John Curl's Blowtorch preamplifier part II

Status
Not open for further replies.
Dutchie ,

Deep cycle or dry cell Battery ....... :)

Marce,

sorry about that, there are a great many talented folks originating from GB, and I do enjoy many parts of the UK and it's culture.

Part of the judicial system here is totally bonkers as well, despite having had the luxury of formal training in general and civil law, I've funded various Bentley accessories over the years.
In my experience, the majority of attorneys/barristers have the intellect of a highly overpaid secretary (who flunked math 101).

(just finished my two year probation period for battery a number of weeks ago, more the type to stab the Bentley driver than decanting petrol handouts. Though for lawyer Continentals, I'd gladly make time for a thorough Vic Vega session in the garage :clown:)
 
These days in the USA with medical advertising we have a very mixed bias situation. The drug company wants you to suggest to your doctor that you want to try a certain medication to take care of a single medical condition, telling you that this certain medication will alleviate the problem at the same time listing up to ten side effects such as sudden death, stroke and other side effects that can be worse than the cure. How does this bias you in a positive or negative way when you are getting such mixed signals?

The same thing must be looked at in some of the audio claims we hear, perhaps they can improve one problem while causing another unknown phenomena at the same time, but here you do not hear of negative side reactions as you would in a clinical medical situation. If you have a large enough group to do an abx test and you can show that statistically the group can identify a change doesn't that show an effect whether positive or negative? Now what is positive and what is negative is where we will have little agreement unless it is an egregious change for the worse such as very high distortion. But just as one person will like a piece of art and another will deride that as utter trash how do you ever test for best of sound, or even small changes whether good or bad?

In medicine we are looking for a particular effect when testing a new drug, but many times it is the side effects that are not known for years or even generations. This same shortfall is similar to testing audio with known test methods while not understanding that there may be other unknown phenomena that we just haven't created the test to find at this point.
 
Deep cycle or dry cell Battery

Ducky,

you should know better than to ask a roughian mariner such a question.

(A temporal bone fracture by hitting once counts as a single deep cycle, imo. Though it's been my 30-year experience that it's always dry cells who apply at a heavy hitter for a jump start. Somewhat of a DBT. A mouth cavity-search for DNA, I consider rather uncivilised, and a very appalling tradition, by the way)
 
Last edited:
Disabled Account
Joined 2012
Well, again, if you want to use "data" of the same quality as "data" indicating alien abductions, you can arrive at conclusions of the same quality.

yes? and so? Obvious. Where's the good meta-data?

I'm still not sure what a "DBLT" is; some sort of sandwich?

Double Bacon-Lettuce-Tomato or did you really mean Database Literals?
[Conceptual Modeling -ER2002]

Thx-RNMarsh
 
Last edited:
... then the meta-analysis of listening data on electronics shows exactly what you'd expect- humans are very sensitive to interchannel timing, frequency response, and level. They are indifferently sensitive to distortion, slightly sensitive to phase (at certain frequencies and levels of phase change), and absolutely insensitive to "magic" factors.
Intended as a straighforward question, what results have come in about noise injected into the signal - random, semi-random, highly correlated, at different constant levels, and following the amplitude envelope of the signal?
 
Intended as a straighforward question, what results have come in about noise injected into the signal - random, semi-random, highly correlated, at different constant levels, and following the amplitude envelope of the signal?

As a first order measure a device under test may be placed in a metal enclosure and fed from as clean a power supply as possible. The output noise can then be compared to either a "normal" power line or one with a known quantity and type of noise.

I do have the ability to do this but my getting to doing more research on it is at least a year or more down the road.

ES
 
Really? I find that hard to believe. Truth is certainly a defence to defamatory statements here in NZ and we are a common law based system very similar to England and Australia.

A defense is nice. Although most of my legal experience is collecting money a low cost lawsuit is $10,000 and can run to $500,000 without much effort.

Last bill was $32,000. The low cost was because it settled quickly with virtually no opposition, as there were no issues in dispute!

J

My experience is that criminal layers don't need to be very bright as their legal skills and typical clients are not very demanding. I had need of one once as I wanted to go after a civil suite defendant with additional criminal charges when certain issues were discovered.

The criminal lawyers interviewed were not impressive. My civil lawyer just about wet the floor rather than going after the reasonable powerful folks with criminal charges.
 
Last edited:
A defense is nice. Although most of my legal experience is collecting money a low cost lawsuit is $10,000 and can run to $500,000 without much effort.

Last bill was $32,000. The low cost was because it settled quickly with virtually no opposition, as there were no issues in dispute!

Ouch! Yes even in NZ legal costs can be high.

By the way I was correct to be suspicious about SY's assertion regarding the absence of the defence of Truth in England (you can't say the UK, Scotland has a different system though I am sure has the same defence available). In short, truth is an absolute defence to a statement claimed to be defamatory even if the truthful statement was published maliciously, the defence logically follows from the definition of defamation really, but I am wandering more than slightly off topic.
 
just about wet the floor

In order of brightness: fiscal, general, criminal, family law, youth criminal lawyer.

Though that's general, I've had a lot of contact with a criminal defense lawyer of the top 5 overhere, over an extensive period of time (not as a client, btw :clown:) Though as decadently unconventional as your's truly, a really smart guy.
http://www.refdag.nl/polopoly_fs/theohiddema_anp_1_626646!image/4071541234.jpg

I've yet to meet an engineer, who does not totally loathe lawyers, and despise their profession.
Worst one can happen, is score a law fraternity slot during university years, and find her at the other side of the table, during an alimony battle.
 
In order of brightness: fiscal, general, criminal, family law, youth criminal lawyer.

Though that's general, I've had a lot of contact with a criminal defense lawyer of the top 5 overhere, over an extensive period of time (not as a client, btw :clown:) Though as decadently unconventional as your's truly, a really smart guy.
http://www.refdag.nl/polopoly_fs/theohiddema_anp_1_626646!image/4071541234.jpg

I've yet to meet an engineer, who does not totally loathe lawyers, and despise their profession.
Worst one can happen, is score a law fraternity slot during university years, and find her at the other side of the table, during an alimony battle.

These are the best, just make sure you keep the pictures, best defence ...:D
 
The criminal lawyers interviewed were not impressive. My civil lawyer just about wet the floor rather than going after the reasonable powerful folks with criminal charges.
(Another) Something I'm not understanding. The state goes after folks with criminal charges. A citizen can hire lawyers and private investigators, but evidence gathered is turned over to gov't officials for prosecution. I'm guessing that is what was meant.
And of course defamation is a civil matter and won't be heard in a (USA) criminal court.
 
(Another) Something I'm not understanding. The state goes after folks with criminal charges. A citizen can hire lawyers and private investigators, but evidence gathered is turned over to gov't officials for prosecution. I'm guessing that is what was meant.
And of course defamation is a civil matter and won't be heard in a (USA) criminal court.

No when criminal activity is proven in a civil case there may be an application of what is known as RICO. That triples the award and in this case would have forced the US attorney to do something after they declined to get involved. (Strong hint of politics as the lead investigator was transfered to a very similar issue in another region where the dominant folks were from the other political party.)
 
A high percentage of readers here would be getting the Audio Precision newsletter; for those who don't, something of interest - a memory of a 'disturbing' artifact from when the company moved into new quarters:

Almost immediately after moving we began to experience failures of certain bench tests that are performed by our technicians during the course of product assembly and adjustment. After some research, we discovered our new building had some extremely large magnetic fields in the production area, almost as if it was haunted. These fields coupled high levels of hum into our products that were causing the test failures. AP products are designed to reject reasonable levels of stray magnetic fields that would typically be encountered in a lab or production environment. However the magnitude of the fields we faced were at least 20 dB worse.

We ultimately discovered that several of our AC outlets had been wired incorrectly, having their neutral and ground connections swapped. This is a big no-no from the safety viewpoint, but it also caused all of the neutral currents in a particular circuit (outside of our production area) to return through the safety ground connection and ultimately through plumbing and drainage pipes. Some of these plumbing pipes were located in the space directly above our production area while the main drainage pipe was buried directly below; thus our production area was effectively inside of a huge coil. Our electrical contractor was embarrassed but confirmed our diagnosis, and the problem was quickly fixed.

Sometimes one has to think “outside of the box” to correctly perceive or understand a given problem.
 
Member
Joined 2004
Paid Member
As a first order measure a device under test may be placed in a metal enclosure and fed from as clean a power supply as possible. The output noise can then be compared to either a "normal" power line or one with a known quantity and type of noise.

I do have the ability to do this but my getting to doing more research on it is at least a year or more down the road.

ES

However the metal box could influence (reduce) the interference that the cable would conduct into it, or it could increase the currents with the larger capacitance to pass noise currents back to ground. This stuff is never easy to look at and the real network is very complex when external power is added to the mix.

If you look at what is required for FCC testing of conducted EMI (a one dimensional test) its pretty involved. For the radiated testing its much more involved. Meeting something like TEMPEST https://en.wikipedia.org/wiki/Tempest_(codename) would be an admirable goal for a really high quality audio product. Fortunately the specs are secret so its perfect audiophile fodder.
 
Status
Not open for further replies.