Just in time for the Pono II with tube amplifier!I was always under the impression that people went solid state due to the difference in transformer size and weight. As well in things like TVs there always seemed to be one wearing out and solid state was more reliable and needed less calibration. With solid state shipping is less of an issue to your retailer, most TV retailers would test delivered sets in house and install and calibrate you set up till the days of solid state.I also collect smaller portable transistor and tube radios from the 50's - 60's. They made smaller lower power tubes for portable radios but transistor won out due to less expense of production, better economy on the battery and being able to be made into a smaller (cute-r) size and perhaps shock resistance.This hopeful will provide some of advantages of both tubes sound quality and solid state smaller power requirements and such. Although the people seem to think that the plate voltage somehow is vital in the sound and how tubes react to signal. But it is sure cool that Korg would come up with something new they seem to be innovating all around.

I had always heard that late period tube nuvistor development was military based as consumer stuff had moved to solid state. That the military needed stuff that could withstand EMF blast and tubes could but they found other tech that could work at a certain point.The Nutube design looks pretty wild square what looks like light points... like a display tech.

this is a pretty weird development. small, flat, solderable tubes? might be cool.http://www.korg.com/us/news/2015/012207/

I am really curious about this. I have actually worked with a group that built nanoscale etched vacuum field emission triodes. They used doped diamond which had a low work function in order to minimize extractor voltage.In my previous job in electron emission devices I designed and built a field effect triode using a carbon emitter and it was lovely. And cheap. It was done in a small vacuum chamber at about 2x10-7 Torr, which would be pretty hard to replicate in an enclosed environment using only a getter. But I would still like to try it one of these days. I always wanted to built a standardized dual triode using this configuration, if possible. The issues of needing a high vacuum and degradation of the emitter due to sputtering would have to be overcome but it would be a fun project if I had the equipment. Maybe one of these days.Jon

The text of the Press posting;2015.01.21KORG INC and Noritake Co., Limited Release Innovative Vacuum Tube: the NutubeKORG INC and Noritake Co., Limited are proud to announce the successful development of the ground breaking technology, Nutube, a new miniaturized and high performance tube. In cooperation with Noritake Itron Corporation, KORG INC. has developed the Nutube to offer incredible reliability and efficiency while still generating the same rich harmonics which vacuum tubes are known for. The Nutube 6P1 featuring this innovation will be on display at the Korg USA Winter NAMM Booth.KORG has used vacuum tubes for many years in products such as VOX-branded guitar amps and effect units, KORG-branded dance/DJ products such as the electribe MX/SX and keyboards such as the SV-1. Vacuum tubes have played a major role in shaping the sound of VOX and KORG products, and have been a crucial element in their distinctive character.As with previous vacuum tubes, this newly-developed Nutube is structured with an anode, grid, and filament, and operates as a complete triode tube, generating the same rich harmonics that are distinctive of conventional vacuum tubes. By applying technology from Noritake Co., Limited's vacuum fluorescent displays, the structure of the vacuum tube has been modified, dramatically reducing its size and allowing it to consume less power. Production is carried out at the cutting-edge Japanese production facility of Noritake Itron, a subsidiary of Noritake Co., Limited., significantly raising the product quality in comparison to previous vacuum tubes by boasting the following features: Power Consumption. Miniaturization dramatically reduces power consumption, allowing the Nutube to operate using less than 2% of power required by conventional vacuum tubes and making it easy to power the unit on batteries. Compact. The Nutube occupies less than 30% of the volume of a conventional vacuum tube. Its small size and low thermal output allows it to be easily mounted directly on a high-density circuit board without using a socket High reliability and long life. The unique design and state of the art Japanese production facility ensures the Nutubes are built to the highest standard and offer up to 30,000 hours of continuous operating life. The high reliability means that it can be attached directly to the circuit board with confidence knowing that it will not need to be replaced regularly like a 12AX7."As an electronic component, a vacuum tube has the disadvantages of being larger than a transistor, having a shorter lifespan, and a higher power consumption, and although many people like the sound of a vacuum tube, historically they have been more difficult to deal with, stated Fumio Mieda, KORG INC s longstanding developer who was involved in numerous KORG synthesizers including the MS-20 which appeared in 1978. œThe Nutube sets us free from these many limitations, making it possible for us to think about using it in new products, added Mieda.Most manufacturers stopped producing vacuum tubes in the 1970s and there haven t been any notable advances in the field during the past fifty years. However, thanks to the Nutube 6P1, it is now easier to obtain a vacuum tube sound when amplifying musical instruments and other audio signals.Noritake Itron Corporation, a group company of Noritake Co., Limited, pioneers of vacuum florescent displays says œBy creating a miniaturized and high performance replacement for traditional vacuum tubes, Noritake Co. Limited expects products using the Nutube will create a renewed appreciation for the inherent qualities of vacuum tubes amongst users. The Nutube 6P1, currently being developed, takes advantage of KORG's experience in musical instrument production, and is tuned for optimal effect to generate rich harmonics when used with a musical instrument. Products using the Nutube are currently under development, with announcements expected during 2015.(Patent applied for.) If you enlarge the picture you will see what appears to be a filament that goes across the middle connected to the two end bars.The korg site I think has a lot of flash or some kind of rather over the top coding so that some people just get the black and it does not resolve into the page. So I have re posted here.

This is pretty interesting. I'd be interested to know how they sound. Presumably only suitable for small signals.

Biggest problem with nuvistors in audio circuits was that the parts were so close to each other inside each tube that it was nearly impossible for them to be rigidly secured enough, meaning that nuvistors used in high gain circuits were universally microphonic. There were a bunch of ridiculous shock-mounting techniques used but it was a major design hurdle and rendered them useless in some applications.The MR70 tape machines had a good reputation for sound quality but they didn't become standards and remain in service the way the warhorse 350s, 351s and later transistor machines did.I heard from some people more deeply into it than me that there was some work done on potential "solid state" vacuum devices, where tiny triodes could be built in layers through etching and then encased in an evacuated capsule, but I don't know any more than that. It would certainly be possible to use an emissive material that required little or no thermal excitation but then you'd have a radioactive doo-dad in your hifi. Them's the breaks.

I can't see anything but a black page when I click the link so I don't know what it says, but I'm intrigued that it's a directly-heated cathode/emitting filament. There has long been a preference in critical circles for directly-heated triodes in hifi power amps, and I've been curious to try some of these "bright emitter" designs for guitar but haven't had the opportunity. I'd love to hear some small signal devices like microphones and preamps using them. Maybe I'll get the chance.