21 Jun
2004
21 Jun
'04
5:32 a.m.
From: "der Mouse"
<mouse(a)rodents.montreal.qc.ca>
Aside from legacy electronics (I have some pre-transistor-era equipment
lying around), for which transistor versions exist, I can't think of
any. The only thing I'm not sure of is the microwave oven - does the
microwave-generation-thingy depend on vacuum?
Hi
You see, knowledge already lost. Yes, a magnetron has a vacuum in it.
It has a filament and a plate ( with cavities in it ). While the
principles of these things can be found in books, much of the
mechanical and physical methods used to create these things is lost.
Partly because of the fact that manufactures don't tell all and
partly because no one is dealing with these kinds of things.
While it is claimed that the information is in books, there
are some feel things that rarely seem to make it into these
books. Can anyone tell me what controls the gain of a vacuum
tube ( other than someone that actually worked with these )?
Can anyone tell me how the grids must be placed for an electrometer
preamp tube and why? While we don't need these kinds of things today,
the knowledge of what makes these things work is still quite
valuable. This understanding can keep us from making mistakes
with other related problems. I can't say that these specific
things that I've mentioned will be the most important things
to remember but these are the types of tidbits that make
the difference when looking into new problem areas of the
future.
Those that understand these things will always be in demand.
Those that think they can ignore these kinds of things will
wonder why things are beyond understanding. This goes
for the entire range of things. You can't understand how
to think about things without actually thinking about things.
Dwight
Again,
I'm thinking in terms of vacuum tubes, and I can't see how
losing the knowledge of how they worked is going to affect the
future, or even the present for that matter.
I'm guessing that there is at
least one piece of equipment in your
house that relies on a vacuum tube to opperate that is not some sort
of display device. 
21 Jun
21 Jun
6:02 a.m.
Can anyone tell me what controls the gain of a vacuum
tube ( other than someone that actually worked with these )?
Er, I thought it was related to the distance of the grid from the cathode?
Can anyone tell me how the grids must be placed for an
electrometer
preamp tube and why?
If I knew what an "electrometer" was, I'd be doing better :-).
My tube background consists of taking television repair in high school. We
used tubes, but we sure didn't make them.
Actually, far and away the most common "repair" consisted of plugging them
back into the wall :-).
Those that understand these things will always be in
demand.
Those that think they can ignore these kinds of things will
wonder why things are beyond understanding.
In my experience, most people take it for granted that most things are
"beyond understanding".
Vince
6:07 a.m.
The only thing
I'm not sure of is the microwave oven - does the
microwave-generation-thingy depend on vacuum?
You see, knowledge already lost.
11:54 a.m.
Because I personally do not know it does not mean it's lost! (I don't
know how to extract nickel from ore, either, but has _that_ knowledge
been lost? Hardly!) Of course, it doesn't mean it hasn't, either....
Exactly just because you "know" how to do something doesn't mean you can
do it. I know how to make a statue or a nice dining room table but I
lack the finer skill to actually do it. That's where the skills are
being lost, these things take practise.
Dan
11:57 a.m.
Because I
personally do not know it does not mean it's lost! (I
don't know how to extract nickel from ore, either, but has _that_
knowledge been lost? Hardly!)
Exactly just because you "know" how to do
something doesn't mean you
can do it. I know how to make a statue or a nice dining room table
but I lack the finer skill to actually do it. That's where the skills are being lost, these
things take practise.
The skills that are being lost are the ones that cannot be taught but
instead must be learned, by doing, and doing, and doing. Those skills
it is no great catastrophe to lose, because each person must relearn
them anyway, "lost" or not.
/~\ The ASCII der Mouse
\ / Ribbon Campaign
X Against HTML mouse(a)rodents.montreal.qc.ca
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
12:37 p.m.
>>
>> The skills that are being lost are the ones that cannot be
>> taught but instead must be learned, by doing, and doing,
>> and doing. Those skills it is no great catastrophe to
>> lose, because each person must relearn them anyway, "lost" or not.
Except for the fact that it is much easier and effective to learn from a
master than from a text. This is why all of the "craftsmen" had
apprenticeship programs. Who you studied under often had more bearing on
your acceptance into the trade than your actual skill once you completed
your apprenticeship.
9:40 a.m.
You see, knowledge already lost. Yes, a magnetron has
a vacuum in it.
It has a filament and a plate ( with cavities in it ). While the
principles of these things can be found in books, much of the
mechanical and physical methods used to create these things is lost.
Please, people, please. Stop using the vacuum tube as an example of "lost
technology". It is a faulty example, at best.
We know "most" of the knowledge about vacuum tubes. We have most of the
*original* technical libraries from Eimac and RCA, and parts of many other
companies. We have the Proceedings of the IRE and other technical
journals. We have the research done by Tyne, who did it all while many of
the original tube guys (and tubes) were still around. We now have a
professional organization that does serious reseach on the history of
tubes. More stuff comes up every week. Basically, we know a hell of a lot.
For example, at the AWA TCA (Tube Collectors Association) meeting a couple
of years ago, we were all given a twenty-odd photocopy of all of the
Standardization Notices from RCA on how to make an type 45 triode. That
means ever last detail, down to what cement to use to glue the base to the
bulb.
I can think of NO glaring holes in our knowledge of tubes. The holes that
do come to mind are really relatively minor - details like how many 6N6Gs
Sylvania made during the fourth quarter of 1938, and did Triad ever try to
make Loctal tubes.
While it is claimed that the information is in books,
there
are some feel things that rarely seem to make it into these
books.
Yes, there is, and this is a problem. In reality, it tends to be a tiny
percentage of a given field's knowledge base. We should, however, strive
to fill these "feel thing" holes, as they are important.
Can anyone tell me what controls the gain of a vacuum
tube ( other than someone that actually worked with these )?
Can anyone tell me how the grids must be placed for an electrometer
preamp tube and why?
I think everyone on this list could find this information quite
easily. The knowledge is not lost.
William Donzelli
aw288(a)osfn.org
13 Jul
13 Jul
5:25 p.m.
William Donzelli wrote:
For example, at the AWA TCA (Tube Collectors
Association) meeting a couple
of years ago, we were all given a twenty-odd photocopy of all of the
Standardization Notices from RCA on how to make an type 45 triode. That
means ever last detail, down to what cement to use to glue the base to the
bulb.
But can you make a few of them?
I can think of NO glaring holes in our knowledge of
tubes. The holes that
do come to mind are really relatively minor - details like how many 6N6Gs
Sylvania made during the fourth quarter of 1938, and did Triad ever try to
make Loctal tubes.
Note tubes are making a come back since the quality of speakers have
improved since the 1960's.
Ben.
9:01 p.m.
ben franchuk wrote:
Note tubes are making a come back since the quality of speakers have
improved since the 1960's.
Ben.
I aggree that tubes are making a come back, but I don't understand what
that has to do with the quality of speakers...
Correct me if I'm wrong, but I understand that tube amplifiers sound
"different" than semiconductor amplifiers because certain harmonics are
supressed or distorted or something like that. But I don't understand
why people like that. With todays technology its simple and cheap to
build an amplifier with a bandwidth of 100KHz and a constant phase shift
over that range. Why would you listen to something less good then
"perfect" ?
Or am I completely ignorant/stupid here?
Bert
14 Jul
14 Jul
7:53 a.m.
Bert Thomas wrote:
I aggree that tubes are making a come back, but I
don't understand what
that has to do with the quality of speakers...
Correct me if I'm wrong, but I understand that tube amplifiers sound
"different" than semiconductor amplifiers because certain harmonics are
supressed or distorted or something like that. But I don't understand
why people like that. With todays technology its simple and cheap to
build an amplifier with a bandwidth of 100KHz and a constant phase shift
over that range. Why would you listen to something less good then
"perfect" ?
Or am I completely ignorant/stupid here?
Truth in advertising here ( while listening to a tube amp here )
is that most sales are towards a amp with the most power out into
a resisive dummy load.
1) Real speakers are inductive not a 200 watt 4 ohm resistor.
2) Lots of feedback is used to keep a transistor amp linear.
3) Sine waves in a lab is different from real music.
4) People buy amps to be loud for loud rock music.
Bert
9:09 p.m.
You are making the mistake in thinking that because an op-amp provides
linear amplification across a wide range of frequencies it produces the
'nicest' sound.
The human ear is not a linear receiver ;)
It is simply down to what you like - and valves colour the sound in a
way that sounds 'nice' to most people.
Have you ever heard music out of a whirlitzer - hopelessly coloured but
somehow good.
Feel free to disagree - I've been known to be wrong!
Mark.
Mark Wickens
Rhodium Consulting Ltd
-----Original Message-----
From: cctalk-bounces(a)classiccmp.org
[mailto:cctalk-bounces@classiccmp.org] On Behalf Of ben franchuk
Sent: 14 July 2004 20:53
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Modern Electronics (was Re: List charter mods &
headcount... ;
Bert Thomas wrote:
I aggree that tubes are making a come back, but I
don't understand
what
that has to do with the quality of speakers...
Correct me if I'm wrong, but I understand that tube amplifiers sound
"different" than semiconductor amplifiers because certain harmonics
are
supressed or distorted or something like that. But I
don't understand
why people like that. With todays technology its simple and cheap to
build an amplifier with a bandwidth of 100KHz and a constant phase
shift
over that range. Why would you listen to something
less good then
"perfect" ?
Or am I completely ignorant/stupid here?
Truth in advertising here ( while listening to a tube amp here )
is that most sales are towards a amp with the most power out into
a resisive dummy load.
1) Real speakers are inductive not a 200 watt 4 ohm resistor.
2) Lots of feedback is used to keep a transistor amp linear.
3) Sine waves in a lab is different from real music.
4) People buy amps to be loud for loud rock music.
Bert
10:35 p.m.
Mark Wickens wrote:
You are making the mistake in thinking that because an op-amp provides
linear amplification across a wide range of frequencies it produces the
'nicest' sound.
The human ear is not a linear receiver ;)
It is simply down to what you like - and valves colour the sound in a
way that sounds 'nice' to most people.
Perhaps, but that should not be the job of the amplifier, but of the
'source', whatever that may be.
And now I come to think of it: it should be possible to record a CD,
feeding the ADC with a signal from a tube amp, and have that "nice"
sound out of a "perfect" transistor amp.
Bert
11 p.m.
New subject: Amplifiers?
>> And now I come to think of it: it should be
possible to
>> record a CD, feeding the ADC with a signal from a tube amp,
>> and have that "nice" sound out of a "perfect" transistor amp.
Well, NO.....
The "issue" is that the differences in on-linearities ("color") are
also a
function of volume.
While this is a very subjective matter, it is quite real.
As the sound enginer for a band, I did a number of tests on the frequency
analysis (including phase, attack, distortion, etc) on a number of
performances. Given the same material being played at different venues, the
profiles were quite distinct.
In recent years, a number of audio equipment manufacturers have released DSP
based products that mimic the behaviour of specific tube based amplifiers.
While some purists disagree, the majority of blind sound tests have
confirmed that these are indistinguasible from the originals to the human
(trained) ear.
So a "perfect" amplifier is not really what is desired in most conditions.
15 Jul
15 Jul
2:05 a.m.
New subject: Amplifiers?
"David V. Corbin" wrote:
The "issue" is that the differences in on-linearities ("color") are
also a
function of volume.
While this is a very subjective matter, it is quite real.
As the sound enginer for a band, I did a number of tests on the frequency
analysis (including phase, attack, distortion, etc) on a number of
performances. Given the same material being played at different venues, the
profiles were quite distinct.
In recent years, a number of audio equipment manufacturers have released DSP
based products that mimic the behaviour of specific tube based amplifiers.
While some purists disagree, the majority of blind sound tests have
confirmed that these are indistinguasible from the originals to the human
(trained) ear.
So a "perfect" amplifier is not really what is desired in most conditions.
Though I learned a lot from this discussion, I still don't see why you
would not change the "color" at the input of a "perfect" amp instead
of
letting the amp determine the "color". Unless those DSPs compensate for
the distortion in the "non-perfect" amp, those DSPs need a "perfect"
amp
as well. Or wrong again?
Bert
1:24 a.m.
New subject: Amplifiers?
>>
>> Though I learned a lot from this discussion, I still don't
>> see why you would not change the "color" at the input of a
>> "perfect" amp instead of letting the amp determine the
>> "color". Unless those DSPs compensate for the distortion in
>> the "non-perfect" amp, those DSPs need a "perfect" amp as
>> well. Or wrong again?
If the Volume is going to be changed at the amplifier, then the alterations
need to be done at the amplifier.
If you are going to keep the amplifier at a fixed gain, then the alterations
can be done at the input.
The "problem" with the latter is dynamic range. Hard to have a perfect amp
that can deal with outputs from a "whisper" to pumping out kilowatts.
5:58 p.m.
New subject: Amplifiers?
David V. Corbin wrote:
In recent years, a number of audio equipment
manufacturers have released DSP
based products that mimic the behaviour of specific tube based amplifiers.
While some purists disagree, the majority of blind sound tests have
confirmed that these are indistinguasible from the originals to the human
(trained) ear.
So a "perfect" amplifier is not really what is desired in most conditions.
Except for me of course. I want a transparent amp but not a colored one.
Amps I am finding out have different factors that you can't find out in
regular sales information. I listen to music 24/7 so a less distorion is
required. Things like a regulated power supply is something few amps
have. Qaulity components is a second factor. Good music is a third
factor from a good source like new LP's. CD's have too low a sampling
rate for good music.
Ben.
Some intersting thoughts for reading here.
http://www.nutshellhifi.com/index.html
16 Jul
16 Jul
2:36 a.m.
New subject: Amplifiers?
Here's some more reading on amplifiers, and "HiFi Mysticism"
http://www.diyaudio.com/forums/showthread/t-12752-p-6.html
http://www.audioasylum.com/scripts/t.pl?f=general&m=311853
Both sites are great for all sorts of information on HiFi, from both
subjective and objective camps.
Personally, and all other factors being equal (Good quality components, not
state of the art but not broken designs, either) I find the factors
affecting the sound break down like this:
40% speakers/room accoustics
50% source material
10% everything else (system components, AC quality, etc...)
Keeping things quasi-on-topic, I've decided it's time to build a show
system, with blinkenlights and excessive switches and knobs and everything.
I've settled on the AOpen AX4GE Tube-G motherboard, if for no other reason
it's probably the first computer to have a tube on the mainboard since the
UNIVAC days. I can't find where to buy these beasts, however, so does anyone
know where to find maybe 1-2 year old computer surplus or closeouts? For
further retro-fun, I'm planning on putting in a POST code analyzer with big
LED display on the front of the case (ala IBM RS/6000 systems), one of those
retro-looking fan controllers, and Corsair XMS memory with LED status
indicators. Window on the side, of course :) Then I'll run Linux on it with
hercules and a fullscreen 3270 emulator plugged into OS/360. It'll be fun to
run at lan parties :)
PS: My system- Sumiko turntable, Sonic Frontiers Line 1 preamp, NAD 214 amp,
Audio Alchemy ACD1 CD player, Denon DVD-1600 DVD player, Magnepan MG-1.4
speakers, homebrew phono preamp and AC filters. Almost all used, sounds
fantastic.
----- Original Message -----
From: "ben franchuk" <bfranchuk(a)jetnet.ab.ca>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk(a)classiccmp.org>
Sent: Friday, July 16, 2004 1:58 AM
Subject: Re: Amplifiers?
Except for me of course. I want a transparent amp but
not a colored one.
Amps I am finding out have different factors that you can't find out in
regular sales information. I listen to music 24/7 so a less distorion is
required. Things like a regulated power supply is something few amps
have. Qaulity components is a second factor. Good music is a third
factor from a good source like new LP's. CD's have too low a sampling
rate for good music.
Ben.
Some intersting thoughts for reading here.
http://www.nutshellhifi.com/index.html
4:55 p.m.
New subject: Amplifiers?
Jason McBrien wrote:
Here's some more reading on amplifiers, and
"HiFi Mysticism"
http://www.diyaudio.com/forums/showthread/t-12752-p-6.html
http://www.audioasylum.com/scripts/t.pl?f=general&m=311853
Both sites are great for all sorts of information on HiFi, from both
subjective and objective camps.
Personally, and all other factors being equal (Good quality components, not
state of the art but not broken designs, either) I find the factors
affecting the sound break down like this:
40% speakers/room accoustics
50% source material
10% everything else (system components, AC quality, etc...)
Keeping things quasi-on-topic, I've decided it's time to build a show
system, with blinkenlights and excessive switches and knobs and everything.
I've settled on the AOpen AX4GE Tube-G motherboard, if for no other reason
it's probably the first computer to have a tube on the mainboard since the
UNIVAC days. I can't find where to buy these beasts, however, so does anyone
know where to find maybe 1-2 year old computer surplus or closeouts? For
further retro-fun, I'm planning on putting in a POST code analyzer with big
LED display on the front of the case (ala IBM RS/6000 systems), one of those
retro-looking fan controllers, and Corsair XMS memory with LED status
indicators. Window on the side, of course :) Then I'll run Linux on it with
hercules and a fullscreen 3270 emulator plugged into OS/360. It'll be fun to
run at lan parties :)
PS: My system- Sumiko turntable, Sonic Frontiers Line 1 preamp, NAD 214 amp,
Audio Alchemy ACD1 CD player, Denon DVD-1600 DVD player, Magnepan MG-1.4
speakers, homebrew phono preamp and AC filters. Almost all used, sounds
fantastic.
Well you forgot one thing ... Room Accoustics
http://mywebpages.comcast.net/kidder/Audio/Room/PANEL/Panels.htm
http://www.geocities.com/jonrisch/a.htm
http://ic.net/~jtgale/diy2.htm
Ben.
PS: A real computer with the blinking lights.
http://timefracture.org/
19 Jul
19 Jul
8:19 p.m.
New subject: Amplifiers?
ben franchuk wrote:
David V. Corbin wrote:
So you listen while hacking old hardware? I haven't seen you in
classiccmp recently.
Jim Davis.
In recent years, a number of audio equipment
manufacturers have
released DSP
based products that mimic the behaviour of specific tube based
amplifiers.
While some purists disagree, the majority of blind sound tests have
confirmed that these are indistinguasible from the originals to the
human
(trained) ear.
So a "perfect" amplifier is not really what is desired in most
conditions.
Except for me of course. I want a transparent amp but not a colored one.
Amps I am finding out have different factors that you can't find out
in regular sales information. I listen to music 24/7 so a less
distorion is
required. Things like a regulated power supply is something few amps
have. Qaulity components is a second factor. Good music is a third
factor from a good source like new LP's. CD's have too low a sampling
rate for good music.
Ben.
Some intersting thoughts for reading here.
http://www.nutshellhifi.com/index.html
20 Jul
20 Jul
6:48 a.m.
New subject: Amplifiers?
JimD wrote:
ben franchuk wrote:
So you listen while hacking old hardware? I
haven't seen you in
classiccmp recently.
Nope, only when reading my email. :)
Jim Davis.
Since I don't have access to a real classic computer
I plan to build my own. Now is a homebrew computer
with the da blinking lights like found here
http://timefracture.org/D16.html and
http://www.homebrewcpu.com/ on topic or not?
Ben.
7227
days inactive
7256
days old
20 comments
11 participants
participants (11)
-
aw288＠osfn.org -
bert＠brothom.nl -
bfranchuk＠jetnet.ab.ca -
dan_williams＠ntlworld.com -
dvcorbin＠optonline.net -
dwight.elvey＠amd.com -
jbmcb＠hotmail.com -
jimmydevice＠verizon.net -
m.wickens＠rhodium-consulting.com -
mouse＠Rodents.Montreal.QC.CA -
vrs＠msn.com