# Audio Electronics (Quiz #1)

The Music Telegraph | Text 2019/06/03 [13:12]

# Audio Electronics (Quiz #1)

The Music Telegraph| 입력 : 2019/06/03 [13:12]

Common Resistor values (band 1 ~ 3)

0 Black

1 Brown

2 Red

3 Orange

4 Yellow

5 Green

6 Blue

7 Violet

8 Gray

9 White

gold .1

silver .01

Tolerance +/- %

20 no band

10 silver

5 gold

Common Resistor color bands and what each position means -

What is its resistance value? __________

What is its tolerance? _______

Precision Resistor Values (bands 1 ~ 4)

0 Back

1 Brown

2 Red

3 Orange

4 Yellow

5 Green

6 Blue

7 Violet

8 Gray

9 White

gold .1

silver .01

Tolerance

1 brown

2 red

3 orange

10 silver

5 gold

Precision Resistor color bands and what each position means -

What is its resistance value? _______

What is its tolerance? _______

The top row of a patchbay jackfield is for __________

The bottom row of a patchbay jackfield is for_________

When patching into the top row of a 1/2 - normal patch point, the signal Does/Does not go to the patch point directly underneath. (Circle one)

When patching into the top row of a Full - normal patch point, the signal Does/Does not go to the patch point directly underneath. (Circle one)

An Independent Patch point os typically used for 2 things:

______________

_______________

Mults are multiple patch points wired in ______ so that the signal from one patch is available on all the other patch points in that MULT

The 3 rules for a Series Circuit

Current ___________________________________________

To get total Resistance ________________________________________

Volts ______________________________________________

The 3 rules for a Parallel Circuit

Current _____________________________________________

To get total Resistance _____________________________________

Total resistance is always ___________ than the smallest resistor

Volts ________________________________

What is the total resistance of this series circuit below? __________________

Show the IR voltage drop for each resistor. Show your work.

Bonus

Use the Voltage Division formula for the same circuit. Don’t have to figure Current.

What is the total resistance for this parallel circuit below? __________

Show the current for each individual branch.

What is the total current for the above parallel circuit? _______

What does Unity Gain mean? _______________________________

Impedance Bridging means __________________________________________

Balanced lines have _____ signal leads and a shield

Unbalanced lines have _____ signal lead and a shield

The 3 signal levels of Pro Audio are

____________, ________________, and _______________ level

Standard Operating level is:

________dBv = ____dBVU = _______volts.

0 dBv=________volts

*Reference Formulas:

Ohm’s Law

V = A x R

A = V / R

R = V / A

Series Resistance

R = R1 + R2 + R3 +etc. = total sum

Parallel resistance (reciprocate the reciprocals)

R = 1/R1 + 1/R2 + 1/R3 etc. added

Then: 1/sum of above = total resistance

Power formulas

P=I x E

P = E^2/R

P = I^2 /R

Wavelength

W = velocity/frequency = 1130 (ft per sec)/1000 Hz = 1.13 ft

dB Watts

10xlog(E1/E0)

dBu, dBv, dBSPL

20xlog(E1/E0)

Voltage drop for series resistance

(I x R) + (I x R) + (I x R) etc. =

Bel

Decibel

dBm

dBu

dBv

dBV

-------------------------

2300Ω = 2.3kΩ

5%

647kΩ

1%

Output

Input

Does

Does not

Outboard gears

Tie lines

Parallel

Same everywhere based on resistances

Drop after resistor from total source of voltages to 0 voltage

Total = 1/1/R1 + 1/R2 + 1/R3 + etc = reciprocate then plus, then finally reciprocate the results again.

Less

Same in every branch

Rtot = R1 + R2 = 4Ω

I = 10V/4Ω = 5/2 = 2.5A. Therefore in R2, IxR2 = 2.5 x 2Ω= 5 volts drop. (E2=5 volts)

Since R1 = R2, I x R1=5 volts (E1=5 volts) drop. (Etotal = E1(=IR1) + E2(=IR2) = 5 + 5 = 10V)

Ei = Etotal(Ri / Rtotal) (i, positive integer, = 1, 2, 3, …)

so, since Total = 10V, Rtotal = 4Ω, therefore E1 = 10 x (2/4) = 5V

similarly, E2 = 10 x (2/4) = 5V

1/1/100 + 1/10 = 1/11/100 = 100/11 = 9.0909…=9.09

therefore, 9.09 Ω

I1 = E/R1 = 10/100 = 0.1A

I2 = E/R2 = 10/10 = 1 A

Itotal = I1 + I2 = 1.1A or Etotal/Rtotal = 10V/9.09Ω = 1.1A

Output = Input in every gain stage

Input impedance is always at least 10 times higher than Output’s

2

1

Mic, Line and Speaker

+4, 0, 1,23

0.775

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