circuit check

[simes]

I wonder if one of our more knowledgeable members would mind checking this circuit for me. I have no electrical knowledge, and particularly I don't understand tone controls, despite having read up on them.

www.combat-tkd.com/circuit2.pdf

This is for a Strat with 3 GFS Lil Killers, common tone control for neck and middle pickups, separate tone for bridge pickup, and master volume. I intend to hardwire the middle pickup in local parallel, and run the bridge and neck pickups through a 4PDT miniswitch for local series/parallel.

Thanks,

Simes

[sumgai]

simes,

The reason it doesn't make sense to you is that there's a gross error right in the middle of the page!

Essentially, no matter what pickup(s) is/are selected, both tone controls will be in the circuit at all times. Let me repeat that - both tone controls will be effective for each of the 5 switch positions, period.

Another error, not so glaring, but one that many beginners make, is forgetting that when you involve a pickup in a series connection, and you want it to have a tone control, you must connect said control directly across said pickup - you can't wire it with one side to ground, as you would for a pickup in a parallel connection. Now that that's been pointed out, it should be obvious as to why, but if what I just said doesn't make sense to you, just ask, and we'll explain it in more detail.

Beyond that, what you linked to, and what you said you wanted in your last sentence doesn't seem to mesh very well. Perhaps if you were to write down a "table" of what pickups you want selected for each switch position, and whether in series or parallel where appropriate, we could help you get to your goal.

BTW, that website has another circuit (neither of them linked from anywhere else on the site!!) that looks suspiciously like a Mike Richardson mod........

HTH



sumgai

[simes]

Hi sumgai.

OK, that website I linked to is my own non-guitar-related website, and was the only way I could figure out how to link to the image! The other circuit is one I came up with based on existing mods here, and linked to the post "3 pickups 8 options" (or something like that) in the schematics section, before realising that I should have put it in this section first. By then it was too late for me to modify.

Regarding this circuit, what I want is the following:

1. neck
2. neck in series with bridge out of phase
3. neck in parallel with bridge
4. middle in parallel with bridge
5. bridge

I think that the superswitch should give these combinations. My problem is the tone and volume controls, as I really don't understand them, and what you said in your posts means very little to me! I'm mainly concerned with having a tone control for the bridge pickup, as I like my neck and middle pickups trebly and set the amp thus, rolling back the treble on the bridge pickup with a dedicated tone control. If I can have the other tone pot controlling the neck and middle pickups, or just the neck, then great.

In my last paragraph, I mention series/parallel switching, but this is not shown in the image, because I know how to do that (Ha! See? I do know how to do a few things ;D - actually, I did it successfully on another axe). The thing is to use half a 4PDT switch to switch between internal series and parallel wiring of the coils of the neck HB (what I referred to as local s/p) and the other half to do the same for the bridge pickup.

So basically I need someone to (a) confirm/correct the wiring of the superswitch as per the options mentioned, and (b) tell me how the hell to wire in those pots .

Cheers,

Simes

[simes]

Anyone? You wouldn't want to be responsible for me receiving the PU's and just wiring them straight to the output jack, now would you ... ?

By the way, my ears are still ringing from seeing Johnny Winter live last night in Pontevedra (Spain). He's still got it ...

[sumgai]

simes,

I'm away from my main machine at the moment, it'll be awhile before I can get back on it, and fire up my CAD program for some drawing activity. Sorry to make you wait a bit longer, but hang in there..........



sumgai

[simes]

No problem! I won't have the PU's for another week anyway.

If the series position 2 creates a problem with the tone pots, I can do without a tone control for that position. The only indispensable tone capability is for the bridge PU in positions 3, 4 and 5.

Thanks,

simes

[simes]

Got my Lil Killers! A week for shipping to Spain by normal parcel post. Not bad!

[simes]

How about this, then?

www.combat-tkd.com/circuit3.pdf

Here I've changed it so that one tone pot affects the neck PU and the other affects the bridge PU. I think. Would this work? Could I do away with the neck tone pot altogether and just have one tone pot for the bridge (use the hole in the scratchplate for something else)?

Note that the blue line between the tone pots isn't connected to the black line that goes between the superswitch and the volume pot.

Any help would be really appreciated, as I have my new PU's and just can't wait to try them.

Cheers,

Simes

[ashcatlt]

above here, sumgai said

Jul 23, 2008 11:55:24 GMT -5 sumgai said:

...
Another error, not so glaring, but one that many beginners make, is forgetting that when you involve a pickup in a series connection, and you want it to have a tone control, you must connect said control directly across said pickup - you can't wire it with one side to ground, as you would for a pickup in a parallel connection. Now that that's been pointed out, it should be obvious as to why, but if what I just said doesn't make sense to you, just ask, and we'll explain it in more detail.

Seems like he's been more intermittent than usual lately, so I'll save him some typing, by linking and quoting this thread where he actually did provide detail.

Dec 21, 2007 2:50:54 GMT -5 sumgai said:

In order to affect the tone of a pickup, one usually wires a cap, through a pot, between the hot lead and ground. But in a serial connection, we can't do that - taking the middle or upper-most pup in a serial chain, and sending the signal to ground via the cap, we've just bypassed the lower pup(s), for at least some of the frequency spectrum. The results, as you've noted, are less than optimum.

If you must have a tone pot somewhere within the chain, here's what you need to do: For controlling only one pickup, connect one side of the pot to the pup's hot lead, the other side (of the pot) to the cap, and the remaining cap lead goes to the pup's negative lead (don't wanna call it ground here, that'd be misleading!) For controlling two pickups with one pot, you simply skip the intervening negative lead-to-hot lead connection, and wire it just noted.

FWIW, I am not in favor of such a scheme, due to the loading effects upon the several pickups. Instead, I'd recommend that the optimum course of action would be to institute a Master Tone control.
...
HTH


sumgai

[simes]

Thanks ashcatlt.

From this I gather that the new configuration I posted would have one pot affecting positions 1 and 3, and the other affecting positions 3, 4 and 5, while position 2 (series) would not be affected by either pot. And if I did away with the neck tone pot (which I am tempted to do, as I never use it), I would just have a pot for the bridge PU in positions 3, 4 and 5.

Presumably it’s not possible to have the bridge tone pot affecting both the position 2 series combination and the parallel/single combinations of positions 3, 4 and 5. I suppose I could use the erstwhile “neck” tone pot to control the bridge part of position 2 by connecting one side to B+, the middle one to B- and the other side to ground via a cap.

Another doubt that I have is regarding which terminals on the pot are used for tone controls. On most diagrams I’ve seen, one pot uses the “left” terminal for hot and the middle one for ground, while the other one uses the middle on for hot and the “left” one for ground. Or something like that. Or doesn’t it matter?

So, would this work as it stands?

[ashcatlt]

In the case of a tone pot, it doesn't matter which lug connects to what, the effect will be the same.

---Edit---maybe that was too vague, add to the above statement: as long as one of them is the wiper. The choice of the other lug depends on which way you want to turn the pot.---Edit----

I thought the above quote was fairly clear, but then I already know what he's talking about. If you want both tones, you're not going to be able to share the capacitor. Get another one, they're cheap. The fun part is you now get to experiment with values to find the perfect cap for each of the pickups, if you want.

Do this for each of the pots:

1) connect the wiper to one of the leads from its respective pickup before the switch. Doesn't really matter which, but for convention sake why not use the +?

2) connect one end of the capacitor to the other lug (I'm not sure if it should be the CW or CCW, whichever one you've got it on now...)

3) connect the other end of the capacitor to the other lead from the same pickup.

Done.

This will have them each affecting their respective pickups in all parallel positions. In the series position, the tone pots will roll off the treble from their respective pickups, but will also allow the treble from the other pickup to bypass the one whose tone is turned down, creating a sort of half-parallel thing.

[simes]

Like this?

www.combat-tkd.com/circuit4.pdf

When you say "a sort of half-parallel thing", are you referring to the tone pots, or will this in some way affect the series nature of the bridge/neck combination in position 2?

[ashcatlt]

That's very close! As you've got it drawn now, though, you'll be turning the knobs in opposite directions.

When I say half-parallel I mean kind of like what people around here sometimes call broadbucker.

When you turn down the bridge tone (for example), you'll roll off some of the treble from the bridge pickup. Some of the treble from the neck pickup will take the path through the bridge tone cap, around the bridge pickup (rather than through) and will be in parallel with what remains of the bridge signal.

[simes]

OK, I started wiring up the pickups and switch. Due to the size of the superswitch and the 4PDT switch I’m using for local series/parallel on two of the PU’s, I’m going to have to settle for just one tone pot. This means either a master tone or just a bridge tone.

If I decide on a master tone, am I right in thinking that I should have the signal coming out of the superswitch and going (a) to the volume pot and (b) to the middle lug of a tone pot and thereafter out of one of the side lugs of the tone pot and to ground via the cap?

If I decide on the bridge tone pot, I think I understand what you’re saying. Do you mean that position 2 with the tone pot rolled back would be something like [neck > bridge (OoP)] + [treble from neck PU]? I don’t know whether this would much influence the “series sound” of this position. If the effect on the sound is minimal (considering that the whole point of this position is to get a strong OoP sound thanks to the series wiring, rather than the weak parallel OoP), then I would go with the pot wired across the PU as suggested. If it would make for a big drop in sound, then I’d just wire the pot to ground like a normal tone control, and just have it affecting the bridge PU in positions 3, 4 and 5. What do you think?

If I want to turn the knobs CW for “maximum”, I’m assuming that the volume pot is OK as shown, but which side of the tone pot should be connected to the cap?

Sorry to ask so many questions. I’m a bit loathe to try stuff out with a view to changing various configurations until I get the one I like, because my soldering technique is not good and will no doubt end up damaging stuff.

Cheers,

Simes

[ashcatlt]

Aug 6, 2008 1:57:46 GMT -5 simes said:

If I decide on a master tone, am I right in thinking that I should have the signal coming out of the superswitch and going (a) to the volume pot and (b) to the middle lug of a tone pot and thereafter out of one of the side lugs of the tone pot and to ground via the cap?

That'll work fine

If I decide on the bridge tone pot, I think I understand what you’re saying. Do you mean that position 2 with the tone pot rolled back would be something like [neck > bridge (OoP)] + [treble from neck PU]?

Yep.

I don’t know whether this would much influence the “series sound” of this position. If the effect on the sound is minimal (considering that the whole point of this position is to get a strong OoP sound thanks to the series wiring, rather than the weak parallel OoP), then I would go with the pot wired across the PU as suggested.

I've never actually gotten around to trying this, so I've got no practical knowledge of what it will sound like. Hoping one of the guys who have might chime in on that part.

If it would make for a big drop in sound, then I’d just wire the pot to ground like a normal tone control, and just have it affecting the bridge PU in positions 3, 4 and 5. What do you think?

I'm thinking you're "bridge tone" would act (at best) as a master tone in any position where the bridge was included.

If I want to turn the knobs CW for “maximum”, I’m assuming that the volume pot is OK as shown, but which side of the tone pot should be connected to the cap?

In the case of the tone pot you'd like all the resistance of the pot between the pickup and the cap>ground when turned up to max (no treble cut). That is, you want to turn the wiper toward the lug with the cap to turn the tone down. Does that help? I never use the things and have trouble remember which way is supposed to be up...

Sorry to ask so many questions. I’m a bit loathe to try stuff out with a view to changing various configurations until I get the one I like, because my soldering technique is not good and will no doubt end up damaging stuff.

Cheers,

Simes

Don't be sorry, this is how we learn. Besides, this is about the sum total of my social life.

[simes]

OK, that's great. I think that is everything cleared up. Thank you very much!

I'll see if I can finish the wiring this afternoon, which means you can probably expect me back tomorrow, burnt and besoldered, asking in bewildered tones why my axe only makes noises in two of the positions ...

[simes]

Buzzing, blank spots, strange noises ... I'll be taking it in to the guitar shop tomorrow so someone who knows which end of a soldering iron to blow down can take a look at it.

[simes]

PU's wired in and working. Thanks guys. See review in the PU's section.

By the way, the following ...

Aug 8, 2008 16:12:01 GMT -5 simes said:

... so someone who knows which end of a soldering iron to blow down can take a look at it.

... was a reference to my own ineptitude, and I'd hate for anyone to think I was being disparaging about the help I received from our esteemed colleagues .

[ChrisK]

so someone who knows which end of a soldering iron to blow down

For Everyone's Information (and no one in particular), a general rant on soldering.

rant

The application of forced cooling air-streams to non-solidified solder joints is one of the primary causes of "cold" (as in not properly cooled and set) solder joints. I know it's hot, but hey, that's why we invented needle nose pliers.

"Cold" solder joints will often work OK....for a while. The lack of proper forming leads to internal corrosion.

The other leading cause is non-clean (oxidized, inappropriate materials, dirt,...) stuff.

ALWAYS use electronic rosin core solder.

NEVER use plumbing solder or flux.

ALWAYS use excellent ventilation in the work space.

Clean the completed joint with alcohol (and a Q-Tip) if possible. Don't get any alcohol inside any pots or switches.



And ALWAYS, if you're using lead-based solder (if you can still find it) WASH YOUR HANDS BEFORE TOUCHING ANYTHING (such as food, your face or mouth, cigarettes, alcohol in other forms....).



From Wikipedia
en.wikipedia.org/wiki/Soldering

Soldering defects
Various problems may arise in the soldering process which lead to joints which are non functional either immediately or after a period of use. The most common defect when hand-soldering results from the parts being joined not exceeding the solder's liquidus temperature, resulting in a "cold solder" joint. This is usually the result of the soldering iron being used to heat the solder directly, rather than the parts themselves. Properly done, the parts to be connected are heated by the iron, which in turn melts the solder, guaranteeing adequate heat in the joined parts for thorough wetting.

An improperly selected or applied flux can cause joint failure, or if not properly cleaned off the joint, may corrode the metals in the joint over time and cause eventual joint failure. Without flux the joint may not be clean, or may be oxidized, resulting in an unsound joint.

Movement of metals being soldered before the solder has cooled will cause a highly unreliable cracked joint.

/rant


(If you've been soldering in a bar or pub, and they've been putting up with you thru this, you may have to pay for the alcohol to help clean (out) the joint. )

[simes]

Ah, wise words indeed.

Now, how about a cure for shaky hands?