Shielding.
Let's start with how to properly shield your guitar.
In general, most decent electric guitars have a factory shielding made in the form of graphite varnish or EMILAC (varnish with copper powder). This gives good signal protection against interference and noise.
It looks like this:
If you don’t have a screen of this type, you can always make it yourself by replacing graphite with an aluminum cooking tray, aluminum or copper tape.
Main screening errors:
- the use of completely unsuitable materials (candy wrapper, other non-conductive surfaces, foil glued to superglue, etc.).
- Extremely careless execution. In this case, the screen can simply be closed with a signal wire or other parts of the circuit.
- Shielding where you do not need to do this. Only shielded rations and unshielded wires need to be shielded. The screen should not lie on wires or anywhere else, just under the timbral block.
A shielded wire, like a capacitor, has a certain capacitance, since the signal wire runs parallel to the screen. Because of this stray capacitance, low frequencies disappear (the smaller the capacity of the overall screen, the cleaner the sound). In order to avoid such an effect, when soldering the timbroblock, an unshielded signal wire must be used.
The voice block cover must also be covered with a screen. When shielding, one should not allow large gaps or gaps, since the screen is a shell that takes over all the interference. It is necessary to make sure that the joints of the aluminum adhesive tape not only fit tightly against each other, but also have contact (if the adhesive layer on the adhesive tape does not give normal contact, then you can solder it using a special flux for brazing aluminum).If the timbral block is mounted on a pickguard, then only this part can be covered with a screen.
And what is a timbral block?
At its core, the guitar timbral block is a special switching circuit that is located inside the body of a musical instrument.
In the tone block, the signal from the pickup hits the sensor switch (volume), volume, tone and output jack.
At its core, the screen in the timbre block is a continuation of the screen in the signal cable.
Let's move on to the wiring of the electric guitar itself.
You can find your wiring diagram here on this site:
And I will show how this is done with me:
In this scheme, there are two potentiometers for 500 kom, a three-position switch, a jack jack 6.3 mm. Between the contact of the tone potentiometer and the common minus is a capacitor of 47 nF and 100 volts. It is needed to filter high frequencies.
It should be noted that when soldering, it is necessary to remove signal wires from the screen as much as possible, and earth loops should not be allowed.
“- this is the unevenness of the land, in other words - different potentials at the grounding points of the power cables of two or more devices (units inside the device), sometimes - grounded screens. Well, where there is a potential difference - there is respectively voltage and current (spurious), the appearance of which is expressed in noise and constant interference. ”
The bottom line is that all the disadvantages of the circuit are reduced exactly to one point and contact the screen only at this point. Thus, the voltage coming from the screen in the form of a spurious signal will not mix with the useful signal.
This desoldering method is called star wiring:
In my case, the cons from the whole circuit are reduced to one point - the volume potentiometer, where they are in contact with the screen.
Here I talked about the basic intricacies of wiring and shielding an electric guitar. And remember, it will turn out crooked by itself, so if you want to do it right, you need to work hard.