11 ms·

Korg NuTube, vacuum tube for the 21st century

168 points by ChuckMcM 8y ago

ChuckMcM 8y ago
These are pretty cool, it is a triode made out of vacuum fluorescent display tech.
- mrandish 8y ago
  Not much of a hardware guy... so what would this be useful for and better at?
  - brian_herman__ 8y ago
    Music uses vacuum tubes due to the sounds that they produce.
  - ChuckMcM 8y ago
    The way the thermal constant works in a tube is unique to its construction. As a result when you saturate an amplifier built with tubes rather than getting square wave clipping (which is full of odd harmonics) you get a modulated overtone. In Music systems this overtone has energy at musically compatible harmonics and so it still sounds good. In radios it can be easier to filter out the spurs (spurious overtones from non-linear operation) without swamping the modulation on the signal.
    - jackhack 8y ago
      translation: "an amplifier that sounds pleasant and warm, not harsh like a transistor."
      - sethhochberg 8y ago
        The thing to note is that (good) tube amplifiers can be designed to be very linear until they're driven too hard - the audiophile community often overlooks this detail when they're shopping for "warm" tube amps for general power amp duties. The big differences between tubes and other kinds of amplifiers appear when they're driven at, and especially past, their design limits. In an application like a guitar amplifier, some kind of effect/distortion pedal, etc the tube circuit is typically overdriven by design to get all of those warm harmonics. A tube that isn't being overdriven is every bit as capable of being a "wire with gain" as any kind of transistor or more modern circuit.
      - blattimwind 8y ago
        Good transistor amplifiers (i.e. 70s technology) are sufficiently good approximations of an ideal audio-band VCVS that they have no sound at all.
        mark-r 8y ago
        I used to think that until I compared a couple. The most realistic sound I've ever heard was from a tube-powered system.
        ferongr 8y ago
        Post your statistically-significant double-blind testing logs.
        Applejinx 8y ago
        You do understand that your point of view is only one among many valid positions on the subject, some held by authoritative figures? (and I don't mean me, I'm thinking the likes of JJ) This isn't solely a defense of the position you challenged, more a call-out on your tactic here. You're not exactly representative. The talk of transistor amplifiers being perfect and having no sound at all is of course nonsense: typically this kind of claim looks at frequency response and outright ignores slew rate, crossover distortion, behavior as the amp exits its passband on either extreme, and so on. There CAN be transistor amplifiers, both simple and incredibly complex, that are so good that they've got effectively no sound at all. It's even possible that it's easier to get there with a transistor amplifier given enough money and resources. But that's not the claim.
        blattimwind 8y ago
        Liking tube sound or, more generally, the defects/characteristics of a particular amplifier (, headphones, speaker, room, ...) is perfectly fine with me. I get easily annoyed though when people start spewing pseudo-scientific BS justifying that deviations are objectively better than no deviations or that there are significant (or "obvious with good ears") differences between amplifiers where there simply are no such differences.
    - tubetime 8y ago
      eventually you do get a square wave (similar to a transistor) but with less overdrive, you get a "soft clip" waveform that is rich in second harmonics. these harmonics are an octave above the fundamental, and can also create a psychoacoustic effect where you hear another sound that is an octave below. bass players LOVE using tube amplifiers for this reason--it really fattens up the sound without making it sound crunchy.
  - aidenn0 8y ago
    A tube amplifier sounds very different when clipping (i.e. try to amplify the signal past the maximum the amplifier can produce), and this is used to create distortion, most notably for electric guitars. There are DSP effects that can simulate this as well, of course.
- tubetime 8y ago
  it works with a regular VFD as well! see https://twitter.com/TubeTimeUS/status/1061797427991068672 https://twitter.com/TubeTimeUS/status/1061797427991068672 for a photo and the resulting waveform.
tlb 8y ago
Here's a project using actual VF display tubes as an amplifier: http://www.hpfriedrichs.com/radioroom/vfd/rr-vfd.htm http://www.hpfriedrichs.com/radioroom/vfd/rr-vfd.htm If you look at the wiggly plate current curves he measured, there should be plenty of harmonic distortion for tube audio enthusiasts. My 1970s HP oscilloscope contains several Nuvistors (https://en.wikipedia.org/wiki/Nuvistor https://en.wikipedia.org/wiki/Nuvistor), which are nearly as small. 17mm x 10mm dia.
- ChuckMcM 8y ago
  Wow, I think that first reference is going to put a crimp in Korg's patent application :-)
  - bayindirh 8y ago
    I think it won't. Because it looks like there's even a magnet on the Korg's tube. They might be leveraged that same research, and listed it as a prior art or paid him as co-inventor.
    - ChuckMcM 8y ago
      The confusing bit for me, and realize I'm not a patent lawyer but have patented a few things, the referenced articles first publication was in 2008. I was told that in the US (but not in Europe) you have one year from public disclosure to file for a patent. (In Europe you give up your patent rights if you disclose first.) So to patent this you'd want to have filed in 2008. Here it is 10 years later. So why hasn't a patent issued? I've seen them take 3 - 5 years but 10 years seems like a stretch.
  - tecleandor 8y ago
    BTW, the VFD used on the first link happens to be Noritake, that is, the same brand associated with work for the NuTube project, and the inventors of the VFDs, so this might not me new for them at all. And also, by the way, almost the only brand still manufacturing VFDs that are easy to find on the market (at least buying one by one). And also, they make pretty tableware :D
cordite 8y ago
Assuming 8 hours of use a day, this would last at least 10 years. Does audio equipment suffer less from the disposable electronics culture that we have with computers?
- bayindirh 8y ago
  I have an AKAI AM-2850 amplifer older than me. Its VU meters a bit lazy, but otherwise it's still shaking the house. I'm no way getting rid of it! P.S.: I generally dispose any of my devices when they let their magic smoke out. Computers stay at least five years and upcycled. Mine -> Family -> Extended family -> so on.
- jdietrich 8y ago
  Computers generally become obsolete at some point. Most audio equipment doesn't - newer equipment might be cheaper, more reliable or more convenient to use, but it probably doesn't sound any better. The cachet and mystique surrounding vintage equipment means that it often appreciates in value with age. Vacuum tubes are considered obsolete in pretty much any other field, but they're still the gold standard for guitar amplifiers. Despite huge advances in digital modelling, many guitarists still strongly prefer traditional tube amplifiers. Tube amplifiers are fragile, finicky, incredibly heavy and frequently too loud for domestic use, but they sound superb. The NuTube is by no means the first product to promise the sound of tubes in a lighter and more reliable package, nor will it be the last.
- anigbrowl 8y ago
  Yes. The secondary market for audio gear is very healthy, even for things that have stopped working and may only be useful for parts. It's so healthy that building modern clones of classic early innovations is a sustainable business model. Electronic music exists as it does because the advent of digital synthesis/recording technology in the 1980s led to mass abandonment of analog gear by rock and pop musicians, which was eagerly snapped up by broke hippies and hip-hop DJs. Commercial musicians jumped on the digital bandwagon for reliability, range, and repeatability (sounds stored as easily-recallable software presents instead of requiring tedious rewiring and knob-twiddling or having 10 keyboards on stage). Also, commercial musicians had mostly used synthesizers to substitute for acoustic instruments; it's cheaper to hire a keyboard player than a string or a brass section, and digital synthesis and sampling offered more realistic imitations than was possible with analog gear. Electronic musicians are more interested - no, obsessed = by the timbral characteristics and weirdness of the instruments themselves. I know people who have dedicated years of their lives to analysing and reproducing the characteristics of discontinued instruments like the TB-303 bassline as if it were a Stradivarius. Synth circuit engineers are venerated like stars at music equipment trade shows, and the social hierarchy of electronic musicians is ordered by their known propensity for experimenting or modifying their gear rather than commercial success. It's an interesting ecosystem. Anyway, rest assured that few if any of the products using this component will end up in a landfill.
vonseel 8y ago
Have any professional audio products been released using this technology yet? Guitar amps or similar. Is this purely used in audio or is there a display (video) usecase for this as well? The landing page seemed to imply the technology is coming from display tubes.
- droussel 8y ago
  Vox has released guitar amps with NuTube in them: https://www.voxamps.com/MV50 https://www.voxamps.com/MV50 Ibanez has also released a Tub Screamer that uses them: https://www.ibanez.com/na/products/detail/nts_01.html https://www.ibanez.com/na/products/detail/nts_01.html
  - jeremymcanally 8y ago
    And the Vox amps at least sound really great IMO. I had the "Clean" one for a while, which mimicks a Fender circuit. It sounded pretty darned close to a "real" tube amp. The only reason I got rid of it was I got a Fender Super Champ x2 with USB out for recording more easily.
- stonogo 8y ago
  Aside from the Vox MV50, I've never seen this in the wild. I hope someone proves me wrong, since the MV50 sounds great and I'd like to see what else is out there.
- tubetime 8y ago
  for audio, Korg has a gallery of examples: https://korgnutube.com/en/gallery/ https://korgnutube.com/en/gallery/ the tech uses the same manufacturing line as a traditional vacuum fluorescent display. VFDs are technically vacuum triodes where the plate has been painted with a phosphor. the device is probably not fast enough to be used as a video amplifier.
- tecleandor 8y ago
  Seems like you can also buy them (nut very cheap) and make a DIY project. https://www.rs-online.com/designspark/design-of-a-korg-nutube-amplifier-part-1-tube-basics https://www.rs-online.com/designspark/design-of-a-korg-nutub...
anon1253 8y ago
As an extreme tangent, but something that I was reminded of due to "tubes". I recently bought my first audio upgrade (Cambridge DAC 100, Little Dot MK III with Voshkod 6ZH1P-EV from the 70's on Beyerdynamic DT 1990 Pro headphones) and honestly, the first time I listened to it I was in tears. Coming from just plugging in some Sennheiser HD1 to my mobo audio out, the difference was staggering. There were sounds in tracks I was quite familiar with that I had never heard before. I bought a Schiit with a closed DT 1770 Pro for my office ... which wasn't nearly as good (and incidentally I think the filter caps might not handle the el cheapo DC-AC converter on the solar panels all that well which gives annoying (as in really audible) cracking and popping sounds even after tube rolling). Now for the downside: "audiophile" is a horrible niche to be in, there is so much cargo-culting and downright hostility that makes it a very "toxic" place to be in (not to mention stupidly expensive if you buy all the ahum "bs" ... a signal processing class would be a better investment...). But, I find the toxicity to be a little bit sad as well. Since it detracts people from a very real life improvement. Audio is one of the primary modalities of our sensory system, and even with mediocre hearing (like a male 30+ will likely have) you can, and do, hear an enjoyable difference for a modest investment. The difference between some second-grade Bluetooth thing and a nice "desktop" set /is/ real. My advice, get a nice open headphone (400-600$ range, I /really/ recommend something with a detachable cable since those fail first), something to replace your on board DAC for 150$, and an headphone amp (I like tubes, but for no other reason than that I like the way they look and "sound"). For something around 750-1000$ your life will be better and it'll last you a heck of a lot longer than any AirPod will (heirloom piece). That is, if you like listening to music, if not, disregard everything. Yes it's an investment, but this is HN, where I feel recommending 1k is not that big of a deal. Now for the more on topic part: apart from some high voltage DC applications like transceivers or transmitters (like microwaves!) tubes have largely been replaced by solid state. And with good reason, they last much longer, and are less conductive to all sort of ailments ... so apart from /super/ specialized applications they have no place. Apart from maybe providing that nice warm glow on your desk, when you're lonely, at night, and just want to listen to that "one song" while staring out of the window.
- ngcc_hk 8y ago
  Any recommendations for an easy to buy one in uk ?
tubetime 8y ago
for all the gory technical details, the datasheet is available here: http://korgnutube.com/pdf/Nutube_DatasheetV1E.pdf http://korgnutube.com/pdf/Nutube_DatasheetV1E.pdf interesting that they break the typical vacuum tube naming convention--the first number usually refers to the filament voltage. as a 6P1, i'd expect it to have a 6.3V filament, but it actually has a 0.7V filament!
byron_fast 8y ago
I want to believe. It may sound exactly like tubes. But if it doesn't look like a tube, and hurt when you touch it, it will probably be a market failure.
- byron_fast 8y ago
  See also: the Nuvistor. https://en.wikipedia.org/wiki/Nuvistor https://en.wikipedia.org/wiki/Nuvistor
- TimTheTinker 8y ago
  Also known as the Audiophile Economic Effect. :)
kazinator 8y ago
This is now in various products now, like a small amp Vox called the MV50 AC (NuTube in preamp section, Class-D power amp). Lots of YouTube demos. These Korg NuTubes were developed in conjunction with Noritake, the (only?) company that makes vacuum fluorescent displays.
bashinator 8y ago
Drop-in replacements for various common tubes used in audio applications (e.g. the 12AX7) would be an enormous market success. I wonder if there are any plans to make a higher wattage part that uses pentode design.
i_am_proteus 8y ago
Couple of notes from someone who has "designed" (adapted old schematics, really) and built tube amps for both hifi and electric guitar: - These things run at low voltages (5-80VDC), which is fantastic for a designer, because 'real' vacuum tubes need several hundred volts DC, which means a big power supply transformer/rectifier/filter network. - These things don't appear to be able to source a lot of current, which makes them good for preamp and tone circuits, not so much for power amp circuits. Classic tube guitar amps got a lot of their tone from the phase splitter, power amp tubes, and power amp transformers. Don't expect an all-nutube-amp. - Utility for guitar amps would be for "hybrid" amps with a tube preamp and tone circuit feeding a solid-state power amp. There's certainly room for experimentation by amp designers here, since most contemporary tube amps just copy old circuits (mostly Fender and Vox) and use the same tubes they used (12AX7 being the ubiquitous preamp tube). I doubt the NuTube sounds like a 12AX7 when dropped into the same circuit. - Utility for hifi is questionable. An all-tube design allows for a very linear, low-parts-count amplifier. These will need to be mated to a solid-state power amp, which nullifies the advantage of a tube amp and enters "vacuum tube as marketing gimmick" territory.
- jdietrich 8y ago
  >Classic tube guitar amps got a lot of their tone from the phase splitter, power amp tubes, and power amp transformers. 100% this. A tube gain stage in isolation isn't especially difficult to imitate using solid-state electronics or DSP, but sounds nothing like a tube amp. >Utility for guitar amps would be for "hybrid" amps with a tube preamp and tone circuit feeding a solid-state power amp. The Vox MV50 amps make a decent attempt at this, pairing a Nutube with a class D power stage. It's tiny, it's reasonably loud and it sounds pretty good. I suspect the lack of interest from other manufacturers is mainly due to cost; for the price of a single Nutube module, you could add a decent DSP chip and gain a whole bunch of extra functionality. An ornamental 12AX7 and an orange LED has better showroom appeal and costs significantly less. Purists will still want real tubes and real transformers, budget-oriented players will want an amp with all the DSP bells and whistles, leaving the Nutube caught in an uncomfortably narrow niche.
  - WalterBright 8y ago
icanhackit 8y ago
Interesting bit of trivia: The Noritake Group, the parent company behind Noritake Itron who make the VFD module, specialise in ceramic products ranging from circuit boards, dental materials, electronic paste to fine china. That's what I love about Japanese companies - the utter complexity of their product lines and exhaustive use of in-house talent. Though as Sony can attest, it can be their undoing as well.
- jmole 8y ago
  It's one reason that "lifetime employment" worked so well for them.
m0zg 8y ago
I wonder if these are any different to JFETs in blind auditions. People have been basically taking old Marshall circuitry and turning it into pedals using J201 JFET transistors. It's a bit of a bear to set up bias for, but the results are impressive enough that there's an entire cottage industry around this by now and some higher end manufacturers (e.g. Bogner Amplification) have jumped on the bandwagon. Needless to say, a JFET is at least an order of magnitude cheaper than this can ever be.
- analog31 8y ago
  The JFET is at a disadvantage from a marketing standpoint, because it faces the burden of proof, and is known to be cheaper. There's an automatic presumption that someone is using it to save money while making compromises to the audio quality. All it takes is one person to proclaim that it doesn't sound exactly like a tube. In contrast, a 12AX7 is indisputably a tube.
  - m0zg 8y ago
    But this is not 12ax7. And nutube is a cold cathode tube. There have been attempts to use low-power tubes called nuvistors before. Those are actually more of a tube than nutube, and they failed to get any traction. It's a notoriously fickle market, and tubes are still manufactured in China, Russia, and even in the US, so it's arguable if they need to be "replaced" by some newfangled thing.
    - analog31 8y ago
      Indeed, last I checked, a 12AX7 is like 5 bucks in quantity (and I'm no master at low cost sourcing), so it's barely even an economic argument. The guitar amp can't be made much smaller overall because it still needs a speaker.
- wishinghand 8y ago
  Which Bogner products are you referring to?
al2o3cr 8y ago
From the landing page: The real triode structure produces a warm, unique vacuum tube sound, delivering excellent linearity. "Tube sound" is nonlinearity. WTAF. See also the NuTube-powered headphone amp here, which measures 1+% THD at all practical output levels: http://www.nutube.us http://www.nutube.us Actually-linear headphone amps regularly achieve under 0.01% THD... Beyond that, compared to a "classic" preamp tube like the 12AX7 (very popular in guitar amps), the NuTube looks like it has: * simplified structure: the 12AX7 has indirectly-heated cathodes (the filament heats the electrode). This permits the two triodes to be used more-or-less independently. OTOH, the NuTube has a shared directly-heated cathode (the filament IS the electrode). Not a huge problem, but it means some circuits are trickier. Not likely to be cloning a K2-W, ferinstance. * lower anode voltage: the 12AX7 is specified down to 100V on the anode, but the datasheet considers 250V "typical". The NuTube has a maximum anode voltage of 80V, presumably due to the reduced size of the physical elements. This has the expected consequences for performance: lower gain (10 vs 100), lower transconductance (10uA/V vs 1250-1600uA/V) and higher plate resistance (300k vs 80k) * considerably different grid characteristics: the 12AX7 specifies an absolute maximum grid voltage of 0V, because taking the grid positive causes it to conduct electrons from the cathode and heat up. The NuTube specs don't mention a maximum, but the anode curves are shown for up to +4V on the grid. AFAIK grid conduction is sometimes considered part of "tube sound" when it happens in power output stages, but it's definitely not "linear". Other than the line from Vox (owned by Korg) it doesn't seem like the NuTube has gotten much uptake in the industry until recently - 2018 reviews for the Ibanez NTS mention it's the "first pedal with NuTube".
- i_am_proteus 8y ago
  To a degree, "vacuum tubes" are like "machine learning" and "blockchain" in that their presence in a product has a magical money-attracting quality that's often divorced from their active role in the product's operation. That said, comparing %THD between all-tube circuits and solid-state circuits for hifi isn't entirely apples-to-apples, especially since "single-ended-triode" type tube amps' distortion is predominantly in the second-order harmonic, which listeners often perceive as loudness or "roundness" or "warmth." I've listened to 2% THD tube amps that sounded pretty good to my ears, whereas a 2% THD solid state amp will generally sound like ass. Although, honestly, I haven't spent much time listening to ass, so there's a chance I might just be talking out of mine.
jdietrich 8y ago
If you think this is cool, wait until you see the Gamechanger Audio Plasma distortion pedal. It uses a xenon discharge lamp as the main tone-shaping element. https://www.gamechangeraudio.com/plasma/ https://www.gamechangeraudio.com/plasma/
- RileyJames 8y ago
  Just wow!! Lightning in pedal! And the sound is incredible. Check out this video at around 3 minutes and you can see the lightning triggering as he plays guitar: https://www.youtube.com/watch?v=_AZj5tc8EmA https://www.youtube.com/watch?v=_AZj5tc8EmA
  - jackhack 8y ago
    You'll love the tesla coil guitar amp, then: https://gizmodo.com/this-tesla-coil-guitar-amp-would-make-spinal-tap-weep-w-1795492685 https://gizmodo.com/this-tesla-coil-guitar-amp-would-make-sp...
ElijahLynn 8y ago
And... the site is down now. (504 Gateway Time-out)
ZoomZoomZoom 8y ago
First public reviews I saw note highly microphonic nature of these "tubes". This is a big disadvantage for applying them in guitar/bass amplifiers or any other live gear. Guitologist has a nice video review that could be interested to tinkerers and musicians: https://www.youtube.com/watch?v=raYGrKWSKRE https://www.youtube.com/watch?v=raYGrKWSKRE

168 points by ChuckMcM 8y ago

ChuckMcM 8y ago

These are pretty cool, it is a triode made out of vacuum fluorescent display tech.

mrandish 8y ago
Not much of a hardware guy... so what would this be useful for and better at?
- brian_herman__ 8y ago
  Music uses vacuum tubes due to the sounds that they produce.
- ChuckMcM 8y ago
  The way the thermal constant works in a tube is unique to its construction. As a result when you saturate an amplifier built with tubes rather than getting square wave clipping (which is full of odd harmonics) you get a modulated overtone. In Music systems this overtone has energy at musically compatible harmonics and so it still sounds good. In radios it can be easier to filter out the spurs (spurious overtones from non-linear operation) without swamping the modulation on the signal.
  - jackhack 8y ago
    translation: "an amplifier that sounds pleasant and warm, not harsh like a transistor."
    - sethhochberg 8y ago
      The thing to note is that (good) tube amplifiers can be designed to be very linear until they're driven too hard - the audiophile community often overlooks this detail when they're shopping for "warm" tube amps for general power amp duties. The big differences between tubes and other kinds of amplifiers appear when they're driven at, and especially past, their design limits. In an application like a guitar amplifier, some kind of effect/distortion pedal, etc the tube circuit is typically overdriven by design to get all of those warm harmonics. A tube that isn't being overdriven is every bit as capable of being a "wire with gain" as any kind of transistor or more modern circuit.
    - blattimwind 8y ago
      Good transistor amplifiers (i.e. 70s technology) are sufficiently good approximations of an ideal audio-band VCVS that they have no sound at all.
      - mark-r 8y ago
        I used to think that until I compared a couple. The most realistic sound I've ever heard was from a tube-powered system.
        ferongr 8y ago
        Post your statistically-significant double-blind testing logs.
        Applejinx 8y ago
        You do understand that your point of view is only one among many valid positions on the subject, some held by authoritative figures? (and I don't mean me, I'm thinking the likes of JJ) This isn't solely a defense of the position you challenged, more a call-out on your tactic here. You're not exactly representative. The talk of transistor amplifiers being perfect and having no sound at all is of course nonsense: typically this kind of claim looks at frequency response and outright ignores slew rate, crossover distortion, behavior as the amp exits its passband on either extreme, and so on. There CAN be transistor amplifiers, both simple and incredibly complex, that are so good that they've got effectively no sound at all. It's even possible that it's easier to get there with a transistor amplifier given enough money and resources. But that's not the claim.
        blattimwind 8y ago
        Liking tube sound or, more generally, the defects/characteristics of a particular amplifier (, headphones, speaker, room, ...) is perfectly fine with me. I get easily annoyed though when people start spewing pseudo-scientific BS justifying that deviations are objectively better than no deviations or that there are significant (or "obvious with good ears") differences between amplifiers where there simply are no such differences.
  - tubetime 8y ago
    eventually you do get a square wave (similar to a transistor) but with less overdrive, you get a "soft clip" waveform that is rich in second harmonics. these harmonics are an octave above the fundamental, and can also create a psychoacoustic effect where you hear another sound that is an octave below. bass players LOVE using tube amplifiers for this reason--it really fattens up the sound without making it sound crunchy.
- aidenn0 8y ago
  A tube amplifier sounds very different when clipping (i.e. try to amplify the signal past the maximum the amplifier can produce), and this is used to create distortion, most notably for electric guitars. There are DSP effects that can simulate this as well, of course.
tubetime 8y ago
it works with a regular VFD as well! see https://twitter.com/TubeTimeUS/status/1061797427991068672 https://twitter.com/TubeTimeUS/status/1061797427991068672 for a photo and the resulting waveform.

tlb 8y ago

Here's a project using actual VF display tubes as an amplifier: http://www.hpfriedrichs.com/radioroom/vfd/rr-vfd.htm http://www.hpfriedrichs.com/radioroom/vfd/rr-vfd.htm If you look at the wiggly plate current curves he measured, there should be plenty of harmonic distortion for tube audio enthusiasts. My 1970s HP oscilloscope contains several Nuvistors (https://en.wikipedia.org/wiki/Nuvistor https://en.wikipedia.org/wiki/Nuvistor), which are nearly as small. 17mm x 10mm dia.

ChuckMcM 8y ago
Wow, I think that first reference is going to put a crimp in Korg's patent application :-)
- bayindirh 8y ago
  I think it won't. Because it looks like there's even a magnet on the Korg's tube. They might be leveraged that same research, and listed it as a prior art or paid him as co-inventor.
  - ChuckMcM 8y ago
    The confusing bit for me, and realize I'm not a patent lawyer but have patented a few things, the referenced articles first publication was in 2008. I was told that in the US (but not in Europe) you have one year from public disclosure to file for a patent. (In Europe you give up your patent rights if you disclose first.) So to patent this you'd want to have filed in 2008. Here it is 10 years later. So why hasn't a patent issued? I've seen them take 3 - 5 years but 10 years seems like a stretch.
- tecleandor 8y ago
  BTW, the VFD used on the first link happens to be Noritake, that is, the same brand associated with work for the NuTube project, and the inventors of the VFDs, so this might not me new for them at all. And also, by the way, almost the only brand still manufacturing VFDs that are easy to find on the market (at least buying one by one). And also, they make pretty tableware :D

cordite 8y ago

Assuming 8 hours of use a day, this would last at least 10 years. Does audio equipment suffer less from the disposable electronics culture that we have with computers?

bayindirh 8y ago
I have an AKAI AM-2850 amplifer older than me. Its VU meters a bit lazy, but otherwise it's still shaking the house. I'm no way getting rid of it! P.S.: I generally dispose any of my devices when they let their magic smoke out. Computers stay at least five years and upcycled. Mine -> Family -> Extended family -> so on.
jdietrich 8y ago
Computers generally become obsolete at some point. Most audio equipment doesn't - newer equipment might be cheaper, more reliable or more convenient to use, but it probably doesn't sound any better. The cachet and mystique surrounding vintage equipment means that it often appreciates in value with age. Vacuum tubes are considered obsolete in pretty much any other field, but they're still the gold standard for guitar amplifiers. Despite huge advances in digital modelling, many guitarists still strongly prefer traditional tube amplifiers. Tube amplifiers are fragile, finicky, incredibly heavy and frequently too loud for domestic use, but they sound superb. The NuTube is by no means the first product to promise the sound of tubes in a lighter and more reliable package, nor will it be the last.
anigbrowl 8y ago
Yes. The secondary market for audio gear is very healthy, even for things that have stopped working and may only be useful for parts. It's so healthy that building modern clones of classic early innovations is a sustainable business model. Electronic music exists as it does because the advent of digital synthesis/recording technology in the 1980s led to mass abandonment of analog gear by rock and pop musicians, which was eagerly snapped up by broke hippies and hip-hop DJs. Commercial musicians jumped on the digital bandwagon for reliability, range, and repeatability (sounds stored as easily-recallable software presents instead of requiring tedious rewiring and knob-twiddling or having 10 keyboards on stage). Also, commercial musicians had mostly used synthesizers to substitute for acoustic instruments; it's cheaper to hire a keyboard player than a string or a brass section, and digital synthesis and sampling offered more realistic imitations than was possible with analog gear. Electronic musicians are more interested - no, obsessed = by the timbral characteristics and weirdness of the instruments themselves. I know people who have dedicated years of their lives to analysing and reproducing the characteristics of discontinued instruments like the TB-303 bassline as if it were a Stradivarius. Synth circuit engineers are venerated like stars at music equipment trade shows, and the social hierarchy of electronic musicians is ordered by their known propensity for experimenting or modifying their gear rather than commercial success. It's an interesting ecosystem. Anyway, rest assured that few if any of the products using this component will end up in a landfill.

vonseel 8y ago

Have any professional audio products been released using this technology yet? Guitar amps or similar. Is this purely used in audio or is there a display (video) usecase for this as well? The landing page seemed to imply the technology is coming from display tubes.

droussel 8y ago
Vox has released guitar amps with NuTube in them: https://www.voxamps.com/MV50 https://www.voxamps.com/MV50 Ibanez has also released a Tub Screamer that uses them: https://www.ibanez.com/na/products/detail/nts_01.html https://www.ibanez.com/na/products/detail/nts_01.html
- jeremymcanally 8y ago
  And the Vox amps at least sound really great IMO. I had the "Clean" one for a while, which mimicks a Fender circuit. It sounded pretty darned close to a "real" tube amp. The only reason I got rid of it was I got a Fender Super Champ x2 with USB out for recording more easily.
stonogo 8y ago
Aside from the Vox MV50, I've never seen this in the wild. I hope someone proves me wrong, since the MV50 sounds great and I'd like to see what else is out there.
tubetime 8y ago
for audio, Korg has a gallery of examples: https://korgnutube.com/en/gallery/ https://korgnutube.com/en/gallery/ the tech uses the same manufacturing line as a traditional vacuum fluorescent display. VFDs are technically vacuum triodes where the plate has been painted with a phosphor. the device is probably not fast enough to be used as a video amplifier.
tecleandor 8y ago
Seems like you can also buy them (nut very cheap) and make a DIY project. https://www.rs-online.com/designspark/design-of-a-korg-nutube-amplifier-part-1-tube-basics https://www.rs-online.com/designspark/design-of-a-korg-nutub...

anon1253 8y ago

As an extreme tangent, but something that I was reminded of due to "tubes". I recently bought my first audio upgrade (Cambridge DAC 100, Little Dot MK III with Voshkod 6ZH1P-EV from the 70's on Beyerdynamic DT 1990 Pro headphones) and honestly, the first time I listened to it I was in tears. Coming from just plugging in some Sennheiser HD1 to my mobo audio out, the difference was staggering. There were sounds in tracks I was quite familiar with that I had never heard before. I bought a Schiit with a closed DT 1770 Pro for my office ... which wasn't nearly as good (and incidentally I think the filter caps might not handle the el cheapo DC-AC converter on the solar panels all that well which gives annoying (as in really audible) cracking and popping sounds even after tube rolling). Now for the downside: "audiophile" is a horrible niche to be in, there is so much cargo-culting and downright hostility that makes it a very "toxic" place to be in (not to mention stupidly expensive if you buy all the ahum "bs" ... a signal processing class would be a better investment...). But, I find the toxicity to be a little bit sad as well. Since it detracts people from a very real life improvement. Audio is one of the primary modalities of our sensory system, and even with mediocre hearing (like a male 30+ will likely have) you can, and do, hear an enjoyable difference for a modest investment. The difference between some second-grade Bluetooth thing and a nice "desktop" set /is/ real. My advice, get a nice open headphone (400-600$ range, I /really/ recommend something with a detachable cable since those fail first), something to replace your on board DAC for 150$, and an headphone amp (I like tubes, but for no other reason than that I like the way they look and "sound"). For something around 750-1000$ your life will be better and it'll last you a heck of a lot longer than any AirPod will (heirloom piece). That is, if you like listening to music, if not, disregard everything. Yes it's an investment, but this is HN, where I feel recommending 1k is not that big of a deal. Now for the more on topic part: apart from some high voltage DC applications like transceivers or transmitters (like microwaves!) tubes have largely been replaced by solid state. And with good reason, they last much longer, and are less conductive to all sort of ailments ... so apart from /super/ specialized applications they have no place. Apart from maybe providing that nice warm glow on your desk, when you're lonely, at night, and just want to listen to that "one song" while staring out of the window.

ngcc_hk 8y ago
Any recommendations for an easy to buy one in uk ?

tubetime 8y ago

for all the gory technical details, the datasheet is available here: http://korgnutube.com/pdf/Nutube_DatasheetV1E.pdf http://korgnutube.com/pdf/Nutube_DatasheetV1E.pdf interesting that they break the typical vacuum tube naming convention--the first number usually refers to the filament voltage. as a 6P1, i'd expect it to have a 6.3V filament, but it actually has a 0.7V filament!

byron_fast 8y ago

I want to believe. It may sound exactly like tubes. But if it doesn't look like a tube, and hurt when you touch it, it will probably be a market failure.

byron_fast 8y ago
See also: the Nuvistor. https://en.wikipedia.org/wiki/Nuvistor https://en.wikipedia.org/wiki/Nuvistor
TimTheTinker 8y ago
Also known as the Audiophile Economic Effect. :)

kazinator 8y ago

This is now in various products now, like a small amp Vox called the MV50 AC (NuTube in preamp section, Class-D power amp). Lots of YouTube demos. These Korg NuTubes were developed in conjunction with Noritake, the (only?) company that makes vacuum fluorescent displays.

bashinator 8y ago

Drop-in replacements for various common tubes used in audio applications (e.g. the 12AX7) would be an enormous market success. I wonder if there are any plans to make a higher wattage part that uses pentode design.

i_am_proteus 8y ago

Couple of notes from someone who has "designed" (adapted old schematics, really) and built tube amps for both hifi and electric guitar: - These things run at low voltages (5-80VDC), which is fantastic for a designer, because 'real' vacuum tubes need several hundred volts DC, which means a big power supply transformer/rectifier/filter network. - These things don't appear to be able to source a lot of current, which makes them good for preamp and tone circuits, not so much for power amp circuits. Classic tube guitar amps got a lot of their tone from the phase splitter, power amp tubes, and power amp transformers. Don't expect an all-nutube-amp. - Utility for guitar amps would be for "hybrid" amps with a tube preamp and tone circuit feeding a solid-state power amp. There's certainly room for experimentation by amp designers here, since most contemporary tube amps just copy old circuits (mostly Fender and Vox) and use the same tubes they used (12AX7 being the ubiquitous preamp tube). I doubt the NuTube sounds like a 12AX7 when dropped into the same circuit. - Utility for hifi is questionable. An all-tube design allows for a very linear, low-parts-count amplifier. These will need to be mated to a solid-state power amp, which nullifies the advantage of a tube amp and enters "vacuum tube as marketing gimmick" territory.

jdietrich 8y ago
>Classic tube guitar amps got a lot of their tone from the phase splitter, power amp tubes, and power amp transformers. 100% this. A tube gain stage in isolation isn't especially difficult to imitate using solid-state electronics or DSP, but sounds nothing like a tube amp. >Utility for guitar amps would be for "hybrid" amps with a tube preamp and tone circuit feeding a solid-state power amp. The Vox MV50 amps make a decent attempt at this, pairing a Nutube with a class D power stage. It's tiny, it's reasonably loud and it sounds pretty good. I suspect the lack of interest from other manufacturers is mainly due to cost; for the price of a single Nutube module, you could add a decent DSP chip and gain a whole bunch of extra functionality. An ornamental 12AX7 and an orange LED has better showroom appeal and costs significantly less. Purists will still want real tubes and real transformers, budget-oriented players will want an amp with all the DSP bells and whistles, leaving the Nutube caught in an uncomfortably narrow niche.
- WalterBright 8y ago

icanhackit 8y ago

Interesting bit of trivia: The Noritake Group, the parent company behind Noritake Itron who make the VFD module, specialise in ceramic products ranging from circuit boards, dental materials, electronic paste to fine china. That's what I love about Japanese companies - the utter complexity of their product lines and exhaustive use of in-house talent. Though as Sony can attest, it can be their undoing as well.

jmole 8y ago
It's one reason that "lifetime employment" worked so well for them.

m0zg 8y ago

I wonder if these are any different to JFETs in blind auditions. People have been basically taking old Marshall circuitry and turning it into pedals using J201 JFET transistors. It's a bit of a bear to set up bias for, but the results are impressive enough that there's an entire cottage industry around this by now and some higher end manufacturers (e.g. Bogner Amplification) have jumped on the bandwagon. Needless to say, a JFET is at least an order of magnitude cheaper than this can ever be.

analog31 8y ago
The JFET is at a disadvantage from a marketing standpoint, because it faces the burden of proof, and is known to be cheaper. There's an automatic presumption that someone is using it to save money while making compromises to the audio quality. All it takes is one person to proclaim that it doesn't sound exactly like a tube. In contrast, a 12AX7 is indisputably a tube.
- m0zg 8y ago
  But this is not 12ax7. And nutube is a cold cathode tube. There have been attempts to use low-power tubes called nuvistors before. Those are actually more of a tube than nutube, and they failed to get any traction. It's a notoriously fickle market, and tubes are still manufactured in China, Russia, and even in the US, so it's arguable if they need to be "replaced" by some newfangled thing.
  - analog31 8y ago
    Indeed, last I checked, a 12AX7 is like 5 bucks in quantity (and I'm no master at low cost sourcing), so it's barely even an economic argument. The guitar amp can't be made much smaller overall because it still needs a speaker.
wishinghand 8y ago
Which Bogner products are you referring to?

al2o3cr 8y ago

From the landing page: The real triode structure produces a warm, unique vacuum tube sound, delivering excellent linearity. "Tube sound" is nonlinearity. WTAF. See also the NuTube-powered headphone amp here, which measures 1+% THD at all practical output levels: http://www.nutube.us http://www.nutube.us Actually-linear headphone amps regularly achieve under 0.01% THD... Beyond that, compared to a "classic" preamp tube like the 12AX7 (very popular in guitar amps), the NuTube looks like it has: * simplified structure: the 12AX7 has indirectly-heated cathodes (the filament heats the electrode). This permits the two triodes to be used more-or-less independently. OTOH, the NuTube has a shared directly-heated cathode (the filament IS the electrode). Not a huge problem, but it means some circuits are trickier. Not likely to be cloning a K2-W, ferinstance. * lower anode voltage: the 12AX7 is specified down to 100V on the anode, but the datasheet considers 250V "typical". The NuTube has a maximum anode voltage of 80V, presumably due to the reduced size of the physical elements. This has the expected consequences for performance: lower gain (10 vs 100), lower transconductance (10uA/V vs 1250-1600uA/V) and higher plate resistance (300k vs 80k) * considerably different grid characteristics: the 12AX7 specifies an absolute maximum grid voltage of 0V, because taking the grid positive causes it to conduct electrons from the cathode and heat up. The NuTube specs don't mention a maximum, but the anode curves are shown for up to +4V on the grid. AFAIK grid conduction is sometimes considered part of "tube sound" when it happens in power output stages, but it's definitely not "linear". Other than the line from Vox (owned by Korg) it doesn't seem like the NuTube has gotten much uptake in the industry until recently - 2018 reviews for the Ibanez NTS mention it's the "first pedal with NuTube".

i_am_proteus 8y ago
To a degree, "vacuum tubes" are like "machine learning" and "blockchain" in that their presence in a product has a magical money-attracting quality that's often divorced from their active role in the product's operation. That said, comparing %THD between all-tube circuits and solid-state circuits for hifi isn't entirely apples-to-apples, especially since "single-ended-triode" type tube amps' distortion is predominantly in the second-order harmonic, which listeners often perceive as loudness or "roundness" or "warmth." I've listened to 2% THD tube amps that sounded pretty good to my ears, whereas a 2% THD solid state amp will generally sound like ass. Although, honestly, I haven't spent much time listening to ass, so there's a chance I might just be talking out of mine.

jdietrich 8y ago

If you think this is cool, wait until you see the Gamechanger Audio Plasma distortion pedal. It uses a xenon discharge lamp as the main tone-shaping element. https://www.gamechangeraudio.com/plasma/ https://www.gamechangeraudio.com/plasma/

RileyJames 8y ago
Just wow!! Lightning in pedal! And the sound is incredible. Check out this video at around 3 minutes and you can see the lightning triggering as he plays guitar: https://www.youtube.com/watch?v=_AZj5tc8EmA https://www.youtube.com/watch?v=_AZj5tc8EmA
- jackhack 8y ago
  You'll love the tesla coil guitar amp, then: https://gizmodo.com/this-tesla-coil-guitar-amp-would-make-spinal-tap-weep-w-1795492685 https://gizmodo.com/this-tesla-coil-guitar-amp-would-make-sp...

ElijahLynn 8y ago

And... the site is down now. (504 Gateway Time-out)

ZoomZoomZoom 8y ago

First public reviews I saw note highly microphonic nature of these "tubes". This is a big disadvantage for applying them in guitar/bass amplifiers or any other live gear. Guitologist has a nice video review that could be interested to tinkerers and musicians: https://www.youtube.com/watch?v=raYGrKWSKRE https://www.youtube.com/watch?v=raYGrKWSKRE