Lesson 2: Basic Electronics - Posted on 2016-09-13 by Nicolas Schilke

BASIC ELECTRONICS.

Second lesson at The Lair Studio with my mentor, Larry Goetz. On this second lesson we covered basic electronics.

The primary electronic measurements are voltage, current and resistance:

• Voltage: measured in volts (V), refers to the amount of electromotive force.
• Current: measured in amperes (amp), is the amount of electric charge passing through a specific point per unit of time.
• Resistance: measured in Ohms (Ω), is the amount of electric impedance.

In terms of material we can distinguish between two types:

1. Insolators: these materials have a tight atomic structure and don't lose electrons easily, impeding the flow of electricity (rubber).
2. Conductors: these materials easily lose electrons, favoring the flow of electricity. The most frequent materials used in wire are gold, silver, copper and nickel. Copper (the most common) has a tendency to corrode while the rest don't corrode very easily.

Wires are what conduct electricity from one places to another. The thicker the wire (gauge), the more conductive it is. The longer the wire,  the more voltage loss (audio loss). For these reasons, the shorter and thicker wires are the better.

Coils and Magnets

Everything in audio is magnetism. Electricity is generated by running wire through a magnetic field. This has a certain frequency that can be translated to sound. Pickups work this way. The more windings if wire the more high frequency loss.

*Single coil guitar pickup.

The lower the resistance on a speaker, the more current can pass through. The more current it has, the louder the speaker.

Two coils close enough to each other can still run electricity between them. This is how transformers work. If there is a difference on each coil's winding, the resulting voltage may either increase or decrease.

AC and DC current:

Direct current (DC) has a single direction of electric flow translating into a flat constant frequencie whereas alternating current (AC) has a flow of electric charge that periodically reverses direction. Rectifiers are electrical devices that convert AC to DC. All electronic devices require DC, so rectifiers are used inside the power supplies of all electronic equipment.

*AC current (top) and rectified AC current (bottom).

After explaining all of this to me, Larry taught me some interesting stuff such as:

• You want to have the closest input resistance to your outputs resistance, if so, you get a flatter signal.
• Metal placed inside vacuum tubes amplify you audio. The typical vacuum tube is anywhere between 300 and 500 watts.