Vacuum tubes

[RWebb]

We disagree, Curt. I approach this as a scientist, a biologist, and without double blind testing you have nothing. We also disagree on the linearity issue, and other aspects of this.

[Cajundaddy]

Well designed tube mic preamps, guitar amps, and audio amps sound fabulous. I am no golden ears audiophile but I have worked with this stuff for a very long time and can hear a difference that is distinctly pleasing to the ears. I will quantify this by saying... Idon'thaveacluewhy.

[nostatic]

Tubes. The lore is that when pushed to distortion, tubes favor even-numbered harmonics over odd-numbered harmonics while solid state don't. Even sounds better. Not sure but I know that two bits of music magic can be tube pushed into distortion and magnetic tape saturated.

[red-beard]

Originally Posted by cockerpunk

probably did. the main problem with tubes as a computer is 1. they are big and heavy 2. they generate lots of heat and most importantly 3. they break a lot. the first computers had 10s of thousands of tubes, and had run times measured in hours, because the likelihood that one tube, somewhere, in the building of tubes was broken, was pretty good.

in a world where we can put a transistor every 80 nm, its hard to justify tubes in almost any sense other then if you love how not mathematically perfect they are (audio)

First digital ones used actual mechanical relays. "Computer bug" phrase came from an actual bug caught in a relay.

As far as EMP, you can put a Faraday cage around things you want to protect.

[Rusty Heap]

Originally Posted by Curt914

Yeah and I know all about Bob Carver and the Stereophile test. I was his manufacterers rep for Carver Audio in the New York City area when that test took place.

Bottom line...linearity is always the goal (if your serious about audio serving music)!

I wasn't a sales rep for Bob back in his Carver and Phase Linear days, but a functional test engineer.

it was fun making the equipment scream during XYZ mode failure shutdown. Like a screwdriver across the speaker output terminals for a dead short with the amp at 80% total output.

I think I had 11000 watts of carver power in my living room at one time.

their Sunfire Subs are still earthshaking today.




of course my Dad baking the paint of his Heath Kit tube amp in the late 60's was always a fun reason to go to the tube-tester at the local drug store.


who else also had a Crystal Radio to listen to Dr Demento late at night while under the rocket ship or pony bed sheets?

[Nostril Cheese]

26 watts of vacuum tube goodness..

[Zeke]

I have been informed by a McIntosh factory service tech that in fact the tubes are now made in Russia and they are as good as ever.

So, it's the FAA that I was thinking about that uses tubes in their equipment?

[daepp]

Admiral Grace Hopper's log, where she documented the first computer "bug." It blew out some tubes iirc.

[jpk]

Back in the early 90's, my transportation engineering class got to go to the control tower at the airport. They showed us the computers used to track the planes and put the little ID numbers on the radar screens. They were these huge old Burroughs vacuum tube machines. I speak in plural because there were redundant systems with automatic failsafe switchover. They used field core memory - each bit of memory was a ferrite-ceramic ring with a coil of wire around it; depending on which way the current ran, the core would be magnetized with a positive or negative charge. There were racks and racks of panels about the size of a poster board with several hundred of these little rings on them.
I remember the guide telling us that these were originally designed for aircraft carriers and had proven reliability in less that ideal conditions, so the FAA was still using these systems, even though a programmable calculator could run circles around them for performance.

[RWebb]

where's Ian?

[cockerpunk]

any of you guys ever herd of or used anything from Resonant Electronic Design

[imcarthur]

Originally Posted by RWebb

where's Ian?

I'm hiding.

I have owned tubed things. I sell tubed things. They are what they are.

In the Pro world, tubed mic pres are typically called 'colored' while the expensive 'clean' mic pres are solid state . . . but both have their adherents & their place in the studio.

Ian

[beepbeep]

Very hi-power RF amps are still using tubes, and probably always will. There is just no way you can scale solid state into MW-range. Also, TWT (travelling wave tubes) are unmatched when it comes to amplifying signals at tens of GHz range.

That being said, tubes are quite sorry when it comes to amplifying anything else. They are noisy, non-linear, unefficient and short-lived and generally PITA to have in anything serious cept RF. That's why they are all gone.

They do distortion in graceful/fancy way though so people (me included) like them in stereo equipped. It's also somewhat steam-punkish as well, and...er...exclusive.

But a MOSFET power amp will wipe the floor with tube amp on just about any objective parameter: THD, frequency response, noise floor, efficiency etc etc. But I still like them and have built couple of them. Currently using home-built 2 x EL34 tube amp in my stereo.

P.S.
I'm secretly planning to do a monster OTL tube amp (no output transformer), which is about the holy grail of tube amp design.

[RWebb]

I dig MOSFETs.


BTW - check out this discount:

http://www.amazon.com/dp/B0082EBC3U

[imcarthur]

Actually in transistor amplifiers, the designs that I respect the most are all bipolar. Sometimes the designers are too . . .

Ian

[sammyg2]

I saw the blue man group in Vegas and Their tube music sounded AWESOME!

[widebody911]

Singing Ringing Tree (Panopticons) - Wikipedia, the free encyclopedia

[mreid]

TWTs, klystrons, and magnetrons are not vacuum tubes. They are high frequency oscillators used to produce radio waves and radar transmissions.

As for analog computers, if you know what a resolver, ball and disk integrator, or synchro are then you may have some analog computer experience. I worked on the Mk118 missile fire control computer when I was in the navy. It was an analog computer that also used vacuum tubes. nice!

[Gogar]

Originally Posted by Nostril Cheese

26 watts of vacuum tube goodness..

Sweet!!! How'd you get the extra 4 watts?

[nostatic]

gererator