If you use high-end vacuum tube audio equipment with open acoustic characteristics,

it will inevitably be much more sensitive to unwanted noise caused by surrounding electronic devices and power quality compared to transistor-based audio equipment.

Apollon Audio’s reference products are highly susceptible to stress from irregular noise or hum (interference).

Some users have even given up using vacuum tube audio due to mysterious electromagnetic noise.

Many audio enthusiasts hesitate or delay purchasing vacuum tube audio because electrical noise causes them stress.

Facing noise issues in vacuum tube audio without knowing the cause can become a very frustrating situation.

If you only focus on the drawbacks of vacuum tube audio,

many people prefer transistor audio because there are no special advantages or reasons to choose otherwise.

However, after experiencing the sound of vacuum tube audio for about three months,

even those people conclude that transistor audio sounds dry and mechanical.

This message is for those of you with deep knowledge and insight into music.

If you read and understand this message today, confidently choose Apollon Audio’s reference-grade products—the true high-end audio.

When using Apollon Audio’s reference-grade products, you may be relatively more affected by irregular electromagnetic noise.

Our products are based on incredibly delicate acoustic energy and passionately decode a wide frequency range.

((((How to Solve Harmonic Noise in Vacuum Tube Audio))))

Problem-solving approach:

1) Check if there is a defect in the audio equipment. Turn off the preamp power and turn on the power amp power.

Check for irregular noise or hum and record the noise characteristics of the left and right channels.

Then turn on the preamp power and record whether the noise changes.

Next, turn off the power amp power.

With the preamp power on, cross-connect the preamp’s right output to the left output.

Turn the power amp power back on.

Record changes in noise from the power amp’s right and left speakers and note your observations.

2) Be sure to unplug the power cords of electronic devices equipped with AI functions.

(For example: electronic devices with artificial intelligence, voice recognition, wireless transmission functions, or those that operate by detecting body temperature must have their power cords unplugged.)

Especially for electronic devices with inverter-type power supplies, unplugging the power cord for testing is essential.

Check if noise occurs. If noise is significantly reduced,

Solution: Install voice recognition devices, Wi-Fi wireless transmitters, wireless video transmitters, and other transceivers at least 1 meter away from audio equipment or move them to locations where interference is minimized.

If electronic devices with inverter power supplies are the cause, we recommend repairing or replacing those devices.

((Due to issue #2, irregular noise may occur in one channel during test #1.))

Or if irregular noise occurs in only one channel during test #1,

the cause may be a faulty vacuum tube or poor contact between the vacuum tube and socket.

Be sure to check the condition of the vacuum tubes and the contact between the vacuum tube pins and sockets to resolve the issue.

Most noise is likely generated from vacuum tubes installed in the audio equipment.

If you have the electronic devices mentioned in #2, 99% of the problem is likely caused by those devices.

3) Always unplug the power cords of vintage audio equipment. (Vintage products using power cords with polarity (+), (-) hotline, and neutral line structures must be separately categorized and their power cords unplugged.)

In other words, power cords of products without grounding terminals must be unplugged.

Check if noise occurs.

(We trust you understand the related solutions.)

4) Measure the AC voltage between the grounding side and neutral side of the AC power.

If the AC voltage between the two terminals is below 1V, the grounding is considered normal. If the AC voltage is 2V or higher, priority should be given to installing proper grounding as a solution. (We will separately explain grounding installation methods for 100% bedrock or sandy ground.)

5) Replace your multi-outlet power strip with the most basic product that has a grounding terminal.

Replace the power cable with a standard cable and check for changes in noise. Record the results after checking.

6) Do you have a step-up transformer or a step-down transformer? Be sure to replace it with an isolation transformer.

Using a single-winding transformer in an audio system can cause harmonic noise due to potential differences.

7) Are you using a solar power system? If you are using AC power generated from a solar generator, problems may occur due to generator defects. Test by cutting off the power input from the solar generator.

Or if the solar power system is installed within 10 meters of your home and the neutral line is common, a malfunction in the solar power system’s inverter may be the cause.

By reading and understanding these seven points and approaching the problem accordingly, you can perfectly control noise and hum that occur when enjoying vacuum tube audio.

At Apollon Audio, we guarantee excellent and ultimate sound. However, if problems like the above occur and you have the willingness to identify the cause, we are happy to assist you.

There is no difficulty in solving the problem.

Everyone, do not fear vacuum tube audio. Once you understand it, vacuum tubes are optimized devices for realizing the ultimate sound.

No matter how hard transistor amps try, they cannot match the outstanding sound quality.

Now, do not fear or hesitate—make your choice.