Electricity

If it converts an AC voltage to an identical AC voltage, it is called an

Isolation Transformer.

Ground Loops

Leakage currents - Negative feedback • Pin one (audio ground) lift

Electro-Motive Force

Measured in VOLTS (V) • Similar to pressure • Basic unit to measure potential differences

Open Switch

Off - No path for current to flow.

Closed Switch

On - Completes path for current flow.

The formula used to determine the power output of a power amp is

P=IxE

Power

Power is the rate at which energy is converted or consumed in an electrical circuit. • Power is measured in watts • The schematic name for power is the letter "P"

Voltage =?

Pressure

If you are trouble shooting what are the steps in order

Read, Is it plugged in, is it turned up, is it turned on

Headroom

Reserve Power or voltage gain in an amplifier gain stage.

if current goes down what goes up

Resistance

what is R

Resistance/ measured in ohm's

The output side of a transformer is called the

Secondary winding

If it converts an AC voltage to a lower AC voltage, it is called a

Step Down Transformer.

If it converts the AC voltage to a higher AC voltage, it is called a

Step-Up Transformer

the Two Basic Types of Transformers

Step-up / Step-down transformers and Unity 1:1. Impedance, and isolation

T/F: in a parallel circuit, the total resistance of the circuit is always lower than the smallest Branch Resistance In the Circuit.

TRUE

The purpose of impedance matching

maximizing power transfer, maximizing efficiency, and max. headroom

What is P

power, measured in Watts

Primary Winding

the input side of a transformer

Wiring

• Low value of R = Better conductor, more current will flow • Big wire = Low R (Z) better flow • Small wire = Higher R (Z) constricted flow

• Power = Current • Voltage

• P = I • E • I = P / E • E = P / I

Load Resistance

• Resistance in a circuit • Current does not have to flow for EMF to exist • Example: a 120V AC wall outlet

A preamp has blank voltage gain compared the voltage gain in a power amp

a higher

In the US, the voltage between the hot and neutral terminal of an AC outlet should

120 VAC

In the US, if you measure the voltage between the hot and ground wires on an AC outlet, what should the voltage measure?

120 Volts AC

In the US, the voltage between the hot and neutral terminal of an AC outlet should measure

120 Volts AC

Electro-Magnetic Induction

A coil of wire moving through a magnetic field (or a magnetic field moving past a coil of wire) will induce or generate an AC current into the coil of wire. Also, an AC current flowing through a wire will generate changing magnetic flux lines that emanate out from the wire.

A preamp has blank voltage gain compared the voltage gain in a power amp.

A higher

Conductor

A material that allows for the free flow of electrons. It "conducts" electricity. Electrons flow through a conductor with very little opposition or resistance

In a series circuit:

A. voltage will drop across each resistor B. you add up the resistor values in the circuit to determine the total resistance. C. the amount of current flowing would be the same through all resistors And....the there is one path for current to flow CorrectYes that is correct. There is one path for current to flow. Voltage drops across each resistor and the current remains constant.

Differences between AC and DC

AC volts have frequency, phase and amplitude DC volts have amplitude

The unit of measurement used for Current is

Amps

Open Circuit

An incomplete path resulting in no current flow. Example: A broken wire.

Short Circuit

An incorrect path for current to flow. Example: Two wires touching that aren't supposed to be connected

A Blank cable has the best noise rejection and cancellation?

Balanced

What is I

Current, measured in Amps

Hertz

Cycles Per Second(cps) - Also known as frequency

If resistance increases and voltage remains constant, the current will

Decreases

Clipping

Distortion of an audio signal caused by exceeding the limits of a particular amplifier gain stage

Devices that use Electro-magnetic induction are

Dynamic mics, X-Frmrs, Speakers, Turntables, Tape heads,

Voltage = Current • Resistance

E = I • R - Volts=Amps • Ω

T/F: AC and DC have a constant, non-changing polarity.

False

True/False: A shorter thicker wire will usually have more resistance than a wire that is longer?

False

Clipping cont

Generation of Odd Harmonics • at Amplifier Stage and Speaker Level • Generation of heat in speaker coil - Destruction of speaker by under powering

Maximum Power Transfer

Getting the most efficient use from an amplifier

Concept of Ground

Ground is the Zero (0) Volt reference point in a circuit. • Often a chassis is connected to earth ground. • The chassis of a piece of equipment is similar to the chassis of a car.

If voltage increases and resistance remains constant, the current will

Increase

if you needed to lower the resistance in a circuit you could:

add another resistor in a parallel Branch

What is E

The voltage, measured in Volts

If you need to lower the resistance in a circuit you could...

add another resistor in a parallel branch

A transformer converts AC voltage & current to another AC voltage and current.

True

Mic to Line Level is Most Important in determining Signal to Noise Ratio - (S/N)

True

T/F: A microphone Transduces sound into AC voltage.

True

T/F: In a parallel circuit the total current is the sum of the individual branch currents.

True

True/False: a dynamic mic works on the principle of electromagnetic induction.

True

True/ False: DC volts have amplitude

True!

t/F Voltage can be described as the pressure that causes current to flow.

True!

All wires have some resistance (R)

True: - Longer wires = Greater R - Shorter wire = Smaller R - Thinner wire = Greater R - Fatter Wire = Smaller R

3 Things to measure with a multimeter

Voltage, Current, Resistance (VCR)

What are the most important things to know about troubleshooting a problem with a piece of equipment?

What the manual says, How the equipment works

a balanced cable has the best noise rejection and cancellation.

YES!

a power supply converts Ac to DC

YES!

transformers

convert AC voltage and current to another AC voltage and current. BLOCK DC voltage!

If resistance increases and voltage remains constant, the current will..

decrease