How Does Sound Work in a Classic Arcade Game? PCB, Amplifier, and Speaker Explained

By HighScoreSaves Technical Team

Reviewed and updated August 23, 2026

The sounds of a classic arcade game may appear simple from outside the cabinet, but producing those sounds can involve several parts of the machine.

The exact design varies considerably by manufacturer, game, and era. Some games generate relatively simple tones using dedicated circuitry. Others use processors, sound-generating ICs, ROM data, digital-to-analog conversion, analog amplification, or separate sound boards.

Understanding the basic signal path can make sound problems much easier to approach logically.

Where Does Arcade Game Sound Start?

Sound generally originates from circuitry associated with the game hardware rather than from the speaker itself.

Depending on the game, the system may use:

• the main CPU;
• a dedicated sound CPU;
• sound-related ROM data;
• programmable sound-generator ICs;
• digital-to-analog circuitry;
• analog tone-generating circuits;
• an amplifier; and
• one or more speakers.

Not every game uses every one of these elements.

What Is the Basic Arcade Audio Signal Path?

A simplified audio path can be thought of as:

Game Logic / Sound Circuitry → Audio Signal → Amplification → Cabinet Wiring → Speaker

The real circuit may contain many additional stages, but this model is useful because it demonstrates an important troubleshooting principle:

There are multiple places where arcade sound can fail.

What Does the CPU Have to Do With Arcade Sound?

In many games, program execution determines when a sound should occur.

For example, gameplay logic may determine that a shot was fired, an enemy was destroyed, a bonus was awarded, or a new level began. The hardware then causes the appropriate sound system to respond.

Some games use the main processor for portions of this work, while others have separate sound processors or additional circuitry.

For a broader explanation of the processor's role, see What Does the CPU Do on a Classic Arcade PCB?.

What Do Sound ROMs Do?

Some arcade hardware stores sound-related program instructions or audio data in ROM devices.

The exact purpose depends on the system. A ROM may contain program code used by a sound processor, data used to produce particular sounds, or other information required by the audio subsystem.

That does not mean every arcade sound is simply a prerecorded audio file being played from a ROM. Classic arcade sound architectures vary widely.

Our Original Arcade ROMs Explained article provides more background on the different roles ROM devices can have.

What Is an Arcade Sound CPU?

Some arcade systems use a dedicated processor for sound-related tasks.

The main game hardware can communicate that a particular event occurred, while the sound subsystem handles the instructions needed to generate the corresponding audio.

This division of work can make the sound system partly independent from the main game logic, although the two still need to communicate correctly.

What Does the Arcade Audio Amplifier Do?

The audio signal generated by game circuitry may not be suitable for directly driving a cabinet speaker.

An amplifier increases the signal to a level capable of producing useful sound through the speaker.

Depending on the game, amplification may be located:

• on the main arcade PCB;
• on a separate sound board;
• on another amplifier board or module; or
• elsewhere in the cabinet's audio system.

The amplifier also requires correct power and ground connections to operate properly.

How Does Sound Reach the Speaker?

After the required sound generation and amplification, the audio signal travels through cabinet wiring to the speaker.

Depending on the cabinet and hardware, that path can include PCB headers, edge connectors, harness connectors, adapters, terminal connections, and other wiring.

A poor connection anywhere in that path can affect sound.

For games using edge connections, see Arcade Edge Connectors Explained.

How Does JAMMA Carry Arcade Audio?

JAMMA standardized many common cabinet connections, including power, controls, video, and audio-related connections for compatible hardware.

However, not every arcade game is JAMMA, and not every later game fits completely within the basic JAMMA standard. Dedicated pre-JAMMA hardware can use manufacturer-specific connectors and wiring.

An adapter can also sit between a dedicated PCB and a JAMMA-wired cabinet.

See What Is a JAMMA Arcade PCB? JAMMA vs. Pre-JAMMA Classic Arcade Hardware for the broader wiring distinction.

Are Classic Arcade Games Mono or Stereo?

Many classic arcade games use mono audio, but arcade hardware is not universally mono.

Later and more complex systems may provide stereo or additional audio arrangements. The correct speaker configuration depends on the specific game hardware and cabinet.

Never assume that speaker wiring from one game is electrically appropriate for another solely because both cabinets contain arcade PCBs.

Why Does an Arcade Game Have No Sound?

A no-sound condition can have many possible causes, including:

• incorrect game or operator settings;
• failed or missing sound-related ROMs;
• sound-processor problems;
• audio-circuit faults;
• amplifier problems;
• incorrect or missing supply voltage;
• damaged edge connectors or harness connections;
• broken or disconnected speaker wiring;
• a damaged speaker; or
• previous PCB or cabinet modifications.

This is why replacing the speaker should not automatically be the first response to a silent game.

Why Is Arcade Sound Distorted or Too Quiet?

Distortion or low volume can also originate at several points in the audio path.

Possible areas to investigate include the volume control, amplifier, power supply, connectors, wiring, speaker, grounding, and sound-generation circuitry.

A fault earlier in the signal path can reach the speaker as distorted audio even when the speaker itself is operating normally.

Can the Power Supply Affect Arcade Sound?

Yes. Sound circuitry and amplifiers require appropriate power.

If a required supply voltage is missing, low, unstable, or affected by excessive voltage drop, audio operation can be affected.

Voltage requirements vary by game, so measurements should be compared with the documentation for the actual hardware.

Our Classic Arcade Power Supplies Explained guide covers +5V, +12V, ground, and voltage drop in greater detail.

Can Test Mode Help Troubleshoot Arcade Sound?

Yes, when the game provides an appropriate sound test.

A diagnostic menu may allow particular effects, tones, or music to be triggered directly. This can help determine whether at least portions of the audio system respond without requiring the event to occur during normal gameplay.

However, the available diagnostic functions vary by game.

See Why Does a Classic Arcade Game Have Test Mode and Service Mode?.

Can Attract Mode Sound Be Turned Off?

On some games, yes.

Classic arcade games may provide an operator setting controlling whether sounds play during attract mode. The setting may be controlled by DIP switches, software configuration, or another game-specific method.

A cabinet that is silent during attract mode can therefore be operating exactly as configured even though sound works normally during gameplay.

Read What Is Attract Mode on a Classic Arcade Game? for more about idle game behavior.

Why You Should Identify the PCB Before Troubleshooting Sound

The same game title can sometimes exist on different board revisions, conversions, bootlegs, reproductions, or replacement hardware.

Sound circuitry, connector pinouts, component locations, and troubleshooting procedures may therefore differ.

Before relying on a schematic or replacing components, identify the actual hardware in the cabinet. Use our original arcade PCB identification guide as a starting point.

Key Takeaway

Classic arcade sound is a signal path rather than a single component. Game logic and sound circuitry create the required audio information, amplification increases the signal when needed, and cabinet wiring carries it to the speaker.

Because CPUs, ROMs, sound chips, amplifiers, power, connectors, wiring, settings, and speakers can all be involved, a silent or distorted arcade game should be diagnosed systematically rather than assuming the speaker is defective.

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Classic Arcade • Modern Features