Check out Vox's new guitar amp using Korgs NuTube Triode technology. The rep claims that the tubes are used in both the pre-amp and power amp and is capable of 150 Watts using only 2% of the power traditionally needed for vacuum tubes.
https://youtu.be/EB5QXWfPoaI
Now, I'm no EE. I am skeptical that the Korg NuTubes are the only amplifying devices. For the EE's and Amp designer's here, here is a video on YouTube of a DIY'er who has a spec sheet and explains the technology.
https://youtu.be/8MJ8XEzkfnY
What are you're thoughts on Korg's new Triode technology?
https://youtu.be/EB5QXWfPoaI
Now, I'm no EE. I am skeptical that the Korg NuTubes are the only amplifying devices. For the EE's and Amp designer's here, here is a video on YouTube of a DIY'er who has a spec sheet and explains the technology.
https://youtu.be/8MJ8XEzkfnY
What are you're thoughts on Korg's new Triode technology?
> The rep claims
Look at those guys' eyes. Do you think they are sober rational engineers? Or stoned music freeks?
> tubes are used in both the pre-amp and power amp
Watch my lips. ONLY tubes? Or tubes tarting-up modern devices? Uh, cool, man.
> is capable of 150 Watts using only 2% of the power traditionally needed for vacuum tubes.
I used to run 150W all-tube (Si rectifier) power amps. Say 450 Watts from the wall, hardly 550V if tube rectifiers were used.
Look at the screen-grab below. I see a Nu-Tube and a Class D power amp chip with 10W heatsink. So part-Watt for the Nu-Tube, 150W of output, 20W for power amp losses... say 180 Watts. 33% of an extravagant yet portable all-tube amp. (Non-portable tube power amps, the sky is the limit...)
Ah, the *idle* power could approach 2% of the all-tube stage amp. Tube amps are usually biased so they suck large power even at idle. The Class D amps naturally use "no" power at idle, maybe 11 Watts counting losses. But did you show up with a guitar and 150W amp to sit idle?
There is a "solar power" stage at a local county fair. I think in the past it ran on days of advance sun, batteries, and class AB car-sound amps. It could be 3dB louder or longer with the class D technology. But the Nu-Tube plays no part in that.
Look at those guys' eyes. Do you think they are sober rational engineers? Or stoned music freeks?
> tubes are used in both the pre-amp and power amp
Watch my lips. ONLY tubes? Or tubes tarting-up modern devices? Uh, cool, man.
> is capable of 150 Watts using only 2% of the power traditionally needed for vacuum tubes.
I used to run 150W all-tube (Si rectifier) power amps. Say 450 Watts from the wall, hardly 550V if tube rectifiers were used.
Look at the screen-grab below. I see a Nu-Tube and a Class D power amp chip with 10W heatsink. So part-Watt for the Nu-Tube, 150W of output, 20W for power amp losses... say 180 Watts. 33% of an extravagant yet portable all-tube amp. (Non-portable tube power amps, the sky is the limit...)
Ah, the *idle* power could approach 2% of the all-tube stage amp. Tube amps are usually biased so they suck large power even at idle. The Class D amps naturally use "no" power at idle, maybe 11 Watts counting losses. But did you show up with a guitar and 150W amp to sit idle?
There is a "solar power" stage at a local county fair. I think in the past it ran on days of advance sun, batteries, and class AB car-sound amps. It could be 3dB louder or longer with the class D technology. But the Nu-Tube plays no part in that.
Attachments
Assuming the NuTube is the low power triode based on VFD technology, then it is extremely unlikely that it is the main power device in an audio amp. You would need thousands of them! Being 'used in the output stage' is not the same as 'being used as the output device'.
Using it as a small-signal voltage amplifying device is possible, but even that is aimed more at marketing than sound engineering.
Using it as a small-signal voltage amplifying device is possible, but even that is aimed more at marketing than sound engineering.
I don't hear him claiming the tube is the output device. Uses 2% of the energy? The only energy the tube "uses" is the heater, so if their little Nutube doesn't have a heater, there you go. If I had to guess, it sounds like another let's stick a tube in a solid state amp and market it. Just they used their new tube thingie instead of a conventional tube.
Not the first amp to have a tube in the power amp feeding into a solid state power amp circuit. I've certainly seen a litle 12AU7 drive an "output transformer" which then passes the "tube sound" to a solid state final amp.
"Tubes are used" is not at all the same as "all tube."
Not the first amp to have a tube in the power amp feeding into a solid state power amp circuit. I've certainly seen a litle 12AU7 drive an "output transformer" which then passes the "tube sound" to a solid state final amp.
"Tubes are used" is not at all the same as "all tube."
Reminds me of the old saying, "you can tell a salesman is lying when you can see his lips moving". What you have there is a pure solid state amplifier with a single snake oil vacuum tube being called a "NuTube" , and its probably got a Class D power amp. This just stinks to high heaven of total bullshirt.
Sent from my phone with Tapatalk. Please excuse any typpos.
Sent from my phone with Tapatalk. Please excuse any typpos.
When you watch the video, it is clear the guy is totally honest and doesn't claim the NuTube provides 150W output. He goes on about how the tiny tube, using 2% of a 'regular tube power (it has a VERY small heater) provides the tube sound. He then demo's it with playing - gasp - actual music on a guitar.
Your slamming is totally unjustified.
By the way, Pete Millet has a thread here where he describes the details of the class D amp with a NuTube in the pre-stage. Totally above board.
Jan
"Check out Vox's new guitar amp using Korgs NuTube Triode technology. The rep claims that the tubes are used in both the pre-amp and power amp and is capable of 150 Watts using only 2% of the power traditionally needed for vacuum tubes."
...except he never claims that!
Yes, you are right, you are no EE.
...except he never claims that!
Yes, you are right, you are no EE.
Jan, my post was addressed to Xaborus's first post, not you, I was just too slow at typing.
Otherwise I agree with your post. I have not read it before I posted.
Otherwise I agree with your post. I have not read it before I posted.
That is how marketing works, you don't need to lie, the customers misinterpret things on their own. The marketer is not innocent in that relationship. They know how customers react.
Well, I actually downloaded and read the datasheet, can read and understand the curves and can design a gain stage on the back of an envelope in about 2 minutes.
YES: it IS a Tube.
In fact it´s a true triode and is capable of doing anything a triode does, exactly the same way.
And it does that at way lower power than, say, a 12AX7.
Meaning: it will clip like the triode it is
It can provide gain (although not much, even a humble 12AU7 beats it).
VCC=12V
Anode load=330kΩ
Gain 14dB (very poor 5X gain)
Maximum output 10dBV (3V RMS)
It will give you tons of harmonics, specially lots of even ones, it´s VERY non linear so if you want to add tube flavour, it does so brilliantly-
Here are the current/voltage/bias curves which are true triode like (not surprising considering it IS a triode) and it can be used similar to a 12AX7 if fed high voltage (80V), including negative grid bias and relatively high input impedance;
BUT: if you have high voltage available, even humble 80V, a conventional triode is both better and cheaper , 12AU7 is happy at 80V , so nobody would use U$50 a pop Nutubes, so their market will be inside multieffect units and pedals,its filament needs only 17mA , can even be fed from a 9V alkaline battery if needed and provide 30/40 hours life, so there is where it will shine (pun intended 😉 )
As a tube sound and harmonics generator it is brilliant, and even more at low plate voltage, since it works straight in the most non linear part of the curve.
Notice it provides 10% distortion, most of it even, at 0dbV output (1V RMS) , perfect to drive any SS power amp, Class AB or D which needs only to amplify such waveform to speaker driving levels.
Now to the problems:
1) above mentioned low gain, although you can drive it with a clean Op Amp and let it provide all the nonlinearity and harmonics-
2) at such low voltages, it needs positive bias simply to pass some current.
Which means grid is passing current and now is low impedance.
Not news, both Blue Tube and Mini Boogee pedals (among others) do exactly the same ... and using 12AX7
3) plate current is very low, needs a large plate resistor just to drop some useful voltage, so "it can drive no real world load"
To address points 2 and 3, it is recommended to add a buffer before and a buffer after each NuTube stage
So in a nutshell: it is not a gimmick, even less a glorified pilot light, it can be used to build gain stages which can add lots of flavout to conventional SS stages.
And besides low gain per stage, you can stack as many as you need to build full tube preamps if that rocks your boat.
Almost forgot: they are quite microphonic, Korg suggests mounting them on a foam floating sub PCB.
Would I use them to dessign a commercial product?
At U$ 50 each? NO WAY
Specially considering Noritake probably charges a couple bucks each to Korg, after all they ARE just one specialized fluorescent display, same as those found by Millions in microwave ovens, VCR/CD players, clock radios and TVs.
In fact will check what surplus Fluo displays can I get locally for peanuts, trace and build my own 😉
Will certainly very close.
And no, I don´t consider this a Korg gimmick, rather a BRILLIANT idea, and it can do what it claims.
Not that it claims too much in any case.
As of the demo shown in NAAMM, that head sounds killer, NuTube or not, and the demo player knows his sheet ... he has also demoed lots of other stuff.
YES: it IS a Tube.
In fact it´s a true triode and is capable of doing anything a triode does, exactly the same way.
And it does that at way lower power than, say, a 12AX7.
Meaning: it will clip like the triode it is
It can provide gain (although not much, even a humble 12AU7 beats it).
VCC=12V
Anode load=330kΩ
Gain 14dB (very poor 5X gain)
Maximum output 10dBV (3V RMS)
It will give you tons of harmonics, specially lots of even ones, it´s VERY non linear so if you want to add tube flavour, it does so brilliantly-
Here are the current/voltage/bias curves which are true triode like (not surprising considering it IS a triode) and it can be used similar to a 12AX7 if fed high voltage (80V), including negative grid bias and relatively high input impedance;
BUT: if you have high voltage available, even humble 80V, a conventional triode is both better and cheaper , 12AU7 is happy at 80V , so nobody would use U$50 a pop Nutubes, so their market will be inside multieffect units and pedals,its filament needs only 17mA , can even be fed from a 9V alkaline battery if needed and provide 30/40 hours life, so there is where it will shine (pun intended 😉 )
As a tube sound and harmonics generator it is brilliant, and even more at low plate voltage, since it works straight in the most non linear part of the curve.
Notice it provides 10% distortion, most of it even, at 0dbV output (1V RMS) , perfect to drive any SS power amp, Class AB or D which needs only to amplify such waveform to speaker driving levels.
Now to the problems:
1) above mentioned low gain, although you can drive it with a clean Op Amp and let it provide all the nonlinearity and harmonics-
2) at such low voltages, it needs positive bias simply to pass some current.
Which means grid is passing current and now is low impedance.
Not news, both Blue Tube and Mini Boogee pedals (among others) do exactly the same ... and using 12AX7
3) plate current is very low, needs a large plate resistor just to drop some useful voltage, so "it can drive no real world load"
To address points 2 and 3, it is recommended to add a buffer before and a buffer after each NuTube stage
So in a nutshell: it is not a gimmick, even less a glorified pilot light, it can be used to build gain stages which can add lots of flavout to conventional SS stages.
And besides low gain per stage, you can stack as many as you need to build full tube preamps if that rocks your boat.
Almost forgot: they are quite microphonic, Korg suggests mounting them on a foam floating sub PCB.
Would I use them to dessign a commercial product?
At U$ 50 each? NO WAY
Specially considering Noritake probably charges a couple bucks each to Korg, after all they ARE just one specialized fluorescent display, same as those found by Millions in microwave ovens, VCR/CD players, clock radios and TVs.
In fact will check what surplus Fluo displays can I get locally for peanuts, trace and build my own 😉
Will certainly very close.
And no, I don´t consider this a Korg gimmick, rather a BRILLIANT idea, and it can do what it claims.
Not that it claims too much in any case.
As of the demo shown in NAAMM, that head sounds killer, NuTube or not, and the demo player knows his sheet ... he has also demoed lots of other stuff.
It is clearly targeted to give analog (non-DSP) some 'analog tube sound' without the cost of high voltage and lots of heat. Bands will love it.
See also http://www.diyaudio.com/forums/vendors-bazaar/302238-korg-nutube-now-available-online-5.html
Jan
See also http://www.diyaudio.com/forums/vendors-bazaar/302238-korg-nutube-now-available-online-5.html
Jan
> Noritake probably charges a couple bucks each to Korg, after all they ARE just one specialized fluorescent display, same as those found by Millions in microwave ovens, VCR/CD players, clock radios and TVs.
What is "BRILLIANT" is that VFDs are NOT common anymore. After some decades making VFDs flat-out, suddenty GUI on LED/TFT displays are hip, and Noritake was turning out the lights in the VFD factory.
They still will. But KORG got them to leave one small VFD line running, possibly with the ton of filament-wire still in stock, with slightly modified electrodes (always to the customer's blueprint). Production cost can't be $5 each. How Noritakie and KORG split the $45 excess is between them. But VFD demand is going to zero, KORG pedals are being hit by $69 clones, so this exclusive product is a bright spot for both.
What is "BRILLIANT" is that VFDs are NOT common anymore. After some decades making VFDs flat-out, suddenty GUI on LED/TFT displays are hip, and Noritake was turning out the lights in the VFD factory.
They still will. But KORG got them to leave one small VFD line running, possibly with the ton of filament-wire still in stock, with slightly modified electrodes (always to the customer's blueprint). Production cost can't be $5 each. How Noritakie and KORG split the $45 excess is between them. But VFD demand is going to zero, KORG pedals are being hit by $69 clones, so this exclusive product is a bright spot for both.
I have no doubt that JM will be able to get some very cool sounds out of a VFD display. PRR you made some really good comments. Question is whether any company is going to be committed to long term production on this technology. I put that in the sense that we still have very good standard tubes that seem to be very stable in supply.
Didn't they already do that like 60 years ago? NOS 6111 dual triode subminiature vacuum tubes | eBay
Those sub-miniature tubes aren't really low voltage tubes and still require a 6.3V heater supply. So not quite as convenient as NuTubes for FX pedals. But they can really sound fantastic, as anyone who's heard the ZVex Nanohead will testify.
I've also considered battery tubes for FX pedals,, and they can run off quite low B+ voltages, but unfortunately need a 1.5V DC filament supply.
Now I'm wondering if it might make sense to plunder a bunch of those electroluminscent display tubes out of an old Casio calculator I have lying around. 🙂
Sent from my phone with Tapatalk. Please excuse any typpos.
We really are fixated on the wrong side of the iron curtain.
The things I want to play with in pedals (but have been too busy to get to) are the russian pencil or rod valves. 50mA at 1V on the heater and 60V on the anode. Almost all pentodes but very linear in triode mode.
I'd love to do a marshall JMC800 micro clone with these tubes - less than 100mW of output power into a dummy or small speaker (per Fred Nachbaur's Dogzilla's small amp)
See Joe Sousa's article on RadioMuseum
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