Introduction: DIY Pickup

Picture of DIY Pickup

This is a simple and cheap way to make your own electronic pickup using a relay switch!

The relay switch has a fine wire coil inside which is perfect for a pickup. Combined with a strong magnet it can produce a really good sound.

This pickup only works for one string. However, if you want to use it for multiple strings, you can combine multiple pickups to create one larger unit.

Step 1: Parts

Picture of Parts

What you'll need:

PCB relay switch:  I found the relay I used on an old circuit board. Look around first! You can find them on plenty of circuit boards that are being thrown away.                 

1/4" mono audio jack: You can pick these up pretty cheaply at most electronic stores (Maplin/RadioShack). Also check out eBay. I bought 3 or 4 for about  a fiver.

Wire: Any thin wire will do really.

A small strong magnet: As strong as you can find. The stronger it is the louder the output!!

In the first picture above you can see inside the relay. The left side of the relay is the part we're interested in, the coil. This will be the main part of our pickup. 
The second picture shows what most relays will look like on the board.    

Step 2: Cutting Out the Coil

Picture of Cutting Out the Coil

As I said before it's the coil we're after. This can be tricky to get to without damaging the wiring inside!

First of all we need to identify the pins we'll be using as outputs for our pickup. This will be the two, as shown above, which will be on their own away from the main cluster of pins. You need to be careful with these two pins. 

Depending on the way you're relay has been produced will determine how to proceed.
If the relay, as above, had a cover with clips simply remove the cover.
If it's glued, using a knife remove the top of the relay. This will make it easier to cut away the sides without damaging the components within.

I then carefully used a hack saw to cut the relay in half.

Once you have done this you can remove the thin metal cover over the top of the coil. This is the part that moves up and down when the electromagnet is switched on/off. Do not try to remove the centre core of the coil.

You're coil should now look a little like picture 2 above. Do not remove the pins attached to the coil. These pins are attached to either end of the coil and make it much easier to wire it to the audio jack.

Step 3: Magnifying the Coil

Picture of Magnifying the Coil

For this stage simply put the magnet at the bottom of the coil.

Step 4: Wiring

Picture of Wiring

This stage is very simple too. Just wire the positive and negative from the jack to the coil and you're sorted!

Naturally you can add other components to the circuit so that volume, tone etc. can be varied. However this instructable just covers the basic pickup.

This is the pickup I used in my One Stringed Music Stick instructable (https://www.instructables.com/id/One-Stringed-Music-Stick/.)

Comments

VAustin89 (author)2012-06-14

now you have given me the idea, what if we could wire 6 of this in series and make it a conventional guitar pick up.

Toms Workshop (author)VAustin892012-06-15

Go for it! Should work. Just a single one produces a pretty decent sound so six in series should be awesome!

VAustin89 (author)Toms Workshop2012-06-15

How much is the DC resistance of one "pole"? since most single coil pick-up would be around 5K ohms. I am still searching through my old stuff looking for some relay switches

Toms Workshop (author)VAustin892012-06-15

Sorry man, I don't know. The coil is now inside the One Stringed Music Stick I made so I'm not sure I'll be able to test it. Sorry.

This is a good one for noodling on a single string instrument -

You may well be better off finding really big coils from old transformers and doing something like this:
https://www.instructables.com/id/Make-A-Guitar-Pick...
If you wanted to make a pickup for a 6-string.


wobbler (author)Toms Workshop2012-06-18

Regarding coil ohms, I'm going to try making one using these as they are cheap enough:
http://www.maplin.co.uk/pcb-mount-low-profile-10a-relays-2512

The specs give the different version coils driver voltages and resistances as:
6v coils 100ohms
12v coils 400ohms
24v coils 1600ohms
It looks like, the higher the coil voltage, the greater the number of turns and hence resistance.

I'm planning on using two on a two string guitar set up as a humbucker pair with one for each string, but I can't tell you if it works yet as I've not yet bought the relays so I can't check if they pull apart easily. I'll get back to you when I've tried it!

Toms Workshop (author)wobbler2012-06-19

Sounds awesome! Let me know how it goes. It'd be good to see some pictures of the final product :-)

sarawkar (author)VAustin892012-09-29

dude attach them in parallel....or most of your signals might get cancelled out....

yapoyo (author)2012-10-26

My band director is always yelling at me for not having a tuner pickup. Could I hook this to a tuner?

QuinnH (author)yapoyo2015-03-19

If you play anything other than a steel stringed instrument (electric or acoustic guitar), this will not work. It is not a contact microphone like what you would clip onto a trumpet's bell.

Toms Workshop (author)yapoyo2013-03-09

►Sorry for the late reply. Yeah, can't see why not :-)

Toms Workshop (author)2012-08-09

Sorry man, only works with metal strings. Needs metal to interfere with the magnet, creating the signal. If you were to use metal strings the pickup could be placed inside the soundbox between the soundhole and the bridge. If you want to electrify the ukulele with nylon strings I'd recommend looking at piezo electric pickups.
Here's an example on eBay: http://www.ebay.co.uk/itm/Twin-Piezo-Pickup-for-Cigar-Box-Guitar-Stomp-Box-20mm-/180944604828?pt=UK_Guitar_Accessories&hash=item2a21238e9c

About This Instructable

28,954views

111favorites

License:

Bio: I am a Mechanical Engineer who loves making random things!
More by Toms Workshop:Snake DidgeridooPrescription Sunglasses. Under $36 (£25)!One Stringed Music Stick
Add instructable to: