Few of the high-end audio manufacturer are finally starting to implement this very intriguing "tube", with the expectancy of 30.000+ hours. It would be interesting to see few implementations where usual opamps are taking place...

Nutube, similar to a conventional vacuum tube, has an anode grid filament structure, and operates exactly as a triode vacuum tube. Also similar to a vacuum tube, it creates the same characteristic rich overtones. By applying their vacuum fluorescent display technology, Noritake Itron Corp., a Noritake Co. Ltd affiliated company, have devised a structure which achieves substantial power saving, miniaturization, and quality improvements when compared with a conventional vacuum tube.

Realising substantial power savings

By making the form smaller we have succeeded in making significant power savings requiring less than 2% of the electrical power of a conventional tube. This allows for efficient and simple battery operation.

Small size

Nutube is less than 30% of the size of a conventional vacuum tube.

Real vacuum tube sound

The real triode structure produces a warm, unique vacuum tube sound, delivering excellent linearity.

High reliability, long life

Made in Japan. 30,000 hours of continuous life expectancy


Q. What led the company to develop Nutube?
A. The manufacturing equipment that is currently used to produce traditional vacuum tubes for the company has been used for over fifty years. Therefore, the vacuum tubes that are being produced with this equipment contain many defective units as well as significant characteristic variations. They also consume a lot of power. So we decided to apply all the latest technologies that are available to us and developed ‘Nutube’ – a high quality and battery-operable vacuum tube that is energy-efficient and can be handled with ease – hoping that this novel vacuum tube would bring performance and satisfaction to more people.

Q. How much power supply voltage is required to properly operate the product?

A. The operating voltage is from 5V to 80V. Please see the datasheet for more details.

Q. Can it replace a standard 12AX7 tube? Are they interchangeable?

A. As the power supply voltage and pin assignments are different between this product and a 12AX7, they cannot be used interchangeably.

Q. What are the voltage and current of the heater?
A. 0.7V and 17mA for each channel. Please see the datasheet for more details.

Q. Why is the directly-heated type tube used instead of indirectly-heated one?
A. We decided to adopt the directly-heated type tube as it significantly reduces power consumption and also suppresses heat generation.

Q. Can the Nutube be affected by vibrations (i.e., microphonics)?
A. Yes, as the Nutube is a directly-heated type tube, it can be affected by vibrations. Suppressing the microphonic effect can be done more easily than with a conventional vacuum tube, as ‘Nutube’ does not generate heat.
We are also planning on offering accessories that can be used to suppress any microphonic effect.

Q. Why does the Nutube have such a unique shape while a conventional vacuum tube is usually round-shaped?
A. This unique shape is a result of the product adopting Noritake Itron Corporation’s vacuum fluorescent display (“VFD”) technology. With the application of this technology, we have been able to achieve higher product quality and longer service life compared to conventional vacuum tubes.

Q. How can a VFD be modified and turned into a vacuum tube?
A. Unfortunately we are unable to answer this question as it involves various patent issues.

Q. How long is the typical service life of the Nutube? What does the term ‘expected service life’ (as mentioned in the product catalogue) mean?
A. The expected service life of the Nutube when used continuously is 30,000 hours. The term ‘expected service life’ means the number of hours for which the Nutube will likely be able to operate continuously under normal use.

Q. What kind of sound does Nutube produce?
A. It emits sound that is similar to the sound made a conventional vacuum tube. If you would like to learn more about the characteristics of Nutube, please refer to the datasheet provided. We will be also offering sample boards for evaluation purposes.