Why doesn’t the TV show an exact volume level?

When using the VMA00102 or AX130, you can adjust the volume with the TV remote control. Depending on the TV model, however, the TV may not display a fixed numeric volume value such as “Volume 25”. Instead, you may only see + and – symbols or a simple volume bar.

This is not a fault of the VMA00102 or AX130. It is a result of how this type of volume control works technically. The AX130 and VMA00102 work in a similar way. The AX130 additionally provides a Toslink output, also known as an optical digital audio output. This output is digital and does not have adjustable volume. This means that pressing “Volume +” on the TV remote will not change the volume of a device connected to the optical output. The volume adjustment only affects the analog audio outputs.

Why does the TV show a number when using its own speakers?

When you use the TV’s built-in speakers, the TV knows its own internal volume setting exactly. For example, it knows whether the current setting is “20”, “35” or “50”.

This is why it can display this value on the screen.

A similar situation can occur with an HDMI soundbar. If the TV and soundbar exchange volume information via HDMI-CEC, the TV may also be able to display a specific volume value.

With the VMA00102 or AX130, the situation is different.

What happens when using the VMA00102 or AX130?

The VMA00102 receives the TV audio via HDMI ARC and then outputs it through another audio connection, for example:

• analog to a stereo system,
• analog to headphones or a headphone amplifier,
• digitally via Toslink to an audio system with the AX130.

The TV can send commands such as

“Volume up”

or

“Volume down”

to the VMA00102 or AX130.

The device then increases or decreases its analog output level.

However, the TV does not know a corresponding absolute volume value. For this reason, many TVs only display + or – in this operating mode. This is normal and technically correct.

There may be two independent volume controls

This is an especially important point:

If you connect a stereo system, amplifier or headphone amplifier to the VMA00102 or AX130, there are often two separate volume controls.

1. Volume controlled by the TV

Using the TV remote control, you adjust the analog output level of the VMA00102 or AX130.

If you press “Volume up”, the device increases its analog audio output level.

If you press “Volume down”, the output level is reduced.

2. Volume controlled by the connected audio device

Your stereo system, amplifier, active speakers or headphone amplifier may also have its own volume control.

This volume setting is completely independent of the TV.

For example:

The TV and VMA00102 may provide a relatively high output level, while the volume control on your stereo system is set relatively low. This setup will normally provide the best sound quality.

Or the opposite may be the case:

The output level of the VMA00102 is set quite low, while the amplifier is turned up significantly.

The actual sound level you hear therefore depends on the combination of both settings.

Why can’t the TV display the “real” volume?

The TV only knows that you have sent a command such as “increase volume”.

It does not know how loud the connected audio device is actually set.

For example, the TV cannot determine:

• the volume setting of your stereo system,
• how far a headphone amplifier is turned up,
• the sensitivity of your headphones or speakers,
• the actual acoustic volume being produced.

The VMA00102 and AX130 cannot know these values either.

A display such as “Volume 30” would therefore only be a value chosen by the TV. It would not represent the actual listening volume of your stereo system, headphones or speakers.

Why do some TVs still display a numeric value?

The volume display is controlled entirely by the TV.

Depending on the manufacturer and TV model, the TV may display:

• a numeric value,
• a volume bar,
• only + and –,
• a speaker icon,
• or simply a short message indicating that the volume is being changed.

The VMA00102 and AX130 have no influence on how the TV displays this information.

The numeric range can also vary from one TV to another. One TV may use a scale from 0 to 100, while another may use a different scale or no numbers at all.

Important note about the AX130 optical output

The Toslink output of the AX130 is a digital audio output with a fixed level.

This means that the TV remote control does not adjust the volume of the Toslink output.

If your audio system is connected via Toslink, the listening volume must therefore normally be adjusted on the connected amplifier, sound system or other audio device.

The adjustable volume function of the AX130 applies only to its analog outputs.

The key point

If the volume of the analog outputs can be increased and decreased with the TV remote control, the volume control of the VMA00102 or AX130 is working correctly.

If the TV displays only + and – instead of a fixed numeric value, this is normal.

The TV only knows that a volume command has been sent. It cannot know the actual listening volume of your stereo system, headphones or other connected audio equipment.