perhaps the next, no compromise step would be,
a "pressurized electrical system" ...
"pressurized electrical system" - Google Search
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John Curl's Blowtorch preamplifier part II
Replies: 2,200
Views: 1,247,432
I think I already asked: out of the total sales, how many BT preamps were sold to people living on a transmitter pole?
The balance was ripped off $3,000. They were not told they are paying for such an expensive (and useless for them) feature (which, BTW, has a questionable efficiency, this was already discussed long time ago).
But otherwise I agree people love heavy equipment. It makes them feel secure and confident
A simple and well known marketing fact.
Too noisy, Tomtt.
However, a completely independent research effort by the National Institute of Standards and Technology has published a paper:
'SUPERIMPOSING LOW PHASE NOISE, LOW-DRIFT INSTRUMENTATION TECHNIQUES ON RF DESIGN' by C.M. FELTON
Please everyone, you will see that it closely parallels the CTC Blowtorch and Vendetta Research approach to power supply regulation. Someone here posted a link, so it should be available.
However, a completely independent research effort by the National Institute of Standards and Technology has published a paper:
'SUPERIMPOSING LOW PHASE NOISE, LOW-DRIFT INSTRUMENTATION TECHNIQUES ON RF DESIGN' by C.M. FELTON
Please everyone, you will see that it closely parallels the CTC Blowtorch and Vendetta Research approach to power supply regulation. Someone here posted a link, so it should be available.
Hi simon7000,
Interesting, and all true.
I once knew another fellow who worked at a couple AM transmitting sites, and another who surveyed transmitting sites. He also certified the ground resistance of the installations. We had some interesting conversations.
Hi John,
I was referring to RFI when I commented about AL foil. It was effective in those cases. Understand that this was a method used to prove to customers that the problem was environmental and not with the equipment. Doing warranty service can lead a person down some funny paths.
As for the weight of the chassis, it is both a selling feature and suggests value in the mind of a consumer. Like seat belts, how many people will actually need the preemptive measures of a heavy chassis? I'll guess that seat belts are used by a higher percentage these days, but the heavy construction of the case is sure nice to have - even when not required.
-Chris
Interesting, and all true.
I once knew another fellow who worked at a couple AM transmitting sites, and another who surveyed transmitting sites. He also certified the ground resistance of the installations. We had some interesting conversations.
Hi John,
I was referring to RFI when I commented about AL foil. It was effective in those cases. Understand that this was a method used to prove to customers that the problem was environmental and not with the equipment. Doing warranty service can lead a person down some funny paths.
As for the weight of the chassis, it is both a selling feature and suggests value in the mind of a consumer. Like seat belts, how many people will actually need the preemptive measures of a heavy chassis? I'll guess that seat belts are used by a higher percentage these days, but the heavy construction of the case is sure nice to have - even when not required.
-Chris
Chris,
as already explained many times, the thick Al case shields by eddy currents effect and is pretty effective even for low frequencies, not only RF. Al skin depth is about 11mm at 50Hz.
as already explained many times, the thick Al case shields by eddy currents effect and is pretty effective even for low frequencies, not only RF. Al skin depth is about 11mm at 50Hz.
You may have 'static' magnetic shielding by ferromagnetic material, or shielding by non-magnetic, conductive material, that shields by eddy currents (skin effect)
Skin effect - Wikipedia, the free encyclopedia
Skin effect does not shield against DC magnetic field.
Skin effect - Wikipedia, the free encyclopedia
Skin effect does not shield against DC magnetic field.
Hi Pavel,
Thanks, but I think you misunderstood what the point of my post was. You've assumed it was about 180 ° from what my intention was.
In no way was I attacking the fact that the case was thick. Nor was I attacking the reasons for making the case thicker.
I found out that AL was good with eddy currents through direct experience. That's how a Thorens TD-124 controls it's speed. A magnet with a partial AL disc between that and the platter. A really nifty system if you ask me. You vary the amount of aluminum between the platter and the magnet.
I guess the magnet represents a frequency of zero, and the platter imperfections would represent close to 1.8 Hz at 33.3 rpm. 🙂 In any event, aluminum does support eddy currents, and these can even be used in a mechanical way. It's not just for electromagnetic shielding anymore! 😉
-Chris
Thanks, but I think you misunderstood what the point of my post was. You've assumed it was about 180 ° from what my intention was.
In no way was I attacking the fact that the case was thick. Nor was I attacking the reasons for making the case thicker.
I found out that AL was good with eddy currents through direct experience. That's how a Thorens TD-124 controls it's speed. A magnet with a partial AL disc between that and the platter. A really nifty system if you ask me. You vary the amount of aluminum between the platter and the magnet.
I guess the magnet represents a frequency of zero, and the platter imperfections would represent close to 1.8 Hz at 33.3 rpm. 🙂 In any event, aluminum does support eddy currents, and these can even be used in a mechanical way. It's not just for electromagnetic shielding anymore! 😉
-Chris
Hi Chris,
Eddy currents in Al have been used for many years for damping motion without contact that could alter results. Laboratory scales are a good example.
Eddy currents in Al have been used for many years for damping motion without contact that could alter results. Laboratory scales are a good example.
So the value I posted (11mm at 50Hz) computed by my head without any calculator is not that bad, is not it? 🙂
Wondering how the rest of the high end audio designers (I can think of a few successful models) ever thought they will get along without a 1/2 inch thick case.
The next step for a no compromise amp would be to build the case out of solid silver. This will certainly help and the amp will have a open, silverish sound
The next step for a no compromise amp would be to build the case out of solid silver. This will certainly help and the amp will have a open, silverish sound
Wondering how the rest of the high end audio designers (I can think of a few successful models) ever thought they will get along without a 1/2 inch thick case.
The next step for a no compromise amp would be to build the case out of solid silver. This will certainly help and the amp will have a open, silverish sound
Yes but John is talking about a $40K plus piece of gear here. It has to be an all out assault and no expense spared on anything.
Have you changed your mind lately? You now think the price tag is a guarantee for quality?
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