to subtract rather than add to the hum... or just flip the coil 180 degrees if that's easier.
prediction: if this coil collects the same amount of hum as the active coil, it will do a decent job of hum-cancelling without too much affect on the tone. -- likelyhood that it collects the same amount of hum, modest. If you are extremely lucky, it will collect more hum than the active coil, and you can partially shunt the coil. This will cause the dummy coil to have even less effect on the tone. If you are less lucky, the dummy won't collect as much hum as the active coil, and you will get partial hum-cancelling.
There is a way to use a dummy coil that will sound almost exactly like a SC without hum. It is more complicated. It's also a million dollar idea, so I won't discuss it in public.
cheers,
Unk
EDIT: I just noticed this is post #2500 for me. probably about the same as the number of pages on your sustainer thread over at PG. I'm not sure if that's reason for me to celebrate or for me to STFU. lol
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Post by JohnH on Jun 11, 2007 14:53:43 GMT -5
I'd also agree with series connection for this coil. I think it will probably have very little effect on the tone. You'll hear whether or not the hum is balanced out.
John
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Post by sumgai on Jun 11, 2007 17:51:44 GMT -5
Pete, I'd also agree with series connection for this coil. I think it will probably have very little effect on the tone. You'll hear whether or not the hum is balanced out.
John In addition to John and unk's assertions, I'd like to add....... Consider the case unk points out where the dummy does not get enough energy to sufficiently cancel the hum. Well, since you've already got power on-board, you might consider adding a bit of amplification to the dummy's signal, via one of John's FET circuits. This will help to isolate some, though probably not all, of the impedance issues, yet should boost the OoP hum to a level that will reduce the final output's objectionable noise down to a tolerable level. There are two ways to look at RFI (radio frequency interference, what we're all up in arms about). But the distinction is not important here, what is important is that most schools of "Buck that Hum" believe that you must have the two coils as close to each other as possible. There are other schools, obviously, who say that it doesn't matter, so long as the dummy coil is aligned in the same plane as the signal coil. Remotely located coils may or may not be equal to the task without help from an amplifier of some sort. I believe that the product you pointed out above (from Suhr, Fralin and others) uses this concept. They may call it "fine tuning", but the underlying concept is easy to understand. After doing a proper QtB job, I've never needed anything else. I've been in some rather nasty environments where other people's instruments simply can't be used without cringing after they stop playing, until they kill the volume entirely. Not mine, I just pluck away, and never touch the control after the last note. I occasionally get a stare of envy.  I can get within 12 to 14" of most any amp before I get noticible hum from the protruding power transformer. I have to wonder, why can't others get similar results from shielding, such that they don't need things like dummy coils? I know I'm not lucky or unique, many other members here have shared similar results, and I'm not the only tech in town doing this mod/upgrade for folks. We wouldn't be doing this continually if it didn't work, and if it didn't get good press ("word of mouth") from satisfied users. Truly, it does give me pause to consider........ HTH sumgai |
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Post by 4real on Jun 12, 2007 3:59:18 GMT -5
Thanks for the replies...it all sounds encouraging. I was surprised to find that this guitar did come with conductive paint in the control cavity and foil backed cover. I have in the past rewired completely in shielded cable and found iot to make a dramatic improvement...the sustainer strat with all those switches is unshielded, but wired in this way and is very quiet dispite it's typical single coils. I intend to do the same with this guitar when I rewire...which is the next stage now my driver is done to replace the mid pickup  Ah...not to worry, the test coils could easily be fitted with different core materials...if desirable...or not! I guess it is an idea that comes up a bit with only marginal experimentation. Part of the appeal to me of course is that I have developed some skills in winding such coils through the sustainer project and would like to capitalise on them a little more. The key difference between the sustainer thread and a lot of other talk fests on such topics is that along with the speculation is a considerable amount of experimentation, trial and especially error. This forum is another practical forum for doers as well as thinkers... The sustainer thread has some 2922 posts as of today...not all mine of course, and a lot of it redundant...a significant amount of typing none the less. It is the substance behind it that should really be noted. Anyway...it is a pleasant form of procrastination if nothing else... cheers... pete |
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Post by sumgai on Jun 15, 2007 12:42:43 GMT -5
pete,
Hey, no swearing! This is a good, clean, wholesome, family friendly Forum! ;D
sumgai
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Post by 4real on Jun 16, 2007 20:28:48 GMT -5
ok...so I am into the wiring, so while I am there I couldn't resist adding this coil to the underside of the pickup....   The whole thing was non-invasive and pretty easy to do. It sits over the pickups screw poles and is no deeper, so you know it will fit back in there...I have simply wired two new leads to it for further experimentation...   how it is used is yet to be seen, but the way it is fitted it will sense some of the signal through the screw poles of the coil being split. It now occurs to me that this additional coil could be used as a kind of coil tap to add or even subtract, from the HB as well as the original intention of noise reduction...still, it's in there now so I have something more to play with...I could even fit another on there...hmmm pete |
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Post by 4real on Jun 17, 2007 4:51:17 GMT -5
Hmmm...well I finished the rewire and did a few experiments with this...nothing conclusive...now I find there is a break in a wire, so who knows...fortunately (or not) I have another coil that I can test without attaching it to anything...
Doing a bit of a search on something else would you beleive I found this...
hmmm...nothing new it would seems....obviously didn't catch on...
pete
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I can get within 12 to 14" of most any amp before I get noticible hum from the protruding power transformer. I have to wonder, why can't others get similar results from shielding, such that they don't need things like dummy coils?