JohnH

Easy! - you can wire it exactly the same way as the on-on-on, such as in this SD diagram: http://www.seymourduncan.com/website/suppo...-sers_para.html Using an on-off-on instead will make this diagram do series-off-parallel. cheers John

Theres one thing you could do to get higher output, which is to do a mod which gives you options for putting the pickups in series instead of parallel - ie they are connected end to end. This results in their signals adding up, instead of averaging. There are lots of modifications along these lines on websites, such as guitarnuts.com. I have a design where theres a toggle for each of three pups to turn it on or off, and another for overall series/parallel - ill post it if interested. JohnH

Pete, I havnt followed the sustainier thread - I figure I should start at page 1 when I do that, but thats a long read! This single pickup, with the reversed phase. I cant see that there is a ground loop problem there. You did say however that it is connected with a single core plus shield. In that case, you might expect less noise when the shield is grounded than when the shield is hot and the core is grounded. Is that too simple? John

I agree with the Doc there. Sometimes, when working out a complex switching arrangement, it is easier to disconnect a coil at one end rather than both ends, to make the switching more practical. That is generally enough to take it out as far as its contribution to the tone goes. But if one end is still connected, I always make sure it is grounded, rather than hanging off the hot connection, or halfway along a chain of coils in series. That way any noise it picks up as an antennae is taken away to ground.

I know what it is Pete! Its a Northern Hemisphere effect, caused by residual radiation created when the US governement tinkered with alien spacecraft at Area 51. In Australia, we are protected from it by extra solar UV rays which reach us through the hole in the ozone layer. Im happier now John

A ground loop, in a guitar, I understand to mean any place where a grounded point has more than one route to get to the ground connection (the jack, in the case of a guitar). The idea is, that this creates a low resistance loop around the grounded connections in which noise signals can be induced of significant magnitude to be affecting the signal. 'Star grounding' is one to make sure this doesnt happen, since it ensures that only one route is available from each point to ground. Thats the theory, But... I can not figure out how these effects become significant enough to be a problem in a guitar (although they are a problem in assemblies of audio equipment where several may be plugged into the mains). Also I cannot create a guitar ground loop to test it, and have tried with large loops of wire! I have a thread on 'Guitarnuts 2' on this, and am still looking for a definative answer: http://guitarnuts2.proboards45.com/index.c...16477808&page=1 Anyone here able to help?

Its hard to be sure, but i think the diagram does not seem to relate to the intended sounds. Im assuming that the bridge pup is on the right? the poles of the switches are the unnumbered ones? they connect to the 1, 2, 3, 4, 5 connections per the switch positions described in your post? If so, I get, after a couple of goes (and also a couple of beers!) 5 Neck Hb 4 Neck single coil 3 Bridge Hb 2 Bridge single coil and Neck single coil 1 Bridge Hb I could be the pups are swapped on my list, or the 1 to 5 numbers are the other way round, however, I cant see how both pups are connected in the middle position, only the one on the right seems to be so. good luck John

You should check this chap out: http://www.guitaristjeffmiller.com/mods.htm Hes done this, and I dont know how he got the electronics, but the results are v cool. You can download his playing of them as well John

I sometimes play the guitar through the line input on the computer sound card, which is also a Soundblaster live. You have to fiddle with the computer sound settings to make sure the lin-in volume is enabled. I do this via an old tape deck as a preamp, but Id think there would be enough signal available to direct inject. Once the sound is in the computer you would be able to do any amount of cool 21st century stuff. You would need to be cautious not to overload your sound system however. A bass or guitar signal can have some large transients and Ive heard of people who blow their hi-fi sytems with them. Real guitar/bass amps are designed to be as tough as a brick in this respect. The point is that recorded music is carefully balanced for level, while what you strum with your fingers is not. So just start at low volume and be a bit careful.

No problem Lovekraft. Here is the best scan I can get of a '71 Recording schematic: http://people.smartchat.net.au/~l_jhewitt/...lprecording.gif It has a switch for high/low impedance. Apparently the 'Signature' model from that time also had low impedance pups, with a separate output jack for high impedance and you could use both at once. regards John

I have the '71 LP Recording diagram in a book - could scan and post it if its like that. It would be a bit clearer than the diagram above.

It depends on which 'signature' it is. Heres the link to the Giobson page with them: http://www.gibson.com/relations/schematics/ you can have Jimmy page, Joe Perry etc. I checked out the Jimmy Page one for a project. Get the pdf files, I found the gif one was too coarse to show all the wires John H

Lovekraft - thats a neat little board, good to know about. I agree that such a mod wouldn't be too hard, although more work than you'd normally put into a little practice amp. But for a few bucks, it could be a good learning experience and with an inexpensive amp, theres not much to lose. Also, being solid state, it should be fairly robust. I also have one of these amps to practice with, and the OD switch is fiddly, so i have also wondered about this. First step is (throw away the waranty..then) open her up and try to figure out how the switch works, how many poles it has etc

I dont have a Tele to check this out properly, but Im looking at a picture of a Tele bridge in a book. Any metal to metal contact will connect string to bridge, and it looks like the string has to press on the side of the bridge plate to change its angle as it emerges from the body. Its under tension so unless there is something non-conductive in the way, it would have to connect, as you suggest.

Yes, that is the effect i was trying to test. Many circuits for coil cutting a humbucker do so by a bypass switch across one coil, which would create this condition, if it was significant. I could not hear any difference in practice though, so I now believe that bypass switches are OK

Lovecraft - my initial expectation matched yours, that the induction effect would not be significant. I have read of it more than once elsewhere however from opinions of guitarists who are also electrical engineers. I like to understand these things to be confident that the circuits that i design are optimised. So I have now done a test, not alas with a spectrum analyser, just with careful listening through headphones. The design of my guitar is such that I can get access to the wiring through a separate cover plare, without removing the pickups etc. It also has quite a range of settings such that with a jumper lead, I could test this, with two settings as follows: A - neck pickup, coil 1 connected between ground and output, all other coils disconnected B - as A, but with neck coil 2 short circuited to itself, (coil 2 was not conneceted to the output) My results were....no audible difference at all!, so 'myth busted' as far as Im concerned, and in accordance with with your post above. I think thats interesting. regards John

Lovekraft - Let me explain further what I on about! (appologies if Im not clear enough). A bypassed coil, although it can't directly send an electrical signal to the output, has currents running just within the coil itself, since the connection from one end of it to the other creates a circuit and generates electricity, drawing energy from the string. Its a similar effect to spinning the spindle of an electric motor, which is harder to do if you short it out because of these induced currents drawing energy. In the bypassed pickup coil, these currents cause changes in the magnetic field which may reach the other, active, coil, affecting the sound. This affect does not happen in a fully disconnected coil, because there is no circuit for the induced currents. I have not got to the bottom of whether this effect is significant, hence my interest in tracking it down, because it may affect the way we choose to design switching circuits. Moreau - with one humbucker and one switch, your options would depend on the switch. It wouldn't be hard to get in-phase series, in-phase parallel and one single coil, I think those are the best three. If you use a 3 pole 4 way switch (could be rotary or lever), the next Id choose would be series out of phase for its super thin sound for strumming. John

Darren - thats good advice. Ive also found it useful to solder up a new switch combination and test it for sounds, before doing the serious work of drilling new holes etc. Its easy to unsolder things, and its saved my poor guitar from several permanent disfigurements! I think everone needs to make their own mind up about number of sounds v switch complexity, and I take your point about having too many. Wouldn't want to suffer brain fade and hit the wrong switches just before the key solo of my next stadium gig....(fades into daydream....) Concerning differences in single coil sounds, my point about using a high fret is to get the neck pup in exactly the centre of the moving string, and pluck the string there, so each coil gets the same input from the string. There is another reason why single coils cut from humbuckers may sound different: if one is formed by bypassing the non-active coil while the other has the non-active coil disconnected. In theory, a bypassed coil, with its ends shorted together, can generate currents in itself that cause a magnetic interfereance with the first coil, and maybe damping.

Good luck! Everything that I have found out about guitar wiring is on a new web site that I have nearly finished. take a look: http://au.geocities.com/guitarcircuits/ The circuit I described above with 4 pots is at the end of the page for two twin-coil pickup combinations Id be very interested in any comments from anyone. regards John

Thanks ..Thats interesting!...any theories on why that happens? Do you still get that if you use a high fret, so the pickup is right in the middle of the vibrating string? Are the poles of the two coils different (eg one adjusted higher than the other)? regards John

Concerning the sounds from a single HB, of the 12 listed above there are 6 different ones, since pairs of combos where both are inverted for phase will sound the same (unless you start combining with another pickup). they are each single coil both coils in series, in or out of phase both coils in parallel, in or out of phase In a bridge position, the two single coils sound similar but a bit different, in the neck position they sound virtually the same Coils out of phase make a funky thin sound, not hum cancelling, rather low volume Parallel in-phase is a bit brighter than series in-phase, and is hum cancelling. I find this the lowest noise setting of all and very useful. To pick say the best 4 out of the six, Id skip one of the single coil sounds and the parallel out-of-phase. I have a switch arrangement for this here: http://people.smartchat.net.au/~l_jhewitt/...uits/1H4way.gif There is another technique also, which is to put a capacitor across one of the coils in a series connected humbucker. Ive not tried this, but it is intended to give a coil cut sound for the high harmonics, keeping the humbucker noise cancelling and deeper tones. Must try it some time! If however, you are building up to a circuit with 2 HBs, then the other single coil can be useful (reverse phased), to get a hum cancelling out of phase sound between pickups. Theres heaps of posibilities and good/bad sounds! I think that getting hum cancelling and phasing correct is the key to complex guitar circuits, trying to weed out the duff noisey combos and concentrate on the good sounds. (my current switching on my 2Hb guitar has 30 sounds). Let me know if youd like more stuff that i have on phasing and humbucker switching.

Thanks crafty - Hey Tonemonkey, have you picked a scheme yet?, if not, heres a little further research, based on using 4 push-pull pots if that sthe way youd like it: The Jimmy Page wiring is on the Gibson site, but dont look at the gif file, use the pdf (the gif file does not resolve all the lines in the drawing, confused me for a while): http://www.gibson.com/relations/schematics.../pagewiring.pdf Deaf Eddie has a couple of variations on the JP wiring, here: http://www.deaf-eddie.net/pushpull/jp_setup.html I quite like his version for the ES333, which gives you a hum-cancelling parallel wired option on the bridge pup, as well as phase inversion, single coils and both pups in series. Another option would be as follows, using four DPDT switches, which could be on the push-pull pots. SW1 - coil cut on both pups SW2 - converts bridge pup from series to parallel - humcancelling SW3 - overall phase change of the bridge pup (also selects the other bridge coil if SW1 is on) SW4 - puts the coils of the neck pup out-of phase with each other (funky thin strumming sound, an aquired taste, but I like it alot) That last one is not hum cancelling, but if you mix it with a single coil on the other pup, it is hum-cancelling (ive got tis on mine), and you get a nice bright single coil type sound with no hum. If the above is of interest to anyone, I will post a diagram. John

Crafty Im glad we're all cool, but I do have a question about interference between the separate pots for each pickup! I dont have such a guitar to test it on, so you may be able to explain whether it is an issue or not: If you take as an example, the following basic LP wiring, straight off the Gibson site: http://www.gibson.com/relations/schematics...ms/lespaul2.gif I can see that if you select one or other pickups, the individual controls will work fine. But if you select both with the centre position of the pickup switch, it looks to me that: with both on full volume, adjusting one tone pot will equally affect both pickups if you turn one volume pot all the way down, you'll lose volume on the other pickup too maybe this is not a problem in practice? cheers John

Have tried LP's, unfortunately not owned one. Great guitars, no-question. Just putting a personal view: Ive never found the simple passive tone controls on guitars very useful and would rather use switching to change tones.

A further thought. If it were mine, I think I would not want the separate tone and volumes, because they can interfere with each other when combined, and I think these things are better done on the amp (just my opinion of course) I have a 2 x h guitar, with 30 sounds and some unusal wiring that you may be interested in. It is a Shergold Masquerader, slighty modified by me. Heres my page on it, with the circuit. It could work for you if you didnt want the independent pots, but Id increase the value of the pots which are very low at 100k. Check out also, the link to the web site on this make, which has lots of awesome ways to wire 2 humbuckers. http://people.smartchat.net.au/~l_jhewitt/...d/Shergold.html