Kingcaster uke build : part 10 – How to wire it up (properly)

Earlier this week I heeded Daniel Hulbert’s sage advice and decided to test out the wiring on my electric ukulele build. You will remember that I was being a right smart-arse refusing to test until I’d painted the body. Perhaps it was the paint fumes talking? What would you say if I was to tell you that having tested the bloody thing, that it wasn’t working? Yeah, I know… what are the odds of that!

Actually, although hugely disappointed, I wasn’t actually that surprised. Things were going too well! I quickly fell into a dark depression, barely able to eat, only able to communicate via grunts. You already know how limited my electrical knowledge is. There was absolutely no chance in hell that I was going to dig myself out of this hole… or so I thought.

Daniel took me aside, slapped my face a couple of times and made me see sense. His exact words were: We’ll sort it out. What a guy! It was exactly what I needed. What followed was some long-distance advice and support that (fingers crossed) has only gone and fixed it! WAHAY! I can’t overstate how appreciative I am for your help Daniel. You are a brilliant, clever man! Thank you!I promised at the very start of this project that I would share the good and the bad with you. Let’s see if I can put this into words…

Let me remind you of where I had got up to…
Here is a picture of the wiring as I left it in a recent post. I’d followed the
Seymour Duncan diagram and soldered everything up. I had a few doubts
over some of the wires
, but I was hopeful that it would all come good.
I bought some crocodile clip wires, hooked it all up and plugged it into
an amp. Then holding the pickup close to the strings of an electric guitar
I strummed. Even before I’d plucked a string, I knew that I had problems;
The thing buzzed like an angry bee. Everything I touched clicked
and buzzed. I could only get a clean sound out of it in certain
settings – everything else was a mess! I cried like a baby!
Something pretty fundamental was wrong and I didn’t know where
to start diagnosing.

 

Daniel Hulbert (no doubt aided by my picture of my soldering) was
suspicious of my connections. I didn’t know how to prove they were good,
but Daniel did! I bought the multimeter pictured which has a continuity
buzzer. You switch the multimeter to this setting and then touch the
two probes to either end of the part of the circuit that you want to test. If
they are connected then the machine will buzz. If not, if won’t. Pretty easy!
I tested every single wire and sure enough it looked like one wasn’t right.
With a new found sense of optimism I then began to wonder if actually
there was a way of testing the components to see if they were working
as they should. I googled and found some information on how to test
the pots.

 

Guitar pots come in a number of flavours, but the two most common ones
are A and B. What I discovered today was that depending upon where
abouts you are in the world, A and B might mean completely the opposite
things. Forgetting the naming for the moment… Volume pots are typically
“linear” – i.e. turning it 50% affects the volume by 50%. Tone pots are
typically “logarithmic”. i.e. non-linear. “A” and “B” tell you which type
of pot you have. I had followed the instructions from the seller of my
pots, but I figured I’d test them anyway. The first test I did was to
measure the total resistance of each of the pots. They’re meant to be
250K. Actually, one is 201K and the other is 265K. Next I thought
I’d test which was linear and which was logarithmic. Would you
believe it if I told you that mine were the wrong way around?
Yeah, I know! I’d been given some bad instructions from the seller!
As far as I can tell this wouldn’t have caused the problems I was
having, but I wanted to fix it nonetheless. The good news is that
I was able to confirm that both pots were working. I then wondered if
I would be able to test the capacitor. I couldn’t figure out a way
of doing it with a multimeter, so I took a leap of faith and moved on.
One thing that Daniel had warned me of was the fact that some
capacitors need to be wired the right way round. Apparently
they’re marked if this is the case. Mine didn’t look like one of these.

 

I removed all wires and started again. Last time I used some old wires I’d
salvaged from a wreck of a guitar. This time I bought new. Last time I was
a bit fast and loose with the solder. This time I paid more attention. I
tried to use as little solder as possible and to keep it neat. I also tried to get
all of the metal touching so that the solder really was simply holding it
together rather than conducting. It’s not beautiful by any means, but
you can see above the Mark II version of my wiring. You can’t really
tell from the picture, but the pots are the other way round.

 

Next I connected it all up again and tested. At first I figured that I’d
made it worse because there was no sound at all! Actually, what I
was hearing was no buzzing! When I put it up against the strings and
strummed I heard a clean beautiful strum through the amp. This time
the volume did what it was supposed to do and the tone control
was noticeably affecting the tone of the sound! WOW! Is it a fluke?
We shall just have to wait and see. Until then, I’m just going to
keep on smiling!

So there you have it. I’ve learnt a hell of a lot over the past couple of days. I’m feeling pretty proud of myself!

But hold on a second…

Unfortunately there’s been a bit of hiccup on the painting side. I’ll tell you more about this later…

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