So what's the deal with Nuvistors then?

[frequencycentral]

There are very few threads about them if you do a search. Being a submini tube guy they fascinate me. Anybody used them? Any good resources? They seem a little pricey..........worth experimenting with?

http://en.wikipedia.org/wiki/Nuvistor

Here's a 7586 medium mu triode:

http://frank.pocnet.net/sheets/049/7/7586.pdf

http://frank.pocnet.net/sheets/030/7/7586.pdf

[Taylor]

I was interested in this, too, but like you, I couldn't find much info. I did find that some hifi stereo gear uses nuvistors, but apparently the miniaturization makes (made?) for inconsistent quality.

I think you should give them a shot. Seems the logical step after subminis, and if anyone here is up for it, seems like you'd be the one, eh?

[Ripthorn]

I have looked into them some, but they are more expensive than subminis and harder to find.  From what I know, they are simply small tubes in little cans that were originally made for things like missile guidance.  After playing with the submini's, I will stick with them since they are cheaper and not much bigger .

[Ice-9]

You probs found this link already but its a good read
http://www.thevalvepage.com/valvetek/Nuvistor/nuvistor.htm

[frequencycentral]

I think you should give them a shot. Seems the logical step after subminis, and if anyone here is up for it, seems like you'd be the one, eh?

I can't resist them, I have to get some!

I have looked into them some, but they are more expensive than subminis and harder to find.  From what I know, they are simply small tubes in little cans that were originally made for things like missile guidance.  After playing with the submini's, I will stick with them since they are cheaper and not much bigger .

But what about the mojo? And bragging rights?

[Paul Marossy]

The original Techtronix 453 oscilloscope used Nuvistors. Most of those are out of commission now because you can't get replacements for those anymore. The later ones used transistors instead.

[Ripthorn]

But what about the mojo? And bragging rights?

You can spend the extra cash on bragging rights and mojo, as a grad student, I will just focus on the budget items.

[Baktown]

As luck would have it, I just found an old abandoned farmhouse in the deep woods of southern Oklahoma that has a bunch of old TV sets from the late 50's.  If I can find some of these, I would be more than happy to share them.  I really like this part of the world, there are all kinds of old TV's and radios ripe for the picking...

Rick J - Newly christened redneck treasure hunter

[Jered]

  I hear that. I was recently in AK and found houses/farms that have 24/7 yard/rummage sales. If I would have been there for more than two days I could have torn stuff up! Lots of old radios and TV's.
  As for nuvistors. Would like to give them a try but, the price.

[Mick Bailey]

As luck would have it, I just found an old abandoned farmhouse in the deep woods of southern Oklahoma that has a bunch of old TV sets from the late 50's.  If I can find some of these, I would be more than happy to share them.  I really like this part of the world, there are all kinds of old TV's and radios ripe for the picking...

Rick J - Newly christened redneck treasure hunter

Too spooky for me. Do the TVs still pick up 50's TV shows? Careful you don't get hacked to death by zombie rednecks......

[Baktown]

Too spooky for me. Do the TVs still pick up 50's TV shows? Careful you don't get hacked to death by zombie rednecks......

Around here the old Louisiana Hayride shows still get shown late at night on local stations.

A "Zombie Redneck" is by definition a tweaker wearing a wife beater, overalls, a mullet, and possessing no more than 3 functioning teeth (4 teeth would qualify him to be mayor).  Of course, a tattoo of a rebel flag always earns extra points...

Rick J

[idiot savant]

I have a dozen or so of 6cm4's. they sound real nice, will take HV, but they are prone to microphonics. sockets for em are ungodly rare and expensive too.

[Jered]

Too spooky for me. Do the TVs still pick up 50's TV shows? Careful you don't get hacked to death by zombie rednecks......

Around here the old Louisiana Hayride shows still get shown late at night on local stations.

A "Zombie Redneck" is by definition a tweaker wearing a wife beater, overalls, a mullet, and possessing no more than 3 functioning teeth (4 teeth would qualify him to be mayor).  Of course, a tattoo of a rebel flag always earns extra points...

Rick J

And man-o-man do they love them some camo! Camo houses, vehicles, and most clothing. A whole different mindset. When my AK kin visit CA they think we're all half crazy, and "why are all in such a hurry"

[frequencycentral]

OK! I'm learning a lot about the deep south that John Steinbeck and Erskine Caldwell never mentioned!   

But less about nuvistors! 

Hehehe - amusing though.......!

[aziltz]

old thread I know, but I just found about 10 nuvistors, and I'm wondering if anyone found time to put together a circuit or two for them?

[amptramp]

Idiot savant is right, the sockets are more likely to be a problem than the tubes themselves.  I also have a plentiful source of compactron tubes but only one socket and most of the ones available are for printed circuit use only, but they are another great tube family that is stymied by lack of sockets.

Most nuvistors were triodes used as RF amplifiers for TV tuners.  As such, they are good for low-voltage signals.  The original one was the 6CW4, a triode with a mu of 68, transconductance of 12,500 umhos and a plate resistance of 5400 ohms.  The filament takes 6.3 volts at 135 mA, so it is relatively easy on heater current.  It was typically run at 70 volts on the plate @ 7.2 mA.  In other words, a pretty good tube for a preamp or effects unit.

[PRR]

> Most nuvistors were triodes used as RF amplifiers for TV tuners.

Right. They may have originated in mil-spec projects, but *better* TV sets often had ONE (maybe two) Nuvistor(s) in the very first stage. (They may be seen as descendants of the old-old "acorn" tubes.)

Their main advantage lays above 100MHz. Since this is 10,000 times (12 octaves) above the highest overtone we ever want to hear, they have no electronic advantage for "us".

And they don't glow. That, for me, is a "why bother?" fault.

[idiot savant]

> Most nuvistors were triodes used as RF amplifiers for TV tuners.

Right. They may have originated in mil-spec projects, but *better* TV sets often had ONE (maybe two) Nuvistor(s) in the very first stage. (They may be seen as descendants of the old-old "acorn" tubes.)

Their main advantage lays above 100MHz. Since this is 10,000 times (12 octaves) above the highest overtone we ever want to hear, they have no electronic advantage for "us".

And they don't glow. That, for me, is a "why bother?" fault.

I don't completely agree with that, though for the most part you are correct.

There are many good examples of nuvistor audio circuits, especially in high-end mic preamps, see the Neumann U-47 for example. They may have been selected for size, power requirement issues rather than their proficiency at AF, who knows.

For those that have been here long enough, you might remember Al Hermida's nuvistor pedal.

For all intents and purposes, they aren't suitable just due to lack of them and their support parts(sockets)... I think I paid $5 more for my stash of Cinch sockets, than I did for the stash of tubes! The Tektronix surplus store here in PDX has 'em from time to time

-Morgan

[aziltz]

can they be soldered in like subminis?  I have a whole slew of them I'm hopping to use.

[Taylor]

Wow, these things are smaller than I thought:

http://upload.wikimedia.org/wikipedia/en/b/ba/Nuvistor_530.jpg

aziltz, have you seen this?

http://www.tnt-audio.com/clinica/preamble_n.html