Noritake Introduce Futuristic Nutube Vacuum Tubes

[Nick]

http://www.synthtopia.com/content/2015/01/29/korg-noritake-introduce-futuristic-nutube-vacuum-tubes/

Many of us will have used Noritake VFDs, and as any fule kno, VFDs can be used as triodes, so maybe Noritake decided to cash in on this or just try to see where it'll end up.

They've called it the "Nutube 6P1" (*)

The VFD heritage is obvious for all to see - basically, they seem to have been able to use exactly the same manufacturing technology, specifically in the use of new long-life cathode coatings, and also the same form factor & encapsulation as a traditional VFD. Great idea.

They're claiming 30,000 hours of continuous use, only 2% of the power consumption of a traditional triode (e.g. 12AX7) and very small size - 30% of the size of a "conventional vacuum tube", however big that might be. Also claiming "rich in harmonics"...

Homepage: [url]http://www.korg.com/us/news/2015/012212/[/url]

Can't find a datasheet ATM.

Sounds fun... and its not even April 1st :)

The anode fluorescence is due to this really being a VFD, made on a VFD production line, by a company that makes most of the world's VFDs :)

The anode coating of VFDs is what makes VFDs so useful, but its not essential (just cool). The cathode coating, OTOH, is vital - VFD manufacturers have developed coatings that make the cathodes perform flawlessly for many years - at least 3.5 years (30,000 hours) of continuous running - old purpose-built triodes like the 12AX7, used to need replacing fairly often, with lifespans of less than 10,000 hours. 

So, to save money, Noritake have used a standard VFD production line to do this - VFD form-factor, VFD internal construction, VFD anodes, grids & cathodes, VFD pin-outs etc. etc. 

Pretty much any VFD can be used as a triode, some even up to RF frequencies...

Sensible move, really...

(*) for some reason originally I read that as "Nut Lube" :shock:

[David Forbes]

Nick,

Nice find! This is a clever repurposing of existing manufacturing mojo.

I'd still like to se the Nuvistor resurrected. It had the unfortunate problem of
being introduced at exactly the wrong time.

[Mark Moulding]

Many of us will have used Noritake VFDs, and as any fule kno, VFDs can be used as triodes, so maybe Noritake decided to cash in on this or just try to see where it'll end up.

They've called it the "Nutube 6P1" (*)

The VFD heritage is obvious for all to see - basically, they seem to have been able to use exactly the same manufacturing technology, specifically in the use of new long-life cathode coatings, and also the same form factor & encapsulation as a traditional VFD. Great idea.

Check out the DM-160 digital indicator DM-160 datasheet (pdf). There's also a Russian cold-war-era equivalent: the IV-15.  These are both available on eBay.  I played with them a bit, setting it up as a triode amplifier, and it did in fact work; also, the display portion very nicely followed the audio signal.  I didn't work too hard at it, but in my initial experiments the gain was quite low - amplification factor of 15 or so.  however, I was running in a starved-plate mode; I suspect that with the recommended plate voltage and some experimentation with the plate resistor, it might be a reasonable amplification stage.
~~
Mark Moulding