John Curl's Blowtorch preamplifier part II

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I did nod toward Grayslake Monday, as once again I was just passing through. I'm planning another visit soon on the way back from Cal Tech after reviewing their next instrument package.

We'll have some bottles standing. If we time things right, I may be able to arrange us catching one of the most astonishingly wonderful guitarists I've ever heard. Make sure you bring a meter along to distract you while he's playing.
 
I once met Jim Williams about 25 years ago at his office at LT, along with Walt Jung, who worked there at the time. Nice guy, very smart, practical engineer.
I was told that LT in general hated audiophiles because they were too 'fussy' and sometimes their criticisms of certain parts made little measurable sense, like copper leads vs kovar leads, etc. Not enough money in it (high fidelity) to waste designers time on exotic audio products. Thank goodness National went a different direction, in spite of Pease, who claimed that he was a lousy listener, and like many here, hated deviation from the norm in wires, etc.
 
With audio we facilitate the production and reproduction of music, so that is pretty close to something to evoke soul, however that is defined. Your drive seems to be more one of a problem solver, mine a bit more of an artist. Neither of us are likely to fit the stereotype much loved by some, of geeks with pocket protectors, adhesive-taped black-rimmed glasses, and with white lab coats and clipboards.

Yes and no. Sometimes it really does feel like all the tools (intellectual or physical) at my disposal are paintbrushes to solve problems. Perhaps that was what you're trying to say and I missed it. Either way, as analytical as it may be, there's still something very human about it.

But yes, we certainly don't fit the clean boxes people wont to put people into (guilty as charged, as much as I might fight it).

Mark--I'd not think water makes a good enough fast neutron absorber, and thus why you couldn't focus the beam well enough to actually do tissue ablation? But, yes, 10 years on a project is a hard lump to swallow.
 
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Mark--I'd not think water makes a good enough fast neutron absorber, and thus why you couldn't focus the beam well enough to actually do tissue ablation? But, yes, 10 years on a project is a hard lump to swallow.

We used motorized tungsten collimators for beam shaping. As far as humans being similar to water, the beam does scatter in tissue. But there is the same problem with most other forms of radiotherapy to some extent or other. It's not unworkable with neutrons. The main problem is cost verses efficacy. Neutrons don't work well enough to justify the cost, even for specially selected tumors such as salivary gland.
 
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Glad that this was brought up. ;)

Perhaps the pink elephant in the room is going to be "imaging" along with "soundstage", "ambience" and the other terms that are used to describe how the sound is perceived.

It's the one thing that has nil correlating whatsoever to any parameterized measurement(s).

Well a few serious researchers might have some issues with you calling their life's work 'nil'.

Now of course mixmonkey school teaches you how to move sounds left, right, up and down plus the out of phase trickery.
 
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Yes and no. Sometimes it really does feel like all the tools (intellectual or physical) at my disposal are paintbrushes to solve problems. Perhaps that was what you're trying to say and I missed it. Either way, as analytical as it may be, there's still something very human about it.
I got that your focus is a bit more service-oriented than mine (although in other activities I manage some more direct help). The story about the Apollo exercise was illustrative of that I thought.

It gets to be an old saying, but I'm still trying to figure out what to do when I grow up. I doubt that it will be to become a prize-winning audio designer. It is even more unlikely that I'll be saving lives with better I-V converters or phono preamps.
 
billshurv,
I imagine that Toole and Linkwitz would both take offense to those comments. There has been plenty of analysis of speakers and room interaction that has been published. I think that the conversation has just gotten to be a Pi**ing match at this point with no end point in sight.

Since everything in audio sounds the same and imaging is a figment we might as well just use two 9-transistot radios, one on each side of our heads! :D
 
We used motorized tungsten collimators for beam shaping. As far as humans being similar to water, the beam does scatter in tissue. But there is the same problem with most other forms of radiotherapy to some extent or other. It's not unworkable with neutrons. The main problem is cost verses efficacy. Neutrons don't work well enough to justify the cost, even for specially selected tumors such as salivary gland.

Gotcha. Thanks for adding context!
 
I got that your focus is a bit more service-oriented than mine (although in other activities I manage some more direct help). The story about the Apollo exercise was illustrative of that I thought.

It gets to be an old saying, but I'm still trying to figure out what to do when I grow up. I doubt that it will be to become a prize-winning audio designer. It is even more unlikely that I'll be saving lives with better I-V converters or phono preamps.

Ah, yes, you did hit the nail on the head then. Sorry if I missed your gist.

And there's a definite part of me that hopes I never figure out what I want to do when I grow up.
 
Unless physics has changed a stereo signal starts out as an electrical one, voltage/current vs time, no free parameters.

OK so you haven't taken any data on phase and amplitude vs. polar pattern and even tried to tie it into actual (no peeking) listening tests. Or maybe room/speaker effects, the reflection off that 20' high brick wall on the right can't possibly affect what I hear.

As far as I can tell the whole purpose of the line of discussion is to slip in the Bybee, etc. BS.

Guess you can't see beyond your pet peeve with Mr. Bybee?
As I said, don't care one way or another WHAT causes there to be a perceivable difference... etc. Just read back to what I actually said.

If you think that the sound of a system can be predicted by what you just cited, then you're in the wrong biz, IF you were able to do that.

Nothing in that is going to predict for a second what the perception of the soundfield will be like. Imaginary brick walls in your room or not.

Nothing in that is going to predict why one DAC sounds kind of "flat" dimensionally, while another may appear to give front to back depth, or one may sound "compressed" while another may sound "dynamic". Etc.

However, you, and no one you know has ever heard that, much less any other differences between (reasonably well spec'd) DACs, right?

Sibilence.
Which measurement predicts sibilence?
I've seen systems with apparently great specs where the sibilence was annoying. You've not I guess ever heard annoying or excess sibilence?
While other systems seem to magically "resolve" that same energy into a natural sounding presentation with all the same energy but without the annoyance (to state it in simple terms).

How about one DAC seems to express "sibilence" while another not?
Or an amp??
Nope, could not happen, never has happened, and IF it did happen there would have to be some measurable thing substantially askew. Right?

(what would that measurable thing be?)

No one reading or posting has EVER had any issues with sibilence in any system? Certainly never in their own. Yep. Never.

Or, maybe "sibilence" is simply unavoidable, it's part of the recordings and a result of microphones and electronics working properly and something that "ought" to be there? Is that it??

And, if it is NOT, then something is WRONG...??? :eek::eek::eek:

_-_-
 
Which measurement predicts sibilence?

I think different physical things could cause one to experience what you are calling "sibilence" when listening. Some things that come to mind: (1) EQ, (2) Harmonic distortion, (3) Some kinds of clock jitter depending on the spectrum.

The things I listed and the things engineers want (need) to talk in terms of are things that be measured and that are described in terms of the physics involved. On the other hand, sibilence is a an experience, the result of System 1 processing in the brain. Experiences are hard to measure, at least for now. It may be a subject for basic scientific research, but engineering is mostly applied science. Thus at this point in time, it is probably unreasonable to ask engineers to work in terms of providing a specified mental experience result. Not going to happen anytime soon.
 
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