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single coil pick up problems.

I fitted a single coil pick up to my gone fishing cbg with a volume control but alas nothing would work!

I wired every thing up as per instructions.

mmm me thought I'll try the peizo wired that to the volume but no worky?

so I wired the peizo directly to the jack its working! so I re soldered the single pick up no worky again

swapping wires around made no difference.so out came the single pick up .

I then put the earth wire to the amp jack plug ..tip.. and the red wire to the lower pin it worked.

I tap the pick up and it made a tapping noise through the amp .so that proved that the pick up is working ok ,but why it wouldn't it work wired directly to the jack ,the peizo did so the jack is wired ok.

here's some pictures..

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Permalink Reply by John Sawyer on July 13, 2014 at 7:18am

Darn, just glued the box closed. Guess I'll have to build another!

Serial? Really? I thought that in Parallel they'd get more kick...

Shows you what I know! :-)

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Permalink Reply by The Phrygian Kid on July 13, 2014 at 9:35am

i'd strongly advise members against wiring piezos in series, this is not wise, and more 'power' will not necessarily make you any happier.

combining them in parallel will Improve things however, up to a certain point; it will reduce (halve) the impedance mismatch between the amp and the pickup where combining them in series will increase (double ) it...

of course there are those who consider howling feedback art, each to their own :)

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Permalink Reply by The Phrygian Kid on July 14, 2014 at 2:29am

Ah well I'm sure you have your reasons for thinking it great...
I've built a lot more than three guitars and have my own reasons for cautioning the reader.

I can't be bothered with any lengthy debate, but I'll suggest this: IF 'power' is an issue and IF there are zero feedback issues (all pickups, especially piezos can feedback, or they are just not producing a hot enough signal) then perhaps you are overdoing this 'protection from external noise' business.. You can bury em in eight inches of cold steel for example, I'm sure there will be very little handling noise and some output issues..
Just a thought, if it's working for you then great, peace :) I'm just tempering your advice with a contrary opinion.

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Permalink Reply by JL on July 15, 2014 at 7:16am

John, I didn't see in here if you changed the volume POT wiring.

The pickup wires go to the left and right lugs of the volume POT.

The TIP connector on the jack goes to the center lug and the SLEEVE connector on the jack goes to either the left or right lug. It doesn't really matter which, one will give you a clockwise volume knob and the other will give you a counterclockwise volume knob.

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It is common (but not essential) to 'ground' the metal case of the POT to the SLEEVE connector of the jack so you don't get humm every time you touch the volume knob. That's why the drawn picture shows the volume POT's right lug bent backwards to touch the POT's case and the solder connecting one pick up lead, the bent lug, and the SLEEVE connector from the jack.

With coil pickups it is also common to 'ground' the strings to that same SLEEVE ground point to reduce humm. A metal string moving in the magnetic field of the coil pickup generates its own AC charge and long metal strings can act as antenna for things like fluorescent lights.

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(And now my apologies for the electronics 101 that follows to any of y'all that already know this)

The outside lugs of a POT are the opposite ends of a huge resistor, 250,000 or 500,000 ohms is common. The pickup generates 0.05 to 0.20 Volts. With the pickup connected to the opposite ends of the resister, the POT acts as a uniform voltage divider. The knob moves a sweep connector along the resister and the center lug is your connection to that sweep. With the knob turned 80% of the way, the center lug picks up 80% of the 0.05 to 0.20 Volts. With it turned 30% of the way the center lug picks up 30% of the 0.05 to 0.20 volts.

If the pickup is not connected to both ends of the POT's resister, then it acts as a variable load, and it is trying to push that little 0.05 to 0.20 volts of power through 50,000 to to 220,000 ohms of resistance, and you will only get 0.00001% of the 0.05 to 0.20 volts coming out of the center lug.

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Permalink Reply by The Phrygian Kid on July 15, 2014 at 8:55pm

Um... If you only connect to one end of a pot it will be a variable resistor...
Ie the resistance will vary...
This is how multiple volume controls eg Gibsons etc are usually done, and a lot more than .0001% or whatever gets thru...
I do 'blend' controls like this all the time..

Way finder to your other, have you heard of the impedance mismatch between piezos and regular guitar amps? This is what causes the 'quack', almost a square wave... Well adding another piezo in series will DOUBLE this discrepancy....

Look pickups.. It's a very subjective thing.. Guys string up their first few cigar box guitars... And it sounds GREAT,. To them. Dude I remember the rush myself. It doesn't mean it is great. (Nor necessarily that it is not)...
We talk about piezos and one guy hates em.. Another says hey I've used em dozens of times and they work GREAT! Hmm what does that even mean? Does this guy have a 100w Marshall or an iRig ???

Now the truth is no one uses disc piezos in a production instrument. Not even in the $75 first act jobs at K Mart. Use em if you must but that's the truth of it. So putting two of em in series?? Well take everything I hate about em... And double it lol. :)

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Permalink Reply by BUGGY (C) on July 15, 2014 at 11:25pm

If you put 2 directly under the bridge it works like a rod piezo
Make sure there is some pressure on them

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Permalink Reply by The Phrygian Kid on July 16, 2014 at 9:48am

You can put it down to taste mate sure..

Especially as you have indicated that you, having at some point in your life drained an entire can of fosters larger, HAVE NONE :p

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Permalink Reply by BUGGY (C) on July 15, 2014 at 7:43pm

Whats the pot value if its too high it may be a problem?

Grounds is normally to the outside of the jack socket and would be one issue..

You can also get phase cancelling with 2 pickups but this is mainly the fun of using 2 wound pickups, hence why a strat middle pickup is different and wired differently.. and why a humbucker has north and south poles.