Any good NAMM rumors involving NuTubes?

[BassmanPaul]

Actually, it looks like Vox just announced a 150 watt full nutube amp. This is similar to the prototype I saw a while back.

It may have a nutube in the power amp but it’s a SS output section.

 

[pfschim]

They are real tubes as far as I can tell. Very similar to the old hearing-aid tubes. Just not cylindrical.

I thought they were not vacuum tubes at all, basically a plate of glass glued to a substrate. Upthread Seamonkey posted that they don't use a getter process to purify the vacuum and require a SS devices for input and output to get any useable volume .. which does not at all like a real tube to me - like the ones that any of us can currently buy without any issues at all.
the more I read of these, the more it seems that these are a solution looking for a problem that does not exist.

but, what do I know ?

 

[agedhorse]

From my understanding, they do operate within a vacuum, and they do modulate electron flow using grid potential. It's a bit like a cross between a crude CRT and a triode, except the Nu-Tube removes the CRT portion. IMO it's pretty darn clever, though I don't know how useful considering it's limitations. I do not know how similar their transfer functions are to conventional tubes in overdrive conditions either.

 

[RoadRanger]

Yah - filament, grid, and plate in a vacuum. Invalid Link Removed

From the bad old days before transistors - have fun :
subminiature vacuum tubes | eBay

CK722 Classic Germanium Transistor Website and Museum Photo Gallery Photograph Page3

 

[beans-on-toast]

Microphonics have been a long standing problem with Nutube technology. Their application note (incorporated in the document below) suggests ways of shielding the glass. Seems that they could improve the packaging but I assume that they want to keep it small and light weight.


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[RoadRanger]

Microphonics have been a long standing problem with Nutube technology. Their application note (incorporated in the document below) suggests ways of shielding the glass. Seems that they could improve the packaging but I assume that they want to keep it small and light weight.

I'd guess it is the directly heated filament that's the main issue. Unfortunately indirectly heated filaments or any additional support structure would increase the power draw and heat dissipation .

 

[RoadRanger]

BTW there was once someone on fleaBay selling battery powered onboard preamps using one of those hearing aid tubes .

 

[blubass]

I won't assume anything considering the tone and application of this technology. Either companies utilize it and have competitive products, or they don't.

Either way, sound > speculation every time. I'm anxious to hear where this technology does or doesn't lead to.

 

[seamonkey]

There are some web pages out there with people taking apart old VCR's and re-using the the VFD in audio circuits.
One had some magnets and a coil to make a ring modulator. Magnets affect electron flow. Just like magnets on a CRT.
Korg might have missed out on the opportunity to patent some interactions between transformer coils sitting next to the nu-tube

 

[agedhorse]

Microphonics have been a long standing problem with Nutube technology. Their application note (incorporated in the document below) suggests ways of shielding the glass. Seems that they could improve the packaging but I assume that they want to keep it small and light weight.

I think part of it is due to being directly heated, but part of it us because the filament/cathode is planar, which is much more subject to vibration.

 

[beans-on-toast]

View attachment 2885562

There are some web pages out there with people taking apart old VCR's and re-using the the VFD in audio circuits.
One had some magnets and a coil to make a ring modulator. Magnets affect electron flow. Just like magnets on a CRT.
Korg might have missed out on the opportunity to patent some interactions between transformer coils sitting next to the nu-tube

I sometimes buy test equipment parts from sphere research. They stock nixie and magic eye tubes: [Invalid or Expired Link Removed].

I like the idea of an atomic clock with a nixie display for the time: The most accurate nixie clock

It’s kind of an oddball site but they have some interesting reference material.