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Building DIY vacuum tubes

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I've been thinking about the best low power triode to build an audio pre-ampilfier with. After looking at the choices available on eBay I've become enamored with the WE 101D. I like the planar electrode configuration and it looks like an easy tube to build. The things that I'll redesign from the original will be the filament and the glass arbor mounting arrangement. The extra pins on the button pinch will make it much easier to mount and align the innards and make it more ridged and reliable.

I like directly heated cathodes so I'm going with thoriated tungsten as the emitter. The bulb will be of the straight wall variety instead of the tennis ball shape. From what I've read on the audio forums the WE 101D is still a highly regarded tube. We'll see how it all works out.
 

tcmtech

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Do you have an ultra-high vacuum pump to suck your creation empty when you are done plus all the other highly specialized tooling and equipment required to manufacture a viable vacuum tube of any kind?

http://tubecrafter.com/tubecrafter_012.htm

If not then you are waisting your time.
 
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Thank you for the reply. Yes, I've collected enough tools to accomplish the task. I appreciate the warning, though. My wife says that I waste my time drinking too much beer. She also claims that my confidence far exceeds my capabilities. It seems that I'm always torn between the things I enjoy doing most. This makes it difficult to march a straight course.
 

KeepItSimpleStupid

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George. Cool. Although I have a lot of the skills. I don't have an interest nor the equipment. I can operate, troubleshoot and put together such equipment and I can do the vacuum seals. I can do minimal glass blowing with quartz and Pyrex. Quartz in nicer to work with. I used a Hydrogen Oxygen torch for purity purposes.
 

atferrari

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I've been thinking about the best low power triode to build an audio pre-ampilfier with. After looking at the choices available on eBay I've become enamored with the WE 101D. I like the planar electrode configuration and it looks like an easy tube to build. The things that I'll redesign from the original will be the filament and the glass arbor mounting arrangementpaillard.claude.free.fr. The extra pins on the button pinch will make it much easier to mount and align the innards and make it more ridged and reliable.

I like directly heated cathodes so I'm going with thoriated tungsten as the emitter. The bulb will be of the straight wall variety instead of the tennis ball shape. From what I've read on the audio forums the WE 101D is still a highly regarded tube. We'll see how it all works out.
Go here paillard.claude.free.fr

Scroll down to the very bottom. Click on "Fabrication d'une lamp triode". Enjoy.
 

tcmtech

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audioguru

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Doesn't a single vacuum tube produce fairly high even-harmonics distortion something like a single transistor that has no negative feedback? Isn't a double transistor preamp with lots of negative feedback much better with very low distortion?
 
From what I've read and listened to I'd have to say that an SET preamp/amplifier is a highly desirable way to experience recorded music. Many of the pundits claim that most of the music is in the first watt. I'll know if that's true when I get these tubes processed and into a circuit.
 

tcmtech

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From what I've read and listened to I'd have to say that an SET preamp/amplifier is a highly desirable way to experience recorded music. Many of the pundits claim that most of the music is in the first watt. I'll know if that's true when I get these tubes processed and into a circuit.
Interesting comment.

Just for curiosity sake by chance have you had a full hearing nd assessment any time recently? Just curious being that the majority of the audiophiles who preach this audio purity stuff test out as having the hearing range and sensitivity of a blade of dry grass. :oops:
 

audioguru

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Hearing tests are still in the dark ages and do not measure above 8kHz because they concentrate on speech (ello, can you ear me, countdown one oo and ree?). I was amazed to see that my hearing has normal high frequency loss for my age (70). Luckily my new modern hearing aids go well above 8kHz.
 
Well, I'm not professing to be an audiophile nor am I preaching any "audio purity stuff". I do know that there are some fine sounding class A tube amps out there, though. In the end I'm just a guy building some triode vacuum tubes to use in a homebrew amplifier of some sort.
 

tcmtech

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Hearing tests are still in the dark ages and do not measure above 8kHz because they concentrate on speech (ello, can you ear me, countdown one oo and ree?). I was amazed to see that my hearing has normal high frequency loss for my age (70). Luckily my new modern hearing aids go well above 8kHz.
Maybe you need to come to the US being every hearing test I have ever had would go full spectrum 20 - 20KHz or until you failed.

Or did they just stop at 8 KHz for you being that is all the further up you are able to respond accurately to in an unaided testing condition? :rolleyes:

I top out at ~17.5 KHz on the tests myself and anything above that is below the minimum requirements to count.
 

audioguru

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Here is a standard graph for a hearing test for men and women at various ages. The graphs stop at the AM radio quality of 8kHz. I had the tests done at 3 different places and they all stop at 8kHz. The bottom end stops at 250Hz because speech does not produce the deep bass sounds of music.
 

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tomizett

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Sounds like an exciting project George... and sounds like you must have a very nicely appointed workshop.
Any pictures and information as you progress will be regarded with interest!
 

MrAl

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Hello all,

The way i understand it is that the audiophile who likes tube amps better may just be accustomed to any distortion that might have came from the tube amp, and after years of listening, it's not that if they heard the better sound of a good transistor amp they would like it because it reproduces the sound more accurately, it is more like they wont like to hear the real thing because they have been hearing something that has always been modified to some extent and they have long ago accepted as 'real'. So they may not LIKE to hear the real thing, even though scientifically it is better. It's another case of beauty in the eye of the beholder.

However, if a study was made of their favorite amplifier the sound of a transistor amplifier could be modified to exactly match the tube amp. If they still reject it then it's got to be pure bias toward the tube amp and nothing more than pure myth. Just such a study was done a few years back for professional violin players. The result was that they were so used to hearing the sound from a cheaper (not necessarily very cheap though) violin that they had a tendency to pick the cheaper violins as the better ones over the priceless antique Strats made by the masters.
So modern technology changed their ear slightly so they liked the modern instruments better than the old. That tells us that familiarity is preferred over anything else no matter how scientific it is.

There is a lot to sound too, by way of an amplifier. One of the things the guitar people like is when it gets to a certain level it will start to distort, and some of them look forward to that point. So it could get complicated, because the sound in that case would have to be replicated based on the whole range of the tube amplifier. One simplification however comes from the fact that there is 'probably' no storage involved. So a sound put through the amp at a certain level now will exit the same as if it is put through later.
 

audioguru

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They have made solid state amplifiers with the distortion and poor speaker resonance damping of vacuum tube amplifiers and they are liked by people who like vacuum tube amplifiers.
54 years ago my vacuum tubes amplifier sounded fine but need its output tubes replaced 3 months because they caused much more distortion. It was replaced 52 years ago by a solid state stereo receiver that I still use today and it still sounds fine.
 

atferrari

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Thinking of fidelity in reproduction of classic music, no matter transistor, valves or tubes, there is a simple trick: go to a qualified theater and listen. That quality should be the goal.

For the modern bands, I think you have to sit on the grass and listen. That is the "standard" of quality you want to achieve I guess. BTW, in my life, I went to a stadium once to listen Bee Gees.

I love the concept of double blind test for, call it music, wine or olive oil. It seems not much loved by those in the blah, blah, blah...

Tell me about religions; we all need some from an infinite catalog.
 

tcmtech

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Here is a standard graph for a hearing test for men and women at various ages. The graphs stop at the AM radio quality of 8kHz. I had the tests done at 3 different places and they all stop at 8kHz. The bottom end stops at 250Hz because speech does not produce the deep bass sounds of music.
Hmm. Maybe the test is different for us younger guys that they expect to have a wide range of hearing still intact. I'm pretty sure my grandpa's hearing tests stopped at 4 Khz being he was stone deaf above that.:oops:

Or maybe the tests for those of us who need to have certified health cards on us for our work (CDL and industrial work environment related ) are more in-depth than the basic public testing. I know the physicals I get to in order to keep my CDL and HazMat endorsement go way beyond the typical ones that most people get.;)
 

audioguru

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Thinking of fidelity in reproduction of classic music, no matter transistor, valves or tubes, there is a simple trick: go to a qualified theater and listen. That quality should be the goal.
My favourite concert hall is very old and has a sound system with boomy woofers and horn tweeters that sound awful (honk, honk). I betcha the amplifier uses vacuum tubes that are long overdue to be replaced.

My hearing aids were set with a trick for my fairly severe high frequency hearing loss. It did not sound correct. Because the trick took the high frequencies and shifted them down one octave "so I can hear the high frequencies better". They call it Sound Recovery but when I asked for it to be turned off then high frequency sounds were normal and much better. The audiologist did not turn it on, their computer thought I was a granny and let the teapot whistle be heard.
 
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