< img height="1" width="1" style="display:none" src="https://www.facebook.com/tr?id=1724791474554128&ev=PageView&noscript=1" />

Audio Amplifier PCB: The Ultimate FAQ Guide


If you want the best audio signals, you need high quality audio amplifier.

A reason this guide will answer all your questions about audio amplifier.

Whether you want to learn about audio amplifier PCB layout, design, material or features, you will find all information right here.

So, keep reading to learn more.

What Is An Audio Amplifier PCB?

This is a board that you will use to amplify audio signals from systems that you will send to speakers, radio receivers, etc.

Besides, it assists in improving input signals that you feed in the PCB.

An Audio Amplifier PCB
An Audio Amplifier PCB

What Features Should Audio Amplifier PCBs Have?

These printed circuit boards have the following traits:

High Input Impedance

This trait is suitable for input signals to make the voltage drop across the amplifier.

Low input impedance causes no voltage drop on the amplifier, hence, receives no signal.

This effect is the reason why you should construct the input with low impedance materials.

Also, high input impedance prevents loading as low input impedance draws current in large amounts.

This effect causes the load to build on the circuit.

Besides, this design will minimize noise within the PCB.

High Open-loop Gain

This is the capability of the audio amplifier PCB to increase the amplitude or the power of the signal.

When no feedback is within the circuit, you can measure high open-loop gain between input and output ports.

High open-loop gains can accomplish several levels of feedback and can achieve a suitable performance level.

Limited Bandwidth

The design of the audio amplifier PCB should have a suitable bandwidth that accommodates the frequency it amplifies.

A narrow bandwidth may cause some loss of signal frequency while a broad bandwidth may introduce noise in the circuit.

Low Output Impedance

Audio amplifier PCBs amplify signals once you drop the voltage across it.

Therefore, speakers should have high impedance than the output of the audio amplifier PCB.

Low output impedance causes the voltage to drop on the speakers.

What Are The Guidelines When Making A Layout For Audio Amplifier PCB?

These guidelines entail the following:

Power Plane

Installation of power planes should be thick to enhance supply to the pin for it to increase the limit.

Besides, take caution when many ICs within the exchange chain supply the power plane.

A good design entails planes connecting to ICs in star-connection configurations from the main power supply.

This will minimize negative effects on subsequent ICs due to high switching on the ICs within a similar line.

Bypass transistors will assist in immediate switching current wants and detach voltage noise disturbance within control pins.

This effect produces a stable and steady power supply which enhances efficiency.

Place convergence capacitors close to pins on top layers and use thick traces to lower routing resistance and redundant inductors.

Route decoupling capacitors after the top layer to lower parasitic effect on the internal pins.

Ground Connections

Ensure the ground pins should be close to the ground plane and short the unit grounds to avoid shaping many ground loops.

Also, it is suitable to directly connect unit pads and ground planes.

Position Of Capacitor

Place capacitors close to pins on the upper layer to avoid spurious inductors.

Switching current needs causes resistors and inductors to overshoot or undershoot the voltage spike.

The voltage will surge due to the swapping of current in the power supply and inductors can lead to large voltage ripples and stop system functions.

To minimize parasitic inductance and resistance, use the shortest resistance for the diverging routes.

Output Signals

There is a minimum width of 30 mils between each layer of Class-D output signals.

Ensure you have a 60 mils path between output and speakers in EM applications.

Also, you need to place EMI filters close to unit pins.

Match the length of output signals to prevent discrepancies due to differences in routing resistance.

Signal Switching

To prevent coupling and interference, Class-D output, SW node, and signals continually swap signals that you should redirect.

Also, do not route these signals in similar layers unless you have ground protection between the two layers.

Charge Pump Capacitor

There should be as little parasitic inductance and resistance between GREG or VREG and PVDD pins within charge pump capacitors.

Also, connect charge pump capacitors in a star connection format near the PVDD pins and not PVDD planes.

Apply thick routing immediately on top layers to minimize parasitic within this pin for signal routing.

Digital Format Signals

It is vital to route digital signals in a certain way to prevent them from conflicting with other signals.

Also, do not connect them to swapping nets as they can lead to digital signals pairing and injecting noise.

A Layout Of An Audio Amplifier PCB
A Layout Of An Audio Amplifier PCB

What Are The Mechanical Properties Of Audio Amplifier PCB?

The mechanical properties entail the following


This is the measurement of the density of dielectric materials’ in audio amplifier PCBs [g/cc or lb/in3]

Time To Delamination

It is the time it takes dielectric materials of audio amplifier PCBs to resist delaminate-causing effects.

It illustrates the time the layers within the board require to separate due to temperature changes.

Thermal shock or moisture causes the laminate or glass in the audio amplifier PCB to delaminate.

Peel Strength

This is the ability of audio amplifier PCBs copper and dielectric layers to bond.

Flexural Strength

This is the capability of dielectric materials’ in audio amplifier PCBs to not break when you apply physical stress.

This test happens by applying force at the centre of the audio amplifier PCB while supporting the ends.

What Should You Consider When Selecting The Parts Of An Audio Amplifier PCB?

These include:


This is important during the entire phase involving drawing the schematics.

Take into consideration the following:

  1. Connection of the parts
  2. Pins and outlines
  3. Housing and packing restriction
  4. Top and bottom sides of the PCB
  5. The height clearance for polarized capacitors

Grounding Practice

Designing a suitable grounding system needs planning from the conception of the design process.

Ensure you have suitable amounts of ground planes and bypass capacitors.

Besides, decoupling capacitors are vital near the supply to the ground location.

The advantages of ground planes include:

  1. Shielding circuit from the noise that can radiate from the lower section of the PCB
  2. Increasing mechanical strength of the PCB
  3. Provide easier routing of the circuit
  4. The addition of distribution capacitance thus minimize noise
  5. Allows you to lower impedance in the PCB thus lowering interference and noise

Assign Virtual Components

It is important to design BOM [Bill of Materials] then analyze the virtual audio amplifier PCB parts within the design.

Replace the parts within the virtual section that contain footprints.

Spare Gates

To prevent spare gates from floating, connect them to signals via their input.

This is important since floating inputs interfere with the operations of the audio amplifier PCB.

Reference Designators

Ensure you continuously number the reference designators as it helps you with sorting and reviewing the BOM information.

Bill of Materials [BOM] data

Ensure you review the Bill of Materials to get data that will assist you to decide on the number of parts you need for the PCB.

Make necessary adjustments if you have incomplete components and then relay the information to your vendor or supplier.

General PCB Layout Consisting of Core , Prepreg and Thin Copper Layers
General PCB Layout Consisting of Core , Prepreg and Thin Copper Layers

How Do Small Signal Audio Amplifier PCB And Large Signal Audio Amplifier PCB Compare?

Here is how these two compare:

Small Signal Audio Amplifier PCB

This PCB is suitable for amplifying low-level audio signals from a stereo.

Besides, they perform this task without altering waveform guidelines such as signal shape and frequencies.

They are also known as “voltage” amplifiers as they convert voltage from a small input to a larger output.

Their application entail microphones, ultrasonic transducers, etc.

Besides, they have thin copper wires since they need high impedance.

A Small Audio Amplifier Ready to Be Connected for Use
A Small Audio Amplifier Ready to Be Connected for Use

Large Signal Audio Amplifier PCB

They are also known as “power” amplifiers as they send power to loudspeakers, motors, etc.

Besides, they alter the DC power to AC voltage signal.

They also have thick copper wires to penetrate the high value of current to flow.

audio amplifier PBCs
A Loudspeaker That Receives Power from Large Signal Audio Amplifier PCB

What Are The Advantages Of Audio Amplifier PCB Layout?

There are various classes of audio amplifier PCBs, and they have different benefits depending on the layout:

Class A

This class offers better stability within the frequency and the feedback loops.

Besides, it is easy to make as it requires minimum part count and single-device parts.

Class A Audio Amplifier PCB
Class A Audio Amplifier PCB

Class B

This class has two active devices that transmit half of the original half-cycle hence offer total current to drive the load.

Therefore, class B audio amplifier PCB layout has a higher efficiency rate.

Class AB

This class eliminates cross-over distortion, known as the alternate approach.

Class C

They have higher frequencies than classes A, B, and AB and rely on radio frequency usages to have 80% efficiency.

Class AB Audio Amplifier PCB
Class AB Audio Amplifier PCB

What Is Stray Capacitance In Audio Amplifier PCB?

Surplus, undesirable, inescapable capacitance that occurs in high voltage systems is known as stray capacitance.

It comes about due to their parallel configuration or due to environmental interactions.

In higher frequency audio amplifier PCBs, stray capacitance may merge with stray inductance.

What Should You Consider When Choosing Laminates For Audio Amplifier PCB?

These include:

  • Loss factor
  • Dielectric constant
  • Electrical performance
  • Thermal conductivity
  • Coefficient of thermal expansion
  • Transition temperature
  • Ability to function in various thermal environments

How Do Audio Amplifier PCBs Maintain Thermal Stability?

An Image Illustrating How Heats Dissipates From a PCB
An Image Illustrating How Heat Is Dissipated From A PCB

Maintaining thermal stability is vital for audio amplifier PCBs as it prevents the failure of electronic circuits.

Audio amplifier PCBs accomplish this effect by continuously dissipating heat and the dissipation level depends on parts.

This entails traits of copper such as thickness and the surface area, and the thickness and materials that make up the PCB.

Besides, narrow and thin materials dissipate less heat than broad and thick materials.

Also, product specification can affect the heat dissipation level as dissipation can happen through radiation or convection.

Aluminum heat sinks are suitable for hotter parts within the PCB.

Some audio amplifier PCBs use different combinations such as horizontal or vertical thermal conduction.

Horizontal thermal conduction happens via copper surfaces while vertical thermal conduction happens through thermal vias.

Also, you can strategically place heat sinks in audio amplifier PCBs to assist in heat dissipation.

Copper planes on audio amplifier PCBs also assist in spreading heat and perform horizontal thermal conduction.

Besides, thermal vias will create a small path of thermal resistance from the upper copper plane to the lower side of the board.

In this design, you employ heat sinks to the lower part of the copper planes to assist in dissipating heat to the atmosphere.

What Are The Limitations Of Audio Amplifier PCB Layout?

The need for regular soldering when removing and replacing the output parts happen when you incorrectly install audio amplifier PCB traces.

Such actions may destroy the components or the structure of the audio amplifier PCB.

Incorrectly fitting heat sinks can cause overheating hence making output devices becoming hot.

This is despite them having good scores as audio amplifier PCBs as they produce more current.

What Are The Thermal Properties Of Audio Amplifier PCB?

The thermal properties entail the following:

Thermal Conductivity k [W/m]

This defines how fast heat moves within an audio amplifier PCB.

Insulators have a minimal thermal conductivity than conductors.

Coefficient Of Thermal Expansion CTE [ppm]

This is the rate at which audio amplifier PCBs will expand when you subject them to heat.

Ensure CTE is as low as can be.

Decomposition Temperature Td [°C]

This is the temperature that causes substrates in audio amplifier PCBs to permanently decay.

Decomposition temperature should be lower than solder mask temperature.

Glass Transition Temperature Tg [°C]

This is the temperature that will soften audio amplifier PCBs.

The solder mask temperature should be higher than the glass transition temperature.

Which Materials Are Suitable For Making Audio Amplifier PCBs?

The PCB materials you choose depend on how they operate, their traits, and their effect on the performance of the audio amplifier PCB.

Also, you can gauge the traits of these parts depending on their dielectric constant.

Besides, the cost and effectiveness of these materials range from FR-4to PTFE [polytetrafluoroethylene].

New technology has developed thermoset-resin dielectric materials and the material you select should properly handle temperature affects dielectric constant.

Besides, FR-4 is popular with audio amplifier PCBs and they can also withstand damage from heat.

Some materials you can use include:

  • PTFE
  • Alumina
  • Kapton
  • Substrates falling between FR-1 and G-10
A Treble Board That Possess a FR-4 Audio Amplifier PCB
A Treble Board That Possess a FR-4 Audio Amplifier PCB

What Process Can You Use To Test The Quality Of Audio Amplifier PCBs?

ATG test devices and grid testing functionalities can assist you to test the quality of audio amplifier PCBs using the following criterion:

  • The capability of fabricating them into circuits with a steady impedance
  • Ability to manage steady dielectric constant with temperature variations
  • Energy loss due to dissipation should be low to make sure you have minimal power output loss and signal gain
  • The capacity to manage the heat it generates by power audio amplifier PCBs through CTE and conductivity

What Is The Layout Of An Audio Amplifier PCB?

A PCB builder makes graphic drawings of copper wires on the audio amplifier PCB layout.

This mechanism enables audio amplifier PCBs to enhance input signals that load in it by transforming analog signals to digital signals.

After amplification, microprocessors analyze then generate output signals.

What Are The Various Types Of Audio Amplifier PCB Layouts?

There are several audio amplifier PCB layouts and they fall into the following classes:

Class A Audio Amplifier PCB

It contains high linearity and gain, with a conduction angle of 360 degrees, and a single transistor that always remains ON.

Class B Audio Amplifier PCB

It contains two active devices and enables you to bias signals in sinusoidal waves one-by-one.

Class C Audio Amplifier PCB

This board operates in turned and unturned operating modes.

The conduction angle is below 180 degrees hence has an efficiency of between 60% and 70%.

Class AB Audio Amplifier PCB

This class overcomes cross-over distortion.

Class D Audio Amplifier PCB

It is a switching audio amplifier PCB using pulse width modulation.

Class E Audio Amplifier PCB

It is highly effective, applies switching typology, and operates in radio frequencies.

Class F Audio Amplifier PCB

It has high impedance mostly to harmonics, and sine and square waves can drive it.

Class G Audio Amplifier PCB

They use rail switching units to enhance efficiency and minimize power consumption.

Class H Audio Amplifier PCB

It is an enhanced version of PCG audio amplifier PCB layouts.

Do Audio Amplifier PCBs Have An Offset Voltage?

Correcting input signals to achieve zero volts on the output of audio amplifier PCBs is known as offset voltage.

Besides, you will measure offset voltage in DC voltage.

Zero voltage on the input side does not mean zero voltage on the output of the audio amplifier PCB.

This is due to fluctuations and imbalances within the internal circuit unit.

Therefore, adjusting the input assists you receive zero voltage at the output of the audio amplifier PCB.

Input offset is the magnitude of the modification or correction you require.

The range of the offset voltage depends on the specifications of the board.

What Are The Applications Of Audio Amplifier PCBs?

Audio amplifier PCBs operate in various systems as they assist in converting analog signals to digital signals.

They find their application in:

  • Stereo systems
  • TV audio
  • Headphones
  • PC audio
  • Automotive audio, etc.
A PC Amplifier
A PC Amplifier

What Are The Specifications Of Audio Amplifier PCBs?

The following factors assist in specifying audio amplifier PCBs:

  • Pin connections
  • Electrical ratings of the supply voltage and input voltage
  • Applications such as HI-FI systems, split power supply, single power supply
  • The type of class such as class A, B, AB, etc.
  • Electrical traits such as supply voltage, Quiescent drain current, power bandwidth, and input bias current

How Does An Audio Amplifier PCB and Normal PCB Compare?

Here is how the two compare:

Normal PCB

Here, you can mount components using thru-hole technology of surface mount technology.

The physical nature of the board, such as its length and thickness determines other factors such as the resistance of the PCB.

Also, you can manually design normal PCBs using Photomasks.

This entails placing transparent Mylar sheets and make traces using adhesive tapes.

Double Sided  2- Layer PCB made from FR-4
Double Sided  2- Layer PCB made from FR-4

Audio Amplifier PCB

Here, you will fabricate the board using schematic capture, and then design and position the parts using the software.

The complexity of the audio amplifier PCB determines the physical characteristics, such as length and thickness, of the board.

Geometric and thermal factors are vital when placing components on the board.

Besides, the resistance of transistors will influence the power output and input.

Audio amplifier PCBs are superior to normal PCBs.

What Types Of Laminates Can You Use With Audio Amplifier PCB?

Selecting the right laminate influences stability, performance, power loss, and assembly of the audio amplifier PCB.

The laminates you can use include:


This is the most popular laminate for use in surface mount assembly.

FR4 has a good strength-to-weight ratio, mechanical, physical, and electrical characteristics.

Besides, it is flame resistant.

A FR4 Laminate
FR4 Laminate

BT Epoxy

This laminate has high thermal resistance, mechanical, and electrical traits.

Besides, BT epoxy is suitable for lead-free audio amplifier PCB assembly and multilayer systems.

It maintains the bond at high temperatures, has high electromigration, thermal, and insulation resistance.

High Tg Epoxy

This laminate is excellent for multilayer audio amplifier PCBs.

It offers superior chemical and thermal resistance and is versatile, flame resistant, and cost-effective.

Besides, it operates effectively in application with high humidity and temperatures.


This laminate has high circuit trace adhesion toughness and is stable in extreme environments.

Besides, they are suitable for producing highly dense audio amplifier PCBs.

Also, they have suitable thermal, mechanical, and thermal properties.

A PCB Made From Polyamide
A PCB Made from Polyamide/Polyimide

How Does Power Audio Amplifier PCB And Voltage Audio Amplifier PCB Compare?

Voltage audio amplifier PCBs will amplify the input voltage to a high voltage, hence are manufactured with the operational audio amplifier circuits.

Power audio amplifier PCBs are suitable for circuits with parts requiring higher switching currents.

These parts include loudspeakers and motors.

Besides, both power and voltage audio amplifier PCBs have input and output terminals.

Also, they will apply small input signals to produce higher output signals.

A Power Audio Amplifier PCB
A Power Audio Amplifier PCB

What Is The Purpose Of A Heat Sink In An Audio Amplifier PCB?

Heat sinks assist in dissipating heat when the audio amplifier PCB is operating.

Besides, aluminum material is suitable since it has high conductivity levels and can resist corrosion and abrasion.

It operates with the assistance of copper traces and thermovia and the operational principle includes radiation, conduction, and convection.

What Are The Chemical Properties Of Audio Amplifier PCBs?

The chemical properties include:

Flammability Specifications [UL94]

The Standard for Safety of Flammability of Plastic Materials for Parts in Devices and Appliances [UL94] will rate the flame-retardant characteristics of plastics.

It illustrates the need for materials to combust for less than 10 seconds with flaming combustion.

Methylene Chloride Resistance [MCR]

This is the capability of audio amplifier PCBs to defy chemicals that checks the resistance of dielectrics to methylene chloride absorption.

Dielectrics have an MCR of between 0.01% and 0.20%.

Moisture Absorption

This is the capacity of audio amplifier PCBs dielectric materials to repel moisture when in the presence of liquids.

Most audio amplifier PCB materials contain moisture absorption of between 0.01% and 0.20%.

How Can You Incorporate Heat Sinks In Audio Amplifier PCBs?

The following parts can assist you to incorporate heatsinks in audio amplifier PCBs:

  • Solder pins
  • Shur-lock tabs
  • Solderable mounting tabs
  • Thermal clips
  • Male and female mounts
  • Device mounting studs
  • Solderable staked on tabs
  • Tapes
  • Kool clips
  • Clinch nuts
  • Solderable nuts

What Is The Purpose Of Applying Conductive Silicon Grease On Audio Amplifier PCBs?

Conductive silicon grease enhances heat radiation since you will apply it to the heat sink of power transistors and diode bridges.

Besides, then servicing, ensure the following:

  • Evenly apply silicon grease on the surface of heat sinks
  • Tighten screws securely
  • Ensure radiation fins have no contaminant between it
  • Eliminate original paste before applying silicon grease

How Do Audio Amplifier PCB And Power Amplifier PCB Compare?

Audio amplifier PCBs alter audio signals while power amplifier PCBs change the voltage input from small to large.

They will both convert DC to AC.

The power output of audio amplifier PCBs is lower AT 14W, while that of power amplifier PCBs is high, at 2000W.

Audio amplifier PCBs dissipate less heat than power amplifiers since they have small transistors.

The collector load of power amplifier PCBs has low resistance with a thick base to accommodate for high current flow.

Audio amplifier PCBs have high resistance collector loads and thin bases to accommodate for low current.

Do You Need Transistors In Audio Amplifier PCBs?

Transistors take a small amount of current at one end, then produce a high current on the other end.

Here are some benefits of using transistors in audio amplifier PCBs:


Transistors are continually being smaller thus you can use them in audio amplifier PCBs


Transistors find their applications in electronic devices that require impact resistance and can function in extreme environments.


Transistors will produce less heat hence you can use them in audio amplifier PCBs and experience no overheating.


Transistors are small and lightweight thus suitable for small devices.

Power Consumption

Transistors consume less power making them convenient for low-power devices.

This effect makes it suitable since you need not worry about the battery or power draining.

How Can You Minimize Voltage Drift In Audio Amplifier PCBs?

Temperature stability can cause voltage drift of bridge components hence, use materials with the lowest temperature coefficient on audio amplifier PCBs.

The parasitic thermocouple can contact bridge components and activate voltage drift hence, use like materials or materials whose thermoelectric voltage is low.

Also, employ low thermoelectric voltage soldering alloy to make these connections.

Use zero-drift amplifiers if the thermal direction of zero indicator amplifiers causes voltage drift.

Also, you can combat this effect by using a chopper stabilizer.

What Are The Electrical Properties Of Audio Amplifier PCBs?

The electrical properties entail:

Volume Resistivity [ρ]

This is the ability of audio amplifier PCB dielectric materials to resist electricity or insulation.

Dissipation Factor/Dielectric Loss Tangent [Tan δ/Df]

Audio amplifier PCBs lose less power if the loss tangent is low.

Relative Permittivity/Dielectric Constant [Dk/Er]

Signal integrity and impedance will impact the electrical performance of audio amplifier PCB dielectric materials.

Electrical Strength

This is the ability of audio amplifier PCBs to resist electrical disruption in the Z direction.

Surface Resistivity [ρS]

This is the resistance audio amplifier PCB dielectric materials to electricity and insulation.

How Many Layers Do Audio Amplifier PCBs Come In?

They can come as:

  • Single-sided audio amplifier PCB containing a single layer
  • Double-sided audio amplifier PCB containing two layers
  • Multi-layer audio amplifier PCB containing more than two layers

What Is Operational Audio Amplifier PCB?

This is a signal conditioning device that filters out noise and amplifies electrical signals.

How Much Leakage Resistance Do Audio Amplifier PCBs Offer?

Leakage resistance is the assertive static circuit board due to contaminants on the surface of the PCB.

Contaminants may include debris, flux residue, and salts which cause leakage of current to occur within the board.

Minimize leakage by cleaning the PCB or using well-designed guards.

Which Software Can You Use To Design The Layout Of Audio Amplifier PCBs?

They entail the following:


It is open-source software that runs on Windows PC.


It assists in designing specialized audio amplifier PCBs with a maximum of 800 pins.

Eagle PCB

It provides 3D design.

Osmond PCB

It is flexible and can design any board size, with several parts and numerous layers.


It is simple to operate, runs on various computer software, and includes BOM, 3D visualization, and Gerber file.


It has rule checks and PCB level analysis.


Suitable for automatic electronic design and liked by technicians and electronic design engineers.


Suitable for designing simple PCBs that contain four modules and runs on all computer software.

Can You Drill Audio Amplifier PCBs?

Drilling processes entail using laser processing and machining.

Ensure you etch the audio amplifier PCB with mechanical tools when using drilling machines as it marks the drilling locations.

Finally, fit it in the machine and proceed with the drilling process.

How Do Rigid, Rigid-flex, And Flex Audio Amplifier PCBs Compare?

Rigid-flex audio amplifier PCBs are a hybrid between rigid and flexible PCBs and you can continuously flex or fold when operating.

Flexible audio amplifier PCBs can bend since they are on flexible substrates.

Rigid audio amplifier PCBs cannot bend or fold as they are on a rigid substrate.

How Can You Fabricate Audio Amplifier PCBs?

Fabrication of audio amplifier PCBs entail the following:

  • Using software to design the PCB
  • Produce films that will assist you in printing an image on a plastic board
  • Choose raw materials for your application
  • Prepare drilling holes
  • Apply the image using printers, pen plotters, or dry transfer
  • Strip and etch to eliminate unwired coper using chemicals such as ferric chloride
  • Test the PCB to ensure it is functional

For all your audio amplifier PCB, Venture Electronics guarantees high performance printed circuit boards.

Contact us today for any inquiries on audio amplifier PCBs.

Recent Posts
Contact Us
Send A Message