In a vacuum tube, nobody can hear you scream.

[tectak]

After much tyresome googling: I have effected, all without the
help of undue modesty, a creative explication of your odeous olio
(sans poached pachyderm). It was Childe's play.

If your interpretation comes anywhere near mine, I'd consider
the damn thing a good poem except for the last line-and-a-quarter
(which my interpretation excludes).

"Tomorrow I will wake to blindness, rise, and tread my eyes
into the dirt."  

Inserting old movie clichés into a poem, even when intended as
homage or oblong irony, is pretty lame dude.

But, excepting for the fact that it ends the poem, it's really just a nit.



P.S.
Princess Dido from Tyre was a rarity,
Her bum Carthage's source of prosperity;
A maximal flat
Was obtained when she sat,
Her posterior proved her posterity.


P.P.S.  
Pentodes are noisy
Triodes are sweet
But power corrupted
Now they're obsolete

Your PPS is far from true,
though pentode's glow is not now blue
and triodes still are best for bass.
Pity they're still made from glass.

Oh, and they still get as hot as this thread.

tectak http://www.amazon.co.uk/s/?ie=UTF8&keywo...9odjwm3q_b

[rayheinrich]

Your PPS is far from true,
though pentode's glow is not now blue
and triodes still are best for bass.
Pity they're still made from glass.

Oh, and they still get as hot as this thread.

tectak http://www.amazon.co.uk/s/?ie=UTF8&keywo...9odjwm3q_b

See General Discussion: "In a vacuum tube, nobody can hear you scream."
-ray

[rayheinrich]

Moved from Poetry Forum › Serious Workshopping > "The Prophet" thread.

(in response to Leeanne's poem "The Prophet")
...
in studio six.  Behind my lids, miles of  Beware the man of two books. I could draw
the power output stage, class A, push-pull pentodes, no neg. feedback of the studio
six all-vacuum tube amplifier...too obscure? Too esoteric? Too much jargon? Well,
you started it Smile Still, I am mythtified ( and if that ain't a word it should be).

P.P.S.  
Pentodes are noisy
Triodes are sweet
But power corrupted
Now they're obsolete

Your PPS is far from true,
though pentode's glow is not now blue
and triodes still are best for bass.
Pity they're still made from glass*.

http://tiny.cc/vacuumnouveau

Oh, and they still get as hot as this thread.

Sure, they're not non-existent, but in this day of straight-to-digital
(their inputs, not our brain [though that's coming]) 50mz over-sampled
1-bit a/d parametric amplifiers they're technically obsolete.

*Vacuum tubes (valves to you Brits) don't just come in glass envelopes.
They have metal, metal/ceramic (like the 12K watt one [a triode] that was
used in an FM transmitter I used to repair [it was about 12" high and 6"
in diameter]), and quartz ones as well. I came across the quartz one when
repairing the instrumentation for a scientific furnace at the U.S. National
Bureau of Standards (now called NIST). Its chief claim to fame was its
ability to maintain temperatures in the 800ºC (1500ºF) range to an accuracy
of +/- .05 ºC . It used a vacuum tube (custom-made for this very purpose)
with an envelope of quartz so that it could operate within the furnace.
Its conducting elements were made of invar and it required no filament as
the cathode glowed (as well as everything else in the furnace) quite nicely
on its own.

Obsolete but still running: I use a Dynaco PAS 3 vacuum tube pre-amp I built
from one of their kits a zillion years ago. One of its inputs is connected
to an AR AX turntable (though I am not a vinyl freak; I much prefer the quiet
of the quiet passages on CD's).

[Magpie]

I don't know about other uses but for guitar amplifiers the valve sound is still the preferred sound by electric guitarists for it's warmth in the way it produces low frequency harmonics. Also because valves react differently depending upon how much energy/power you put through then they become an expressive extension of the guitar which feels more organic than solid state transistors. I've been assured that the reason for all this is because valves work in a non-linear way, which I'm assuming is the same as saying it 'feels organic' which is good enough for me. I can hear it and I know.

The main drawback to valves is the weight which is ok if you don't have to move it, but usually guitar amps see a lot of miles on the road so it becomes an issue.

Digital attempts to replicate the same sounds and the feeling of valve amps always have and probably always will fall short. And it's not that I secretly despise digital like a lot of others but in this aspect for valve guitar amps there are very good reasons for why they can't match up, mainly the response that you get back. It's the same with effect pedals, digital software has come up with amazing packages that give you 100's of effects for virtually nothing, but some people are still happier paying over £50 for just one pedal and one effect. 

All in all I'm glad I just play acoustic guitar so it don't affect me at all these days, but it used to.

[rayheinrich]

I'd give you 10 to 1 odds that it's possible to replicate the sound. I suspect that no one's
willing to take the time/$$ to do it. If something comes close and most people are willing to buy it,
why spend $$ on the 5% who can tell? Another disincentive, I'd guess, is that there's a higher profit
margin on the tube equipment.

The sound of organs using Leslie speakers (a baffle under the speaker is actually rotated by a motor)  
are quite a bit harder. I read an article by an acoustic engineer a while back (2001 to 2005 I'd guess )
saying that it was a bit beyond what was feasible at the moment. Sound samples from the actual organs
worked pretty well, but connecting the individual samples hadn't been done successfully.

Another problem is there are no (or not many, don't know) studies using blind listening tests.
When someone knows what they're listening to, the subjective bias (it's the same with
psychiatric drugs) is too great to get reliable results.

I do know there have been studies where the sound of vinyl records was compared with
CD sound that had had a little sputtery white noise mixed in. No one could tell them apart.

With MP3 (128 kbps), on the other hand, experienced listeners can tell the difference.

As for me, I'm willing to swear that that Dynaco tube pre-amp of mine is just plain sweeter.
While I don't believe myself for a second, I'm happy to bask in the placebo effect.
( Cats, by the way, overwhelmingly prefer tubes: Every time I fire up my Dynaco, it's only
a matter of minutes before there's a cat lying on top of it.)

When the power fails, acoustics still work. It's the same with my typewriter.

[Magpie]

I do know there have been studies where the sound of vinyl records was compared with
CD sound that had had a little sputtery white noise mixed in. No one could tell them apart.

With MP3 (128 kbps), on the other hand, experienced listeners can tell the difference.

I should warn you that you may regret giving me an opportunity to talk about psychoacoustics because once I've started it is practically impossible to stop me.

Lets start with binaural beats...

[billy]

lets not

[rayheinrich]

I should warn you that you may regret giving me an opportunity to talk about psychoacoustics because once I've started it is practically impossible to stop me.

Lets start with binaural beats...

My hippy sister in CA goes on about them. Happening to have two signal generators
lying about, I tried it. Nice effect, but didn't see God(s). I guess my brainwaves weren't feeling
entrainable that day. Ask me about bat (the mammal) detectors. Have done what you might
call a bit of psychoacoustisizing there (single note cords).

... but I digress...
I'm more than willing to hear ( ) you ranting about binaural beats. Convince me.

[Magpie]

My hippy sister in CA goes on about them. Happening to have two signal generators
lying about, I tried it. Nice effect, but didn't see God(s). I guess my brainwaves weren't feeling
entrainable that day. Ask me about bat (the mammal) detectors. Have done what you might
call a bit of psychoacoustisizing there (single note cords).

... but I digress...
I'm more than willing to hear ( ) you ranting about binaural beats. Convince me.

Well I wasn't really being serious but... Tell your sister no. It's not true. I'm fairly certain that it had been disproved because all of the results where it was shown to work were called into question when it was pointed out that headphones were used and because headphones have got magnets inside of them then they would affect whatever equipment was used to detect the brain waves. I think that they tried the test again using headphones without magnets and the same results weren't achieved.

The whole concept seems a bit bizarre in the first place because essentially we are talking about two notes that are slightly out of tune with each other. In some sense it's not real and is only a perceived phenomenon due to the fact that the brain can't process two tones that are so close to eachother. Although saying it's not real and only perceived is a bit hard to comprehend when the effect is very obvious and as well as being heard the fluctuation can be felt in the ear drums. At one point in time I would have said that the only real use for binaural beats was in helping musicians to tune instruments, which is what I've always used it for, however after recently reading a book about acoustic weapons it would seem that various governments around the world have realised that the phenomenon can be used and has been used to disperse crowds. It makes sense that it would work because even at low volume it can be quite distracting and annoying but when used at much higher volumes I can imagine it would be very disorientating. When I read it my first thought was "bastards", how can they take something so simple and natural and turn it into a weapon. On the other hand faced with a crowd of people who were deaf in one ear their weapon would be hopeless. But out of all the possibilities that armies have looked at for acoustic weapons it is one of the milder ones that are possible. The common 'acoustic deterrent' that they've been using for years is to play a noise that is of a frequency that only under 16's can hear. They play it at train stations and shopping malls to stop teenagers loitering. However teenagers have turned the tables and they ingeniously use it as a ring tone on their mobiles that teachers can't hear.

Bats??? Sounds interesting. I know a little bit about how they use Doppler shift but probably not enough. Any mammal that has evolved to have the ability to fly is definitely worthy of respect. In fact they are the only mammal that has evolved to have the ability to fly (flying squirrels don't fly they glide). Whereas any mammal that spent a long time making little blindfolds for bats so they could prove that bats use sonar is probably a bit mad as well as slightly genius.

I'm all ears.

[rayheinrich]

Well I wasn't really being serious but...

I never am.
I looked on the web for some binaural beat audio recordings.
There were a lot that said they were, but I couldn't find one that really was.
(But I didn't search that hard.)

In a real binaural beat audio recording, when you listen to only the left earphone
you would hear, say, 1000hz . When listening to only the right earphone you would
hear 1200hz. But when you put them both to your head you would hear 200hz as well.
All the damn recordings I could find had already mixed the frequencies. Each earphone
already had all three frequencies.

Binaural beats may not entrain your brain, but visual ones actually do.
Google "Gysin dreamachine" .
I tried one that a friend made a long time ago. It worked great for him.
It just gave me a headache so I had to take drugs instead.