Often, yes. Or while waiting for coatings to dry.
That's also why my answers tend to be brief.
The lower frequency limit of a microphone is determined by the time constant of the static pressure equalization vent, which lies in the range 0.032 to 0.32 s, giving a lower limiting frequency (–3 dB) between 0.5 and 5Hz.
see:AIP Handbook of Condenser Microphones: Theory, Calibration and Measurements
see:AIP Handbook of Condenser Microphones: Theory, Calibration and Measurements
Richard Marsh, a very impressive website. I presume that your facility has been 'put to bed' much like Vendetta Research, but I don't know for sure.
You and I have been, along with Nelson Pass, and Charles Hansen, real competitors with each other, and even so, we can also be colleagues, when our love of the best hi fi possible is criticized or ridiculed.
I wish to point out that the CTC Blowtorch is an 'obsolete' but a worthy attempt to make the best preamp possible for the time. It is NOT its engineering, but its RAW COST in parts and assembly that made it 'obsolete'. We never made any real money from making them, just something to do and a modest payment for our time. The Blowtorch was virtually made by hand, with the best parts that we could find. Was it too much? In today's world YES.
You see, our customers, were generally very wealthy people and sales were made possible, when the world economy was much better. Many customer sales, I should bet, were made viable from company bonuses or a stock windfall, that gave the perspective customer a shot at THE BEST, no matter what the price.
It is interesting that the Japanese, when they were on the top of the economy, followed this pattern, but I don't hear as much from them, today, but they used to dominate the hi end audio, both in purchase of older, revered audio, like the Marantz tube products, and subsequently increased the 'cost of participation' in collecting audio components at almost any price.
Something that I have heard about, was the acquisition of Ferrari's, etc, by people newly funded by 'going public' or with other windfalls. Now, I suspect that we have too many Ferrari's for sale.
This is again WHY the CTC Blowtorch was 'put to bed' perhaps 7 years ago. Our 'profits' were nominal, and our expenses kept going up. We barely could buy the TKD pots, except at twice the price, the cost of the chassis virtually doubled over the 5 years or so that we had them made, even from the same machinist. It shows that MASS PRODUCTION can reduce costs, but custom fabrication always remains expensive, even after a run or two.
There are still companies who make 'world class' audio equipment that has very little competition for those who 'might' hear the difference, and Demian and I work for one. It is 'fun' to do the BEST job possible, but that does not mean that we will get rich or even a typical engineer's salary from doing so. It is just a 'labor of love' and that is enough for me, anyway.
You and I have been, along with Nelson Pass, and Charles Hansen, real competitors with each other, and even so, we can also be colleagues, when our love of the best hi fi possible is criticized or ridiculed.
I wish to point out that the CTC Blowtorch is an 'obsolete' but a worthy attempt to make the best preamp possible for the time. It is NOT its engineering, but its RAW COST in parts and assembly that made it 'obsolete'. We never made any real money from making them, just something to do and a modest payment for our time. The Blowtorch was virtually made by hand, with the best parts that we could find. Was it too much? In today's world YES.
You see, our customers, were generally very wealthy people and sales were made possible, when the world economy was much better. Many customer sales, I should bet, were made viable from company bonuses or a stock windfall, that gave the perspective customer a shot at THE BEST, no matter what the price.
It is interesting that the Japanese, when they were on the top of the economy, followed this pattern, but I don't hear as much from them, today, but they used to dominate the hi end audio, both in purchase of older, revered audio, like the Marantz tube products, and subsequently increased the 'cost of participation' in collecting audio components at almost any price.
Something that I have heard about, was the acquisition of Ferrari's, etc, by people newly funded by 'going public' or with other windfalls. Now, I suspect that we have too many Ferrari's for sale.
This is again WHY the CTC Blowtorch was 'put to bed' perhaps 7 years ago. Our 'profits' were nominal, and our expenses kept going up. We barely could buy the TKD pots, except at twice the price, the cost of the chassis virtually doubled over the 5 years or so that we had them made, even from the same machinist. It shows that MASS PRODUCTION can reduce costs, but custom fabrication always remains expensive, even after a run or two.
There are still companies who make 'world class' audio equipment that has very little competition for those who 'might' hear the difference, and Demian and I work for one. It is 'fun' to do the BEST job possible, but that does not mean that we will get rich or even a typical engineer's salary from doing so. It is just a 'labor of love' and that is enough for me, anyway.
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That's why I used a pressure guage, actually a differential one and sealed one side so the guage pressure is not known exactly but does not matter. It does go to DC.
Every time I travel in Europe I try to check out the audio magazines (the high end seems to be covered so much more there) and I see at least two or three or more "ultimate" phono stages, often the prices far outdo the CTC BT. Are there really that many fickle record collectors?
BTW Clark Gable's Deusenberg is on the block this week, estimate $10^7, Better tell your customers.
the rich are doing fine - corporate profits are high, CEO pay beating entire fed corporate tax bill at some $Billion companies
should still be a few whales out there looking for toys
a fun looking page on sound velocity: Speed of sound in air calculator and the temperature without barometric pressure - table air density of air calculation acoustic impedance air density sea level velocity ideal gas 20 degrees or 21 degrees Celsius C cold warm propagation velocity - se
should still be a few whales out there looking for toys
a fun looking page on sound velocity: Speed of sound in air calculator and the temperature without barometric pressure - table air density of air calculation acoustic impedance air density sea level velocity ideal gas 20 degrees or 21 degrees Celsius C cold warm propagation velocity - se
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Scott, do you have infrasonic observatory?
There is one in the nice place: Infrasound Laboratory
There is one in the nice place: Infrasound Laboratory
What surprises me about current "high-end" phono preamp offerings, in distinction I suspect to JC's past offerings, is how mediocre most are in noise performance, if we go by JA's measurements in Stereophile. Now he does not as yet attempt to terminate the inputs with loads representative of real cartridges, let alone do that and back out the parallel (i.e., "current") noise (he just measures the voltage noise). And no manufacturer that I know of provides parallel noise performance either. However (as you remarked somewhere), for MM cartridges one would want a JFET input, and among others the over-the-top Class A+ Boulder machine apparently still sticks to their spawn-of-Jensen 990 discrete opamps (Boulder does not reveal their phono performance).
Some of the preamps have actually been so bad that JA has complained, even when Fremer is going nuts over them.
The old National Semiconductor Audio Handbook is amusing about this issue of phono preamp noise performance. In the early part of the book, pushing one of their ICs for phono use, statements are made about noise performance. Then, in the back of the book, a detailed discussion and inventory of noise contributions basically refutes the claims made in the earlier part of the book!
Brad
$29,000 just for the phono and $36,000 for the rest! I hope there are no IC's in the signal path.
That reminds me of auditioning an all-JFET discrete buffer in the signal chain of a local high-end aficionado, the notion being that his and another's golden ears might to some extent sanction or reject material evidence of my design "philosophy" before I moved forward on additional designs for one of them. The system had a fancy CD transport and fancy DAC, the guy's latest favorite three-chassis tube line level preamp, my board, and on to a box which had equalization for the favorite loudspeakers of the day, and then some favorite power amp.
After expressing his concerns that my board might blow out the tweeters and thereby cost him thousands, we auditioned the system, and my board was adjudged undetectable, pretty much, to the guy's astonishment (as he hated solid state in general and was sure he could hear when it was present).
I didn't think it politic to point out that, aside from the electronics in the CD playback (accepted as a necessary evil, as repeated playing of the same LP would be out of the question), the loudspeaker EQ box was filled with IC opamps.
I guess that's why MBL sounds so "realistic." - omni-directional.
Discrete surround sound helps too.
Indeed very interesting stuff, but also stuff that has been researched ad infinitum. Seemingly unrelated issues like this 'filling in' of sound, expectation bias, changes in remembered events with circumstances, or, even more weird, phantom limb perceptions, all come back to one significant point: the brain is a prediction machine. Say a word and it completes the sentence, so to speak.
For 'us', there's a difference between, say, a 'real' chair in front of us and a chair remembered from yesterday. For the brain, it's all 'inside your head'. For the brain, there is no difference between reality and what is made up, remembered or imagined inside it.
But because we insist on this imaginary (pun intended) difference we get mad when someone suggests we imagined something. On the contrary, in a very real sense it's ALL imagined
jan
Hi Jan,
Well, not all imagined Jan. LEARNED. And there is a whole lot that goes on with our hearing that is understood that not many people understand or talk about.
For instance when a person has hearing loss it causes compensatory changes in the auditory pathways to try to compensate. Often when people first experience hearing loss they develop increased sensitivity to some sounds that are not loud (misophonia). It happened to my mom who found the turn signal on our car really bothersome for about a year, but eventually re-habituated to the sound and till it wasn't a problem.
The ears and whole sensory system work extremely well. And just because it can be fooled, doesn't mean the differences people say they can hear aren't real. Though I agree that often people, like my audiophile dad, attribute every difference they hear to the equipment which is a mistake.
John
It appears to me that the problem exists because the measured data goes against thier listening perceptions. Until that is resolved to thier satisfaction, explaining FFT et al is a waste of time on them. Perceptions Are a person's reality. So, in affect you are denying thier reality... which will never be accepted by many. we need a new strategy. IMO.
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