Handcrafted basses

ELECTRONICS

How do you connect the pickups and controls? I will not go into active pickups here because pre-amps and equalizers are used on those. A lot of electronics, endless possibillities to create different sounds. It would be too much for this site, so I limit myself to some passive circuits. For those who like to build a pre-amp, equalizer or effect pedals, check out www.epanorama.net, you can find a lot of circuit diagrams there.

Here are some diagrams. The pickups you see are normal single-coils and humbuckers, not the active ones. Especially for basses: it's worth experimenting with the values of the capacitor. The 100nF capacitor you see below in the pictures, cuts a large part of high frequencies.
This is a basic circuit for 1 single coil pickup, no matter bass or guitar.


You can experiment with the value of the capacitor. Try some lower values like 22n, you may like what you hear. I build a switch in one of my basses so I can select two different values. With this feature, I get the sound of the Rickenbacker 4000 series bassguitar (with an accent on the hi-mid frequencyrange).
This is the same circuit, but with an additional tone selector.


Using more than one pickup results usually in having a switch between the pickups and volume control to select a pickup or combination.
This is a circuit for 2 single-coil pickups with a switch to select PU 1 or PU 2 (not both)


Instead of a pickup selector switch, you can choose to have a separate volume control for each pickup, so that you can mix the sound better.
This is a circuit for 2 single-coil pickups with seperate volume controls.


There is no difference in Volume and tone controls when a humbucker is applied. Added is a switch, wich can select 1 or 2 coils of the humbucker. Switching one coil off causes the humbucker to act as a single coil pickup, with a different sound of course.
A circuit with 1 humbucker and 1 single-coil pickup, with a single/dual switch for the humbucker.


If you have 2 or more pickups, it is possible to change the polarity of one of the pickups. The pickup is out of phase, and this gives you a different sound, mostly a "squawking" type sound, like if a phaser effect is used. You can also use a polarity switch on a humbucker wich acts (and in fact is) as two single-coil pickups close together.
A partial circuit with a single coil pickup and polarity switch.


With the above circuits you should be able to wire up other combinations as well, like 2 or 3 humbuckers, 1 humbucker and 2 single-coils, etc. I have tried several combinations with all the switching possibillities you can have. Sometimes with dissappointing results, when you hardly could hear the difference when a switch was used. If you're not certain of the effect of switches or volumecontrols: don't drill the holes yet. Try the circuit unmounted if you can. When using 1 or 2 pickups the circuit is fairly straightforward, but if you want the full range of sounds with 2 single-coils and a humbucker (I did) you'll find yourself putting 3 volume controls, tone controls, and at least 5 switches on your guitar. Ah, wanna play stereo? No problem, make it a few switches more. Just kiddin', don't do this! You'll find out that you don't use most of the controls anyway, so try to keep it functional.


A Groundwire attached to the bridge.
It is possible to reduce noise some more by connecting a groundwire from the electronics to the bridge. This way, when you touch the strings, your body acts as ground and the annoying sounds are gone.

This used to be common practice until some years ago. The big disadvantage: when you're playing you are connected to the electronics of your guitar, and via the cable to the ground of the amplifier. When your amp has bad ground (or not at all), due to a bad or ungrounded walloutlet, a malfunction in the amp or an open air concert in the rain, you could end up with a short circuit and 110 or 240 volts on your strings. After some guitarplayers died because of this, it is forbidden for manufacturers to connect a groundwire to the bridge. Try to reduce noise by shielding your pickups and electronics compartiment. If you decide to make this connection on your own guitar: IT'S AT YOUR OWN RISK!! I take no responsibillity for the consequences when you do this.


Next page: Let's go on to the last part of guitarbuilding: tuning and ajdusting the guitar. On to the TUNING page.