• straditube@.com

How it all began

The premium vacuum tube manufacturer, ZeroMountain Company was founded in December 2018, with production in Republic of Korea.
In Korea, vacuum tubes were mainly used in electronic devices such as TV, radio etc and it gradually disappeared from the late 1960s.
ZeroMountain company is the only one in Korea that designs and manufactures vacuum tubes for audio.

Our brand name is StradiTube.
Stradi comes from Antonio Stradivarius, the name of an italian string instrument master in 1700's. Until now, he is famous as a string instrument maker.

We like classical stringed instruments such as violin, cello etc. While traveling in Cremona, Italy, we heard the sounds of many stringed instruments and talked about the way how they were made. After that, we thought we wanted to make stringed instruments, but in reality, we decided to produce vacuum tubes for audio that are most familiar to our university major.

What makes our tubes special?

We have features that set us apart from other vacuum tube companies.
All of these features were developed by us through performance tuning.
Here are some of the features.

First, Ladder-type Frame Grid

We use framegrid structure, which minimizes microphonic, noise and creates a clean sound quality.
The framegrid we use is a ladder type, which is a modified version of the old style framegrid. Although the ladder type framegrid is expensive to manufacture with a high level of difficulties, it is strong against vibration(microphonics) and has the advantage of producing clearer sound.

Second, Minimize Filament End-loss

We applied structures that can reduce the end-loss of the filament. This reduces sound distortion and provides a very natural, clean sound. You can see this by glowing at the top of the filament when the vacuum tube is running.

Third, Electrophoresis for Filament Coating

We use electrophoresis filament coating method. The uniformly coated filament maintains a uniform temperature throughout the filament's entire range , reducing distortion of the sound.

Fourth, Triple Mica

In the past, Triple Mica was mainly used in high-reliability tubes, and the main purpose of using this structure was to serve as a shield to prevent the inside of the vacuum tube (cage) from being contaminated when a getter flash explodes within the vacuum tube.
StradiTube, however, was designed and applied with the deliberate purpose of reducing microphonics using the Triple Mica structure.
To put it simply, StradiTube's Triple Mica is used in a completely different purpose from its past use in order to create clearer and more natural sound quality without vibration.

Fifth, Dual Getters

The vacuum tube getter absorbs gasses generated when the vacuum tube operates and plays a role in maintaining the internal vacuum level stably.
In the case of a getter, the more a vacuum tube is used, the more the area of the getter mirror gradually decreases.
If the remaining part of the mirror becomes very small or disappears, the vacuum tube can no longer be used.
StradiTube uses dual getters to double the area of the getter mirror, slowing down the rate at which the mirror area gradually disappears, thereby overcoming the disadvantage of not being able to use a vacuum tube due to the getter.

Sixth, Ultra High-Vacuum Tubes

Our tubes are made with Ultra High Vacuum (~10E–⁹) using a state-of-the-art turbo pumping system with getters. The higher the vacuum, the less distortion, resulting in a clearer sound and tubes' working life extension.

Seventh, Selected Vacuum tubes

After aging in 20 hours, we test individual characteristics of our vacuum tubes according to our quality standards. We provide each tube with a serial number and characteristic data sheet.

Lastly, Eco Friendly Paper Packaging

ESG is a new norm that integrates the individual values of Environmental, Social, Governance. In fact, it is sometimes interpreted by expanding the concept of ‘sustainability’, which means eco-friendliness or green growth, which we are familiar with.
Our company pursues manufacturing processes that are not harmful to humans and nature. Likewise, when providing vacuum tubes to customers, we strive to contribute to green economy activities by providing eco-friendly packaging.
The Stradi tube package box can be disposed of as recycling together without the need to separate the tape and box.
Instead of using white color, the box uses yellow, which is the natural state of paper, and is designed using a single color on the box.
This is because we want to reduce the consumption of water and resources needed to keep our tube boxes clean when they are recycled.
Unlike traditional methods that use sponges or plastic bubble wrap to protect vacuum tubes, we use yellow paper bubbles as is.

Guarantee on Stradi tubes

Guarantee Conditions