Future of Tubes is TODAY

[Chuck H]

Maybe they don't realize how much of the demand is because they are socketed and wear out. You want to deny guys (especially in hi-fi) who spend their days nitpicking over tube differences and constantly trying out different tubes? How do you brag about the price you paid?
I think for their own Korg products, cool idea. But I don't think anyone is interested in some new version of a tube that is not backwards compatible.
But maybe they are only thinking in terms of their own products.

You may be correct about this being part of the reason tube circuits continue to appeal. For my own sensibilities I don't get that aspect. Before I even started learning about circuits I was talking to one of the owners of GK and told him "If anyone comes up with a SS amp that sounds as good as a tube amp I'll buy it and never look back." I feel the same way about these new devices. If they sound good, they ARE good. I build very few amps. And my customers have very clear ideas about what they want. I'll still build whatever they want. But I'm no purist and I have no loyalties to any vintage ideology. I'd welcome the opportunity to design around a device that sounds as good as the tubes we use now but offers the advantages reported for the Nutube. I think you would too but I'm enjoying your feigned defiance. Resistance is futile. I read on one forum that discussed the Nutube where a member said he was considering selling his SVT reissue while it still had value!?! It could happen. Not every tube amp guy is a crank. Many just want a good sounding amp. Whatever it's made of.

[Diablo]

I hope this Nutube works out and you can build a reliable amp that sounds as good as the old style tube amp. I still think there will be a market for the old style tube - for all those guys who are putting gold fuses in their stereos and other means to purify their AC voltage.

[Silvertone Jockey]

Maybe they don't realize how much of the demand is because they are socketed and wear out. You want to deny guys (especially in hi-fi) who spend their days nitpicking over tube differences and constantly trying out different tubes? How do you brag about the price you paid?
I think for their own Korg products, cool idea. But I don't think anyone is interested in some new version of a tube that is not backwards compatible.
But maybe they are only thinking in terms of their own products.

Finally a discussion I can weigh in on with a somewhat small sense of authority (Who gives a F I'll take it! ) If this new tube idea takes off backwards compatibility is a non issue. Trust me you will be able to buy a version of this design tailored to be the equivalent of your favorite flavor of !2xx7 and more.

I am full in on this one and I sell vintage tubes to augment my income which is a contradiction in of itself. Bring em on and hope they are awesome

[tedmich]

while patent is reported as "applied for" I haven't been able to find it in USPO applications

lots of tube replacement PAT. applications from this guy: http://www.robertsaudiotech.com/designs/retrovalve.php

Good discussion over at DIYStomp! Philips made these in 1959 apparently

http://www.diystompboxes.com/smfforu...6246;topicseen

[Jazz P Bass]

This gentleman went ahead and actually wired up a VFD display & it did amplify the signal.(in a very limited way.)

The H.P. Friedrichs (AC7ZL) Homepage

[J M Fahey]

Thanks for searching and posting that very interesting page.

Now I think that the Korg device must work very well, since it's designed specifically to amplify.

Look what this experimenter found, using a car/clock display wired as an audio triode

Above is an image of my "CDROM" radio, a crystal radio set based upon the container in which CDROMs are sold. I connected this radio to the VFD as represented in the simplified schematic above. Music came blasting through the headphones. Despite the fact that my antenna consisted of no more than 15 feet of wire thumb-tacked to the ceiling, the amplifier worked so well that the volume in the headphones was unpleasantly loud.

a) The amplifier works when the audio signal from the crystal set is positive with respect to ground. It is almost completely non-functional when the detector diode is reversed and the audio signal becomes negative with respect to ground.

b) The VFD can function as both detector and amplifier. I verified this by bypassing the diode in the CDROM radio. Volume was reduced, but the amplifier still worked just fine.

c) The apparent gain of the amplifier is dependent upon the voltage applied to the "super" anode of the display. I have a variable high-voltage power supply. The amplifier provided useful amplification with an anode voltage of about 60 volts. At 90 volts, the amplifier worked much better. At 150 volts, the audio in headphones was so loud that music and speech could be heard with the headphones simply lying on the table.

d) Anode current never exceeded 6 milliamps. While this limits the VFD’s usefulness as a general purpose amplifier, it is more than up to the task of driving high impedance headphones.

On this basis of this data, it appears that the particular VFD I was playing with, depending upon operating point, offers amplification on the order of 15 to 20 times—a respectable amount of gain.

Eeeeenckreeddibullll !!!

[Chuck H]

Great detailed info in the link with some useful tech on the matter. Mostly speculation about the actual device. Still, likely limitations and what should be possible are explored. If these become available for the public at a decent price I'd be interested. Some of my concerns...

Directly heated cathode may require complicating the filament circuits to adapt these devices for low noise operation.

Low gain would mean multiple devices for the same amplification, especially if clipping these devices is the goal. Possibly resulting in a higher noise floor.

A power supply for the lower operating voltages and higher current standing idle will pretty much null any effect of the bouncing power effect dynamic we're use to with guitar amps. Especially if amps that use these DON'T use power tubes. And if those amps DO use power tubes that does away with any advantage of not needing a HV supply. So, what's to gain? (no pun intended).

The durability of the vintage PTP and eyelet/turret board designs is sacrificed because these are SMD's. Any amps designed with these will follow that construction method.

Because these would need peripheral SS amplifiers to achieve guitar amp tube type circuit performance there would be a lack of dynamic circuit to circuit impedance unless much more complicated design considerations are met.

In other words. I don't think these will sound at all like the tubes we use now without unreasonably complicated designs and the default amp construction method pretty much negates any improved reliability advantage.

All of the above is me speaking out of my depth of technical expertise, but it all seems like reasonable observations.

I predict that in actual use any amp KORG makes with these devices will have some of them in the circuit as token "vacuum triodes" that won't be doing anything like clipping or otherwise offer the distortions we enjoy about current tube designs. It will probably be little more than any other SS preamp but KORG will make a lot of noise about vacuum tube performance in the literature and hype.

[tubeswell]

Good discussion over at DIYStomp! Philips made these in 1959 apparently

Korg 'Nutube' - next generation vacuum tubes

Good old PRR with the low-down.

[Silvertone Jockey]

I predict that in actual use any amp KORG makes with these devices will have some of them in the circuit as token "vacuum triodes" that won't be doing anything like clipping or otherwise offer the distortions we enjoy about current tube designs. It will probably be little more than any other SS preamp but KORG will make a lot of noise about vacuum tube performance in the literature and hype.

Then there is the fact that these say Korg on them in the first place. Every piece of Korg gear I have tried is junk..........just saying

[J M Fahey]

Then there is the fact that these say Korg on them in the first place. Every piece of Korg gear I have tried is junk..........just saying

Hi SGM !!! Long time no see !!!!
Didn't recognize you under your new avatar

FWIW Marshall was exclusively distributed in USA by Korg, so legally and commercially Marshall was "a Korg product" from 1985 to 2010 .

And VOX has been owned and made by Korg since 1992 , what also makes it a Korg product.
So VOX is also a crappy product?

Nice to know, I wouldn't have imagined it if you didn't open my eyes.

Korg and Marshall Go their Separate Ways | MITA International

As of Digital stuff, keyboards and related processors, I guess they are second to none in the World, just the list of their products is mind numbing:
List of Korg products - Wikipedia, the free encyclopedia

[Chuck H]

Easy now. Calling someone SGM is just mean. I think a bigger offence than a single malign of a parent company is in order for that

I'm not a big KORG fan, but that's partly because they're HUGE. Yessir, they make some awful, cheap and clearly disposable products that defame the VOX and Marshall logo's they brandish. But they are also the reason you can buy an AC30 today! Overall though I think every product they've taken control of has been cheapened and generified without a corresponding reduction in price. A large company isn't something you decide to be. You need to do it. That gets done with dollars and decisions. There's no room for sentimentality, pride, etc. It's all about giving 'em what they want at a profit. And it turns out we want big brand names on cheap $h!tty amps sometimes. The other part of becoming big includes not giving anything more than you have to. And KORG doesn't. My experience with them has been limited. I guess their customer service is as good as one should expect considering that their product support has long been reported as (and personally experienced as) awful. So, not a big KORG fan. This is my clear statement why. So I understand not liking the company. But you CAN buy a decent reissue plexi or an AC30 because of them.

And, FWIW, it's entirely possible that every piece of KORG gear Silvertone Jockey has tried was indeed junk. They do make a lot of that sort of gear. Even if that's not all they make.

[octal]

Those curves for the VFD are pretty wavy. Might sound better than a "real" tube for a guitar amp application.

[Justin Thomas]

Every OLD Korg piece of gear I owned lasted forever. I'm really a cheap SOB, so when my Korg analog tuner from 1994 took one too many case-shattering leaps to the floor 20 years later, I cried. Actually, it still worked but the needle had been bent so many times it would get hung up. The new $10 digital replacement (that I paid $5 for) can't touch it. But, a digital Boss will replace it IF I can only pay $20 for it...

We should all probably accept the fact that those bazillions of cheap amps/keyboards are what gives them the capital to keep Vox & Marshall alive in this hemisphere... :/

Juan, I didn't see any pictures of ice-climbing hammers being touted as bias tools, so this is clearly not SGM. Now, I know Corg & Krate both start with a "K" sound; maybe your eyes tricked you?

Justin

[Justin Thomas]

Those curves for the VFD are pretty wavy. Might sound better than a "real" tube for a guitar amp application.

When YOU build the amp, I will try it, because you're thinking of the flaws and compromises being used to make something unique, not pass off This for That. Kudos!

Justin

[Chuck H]

I didn't see any pictures of ice-climbing hammers being touted as bias tools, so this is clearly not SGM.

I really should get one of those rubber, water proof covers for my keyboard. That or stop drinking anything at my computer desk while reading the forum