I just spoke to Jack a few minutes ago. He is as real as anybody that I know, and his devices are very useful as sonic improvers.
Wire inductance: a measurement
Just now I measured the inductance of a piece of 22 AWG solid core hookup wire. The segment I measured was 13 ft 0 inches long (396 cm). I laid it out on my benchtop (ABS plastic) in a rough circle, then taped it in place for measurements.
I measured the inductance three times with three different instruments, Figures 1-4 below. (Click on the images to remove compression distortion) The first two were LCR meters; their results were 5.80 uH and 5.88 uH respectively. The third was an LC oscillator (Fig 3), resonating the unknown inductance with a known fixed capacitor whose value is 100 nanofarads. Resonant frequency was 208 kHz (Fig 4), which plugs into the LC resonator equation, yielding inductance L = 5.84 microhenries.
As Scott Wurcer remarked, not exactly backbreaking effort.
Did I measure the inductance of a second piece of hookup wire, to find out whether
No I did not. I didn't want to ruin anybody's joy of discovery, in case other diyAudio members here might be preparing to perform such measurements. Please proceed! Accumulate knowledge and have fun!
Just now I measured the inductance of a piece of 22 AWG solid core hookup wire. The segment I measured was 13 ft 0 inches long (396 cm). I laid it out on my benchtop (ABS plastic) in a rough circle, then taped it in place for measurements.
I measured the inductance three times with three different instruments, Figures 1-4 below. (Click on the images to remove compression distortion) The first two were LCR meters; their results were 5.80 uH and 5.88 uH respectively. The third was an LC oscillator (Fig 3), resonating the unknown inductance with a known fixed capacitor whose value is 100 nanofarads. Resonant frequency was 208 kHz (Fig 4), which plugs into the LC resonator equation, yielding inductance L = 5.84 microhenries.
As Scott Wurcer remarked, not exactly backbreaking effort.
Did I measure the inductance of a second piece of hookup wire, to find out whether
(inductanceX / inductanceY) == (LengthX / LengthY)
?? No I did not. I didn't want to ruin anybody's joy of discovery, in case other diyAudio members here might be preparing to perform such measurements. Please proceed! Accumulate knowledge and have fun!
Attachments
I measure similar.... 6.6 uH. @ 1KHz. But my wire was not solid... 13', 22 awg, stranded...... changes a small amount with freq.
THx-RNMarsh
THx-RNMarsh
I just saw this today which gets to what I was asking about.
https://www.google.com/patents/US5099518
20 years ago, I developed different solution that stays with copper -- and idea was sold to a company.
-RM
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DPH,
the board sans external power supply will be internal to the enclosure. Not so sure that should be a serious issue as long as no components are microphonic in use. Time will tell if a conformal coating or isolation of the board becomes necessary. First I need a board design to test.
Jan,
The PCB has a good deal of room inside the enclosure from front to back but the way the heatsink is mounted on the rear of the enclosure the surface area is only about 4 1/4" wide by about 15" height with vertically running fins. So there is some room to play with board layout and perhaps it should really be more than one board, I would defer to the experts on that aspect of the design.
the board sans external power supply will be internal to the enclosure. Not so sure that should be a serious issue as long as no components are microphonic in use. Time will tell if a conformal coating or isolation of the board becomes necessary. First I need a board design to test.
Jan,
The PCB has a good deal of room inside the enclosure from front to back but the way the heatsink is mounted on the rear of the enclosure the surface area is only about 4 1/4" wide by about 15" height with vertically running fins. So there is some room to play with board layout and perhaps it should really be more than one board, I would defer to the experts on that aspect of the design.
and measured 3.5 uh with 6.50 ft length. What are we doing this for?
http://www.qsl.net/zl1an/Downloads/Inductance_Problem.pdf
-RM
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🙁 . I didn't know that. I did PM him about a month ago and no response. How much bad luck can a guy have in 12 months.
In other new Audible Illusions is launching a new phono preamp. Interestingly they have told journos it's "
based upon the original Modulus' John Curl designed phono section".
I do hope JC was asked to tweak the design rather than them just leveraging his name to justify an 8k price tag!
based upon the original Modulus' John Curl designed phono section".
I do hope JC was asked to tweak the design rather than them just leveraging his name to justify an 8k price tag!
I don't remember VAX. Was it with huge curved black shiny like grand piano speakers that had uneven frequency response in all directions?
What I liked the most, humble white horns by a senior German guy, demonstrated by Mike, Audio Federation.
The next day I tried my new amp prototype with Legacy Focus speakers in San Jose, and was very impressed. I am sure if I tried my new amp with that white horns, it would be a killing combination.
It is a 42W per channel SE amp I am proud of.
Attachments
2 pentodes, nested feedback loops, MOSFET regulators for G1, G2, G3, for driver, B+ shunted by film caps. MOSFET follower loaded on CCS driving G1, Soviet military 125W output tube, US made TV video frame grid input tube. 150W SMPS for filaments, that's why it is so small and light enough by be carried by a single man.
20 Hz - 50KHz without visible roll off.
Here is the picture, symmetric soft clipping on 8 Ohm (1:10 probe)
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Good idea.
That's probably why you haven't noticed that you bring that here. I'm as type B about work as can be. I always let my direct reports make their families and personal health first and covered for them even if it meant not submitting sick time. We still managed about 900M in product shipped and helped drive the stock price through the roof.
As for checking egos please do, you're the pot and I don't see too many kettles here.
That reminds me. The variability you measured on film caps is usually from the end termination method and materials. Did you ever take the caps apart and see how the lead was attached? On some of the cheaper ones, you would be amazed.
Also, the values tested were too small for anything except bypasses. How do larger values compare? And, how do they do when you run some significant current thru them... as in speaker cross-over use. [put some volt and amps thru bi-polar types found in speaker cross-overs for laughs]
And still no tests using asymmetrical waveforms.
THx-RNMarsh
Also, the values tested were too small for anything except bypasses. How do larger values compare? And, how do they do when you run some significant current thru them... as in speaker cross-over use. [put some volt and amps thru bi-polar types found in speaker cross-overs for laughs]
And still no tests using asymmetrical waveforms.
THx-RNMarsh
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You always have unique designs. Nice looking build quality also. What are the distortion numbers?
I notice the use of cable lifters? What do they do for system sound?
THx-Richard
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rant over. you must be type A when driving many people with all sorts of personalities and backgrounds on a strict time-line and budget. Many who never worked together before. Brought together for a finite time. Not the same as factory/production work re product you know how to make and sure will work. A lot of construction... technical facilities from the ground up. Biggest problem as a group was construction people... plant engineering.... if you weren't checking their work freq, some bad **** would happen... and it did a few times, got past me when I looked away. The kind of bone head things which people loose their jobs over. But electronic engineering had their screw-ups too which were career ending. Laid back never worked there... why I did well in that type of unique work. No two physics projects were ever the same in any way and each was unique. Plenty of challenges. Lots of creative problem solving for all involved while the clock was ticking. You better be done on time and budget... There was no more money. If you had to ask for more money from congress, management careers would end. Hi pressure. I loved it, though. In the end, it was the great people I missed the most.
THx-RNMarsh - retired.
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Those would be the same type-As at NASA that led to the shuttle disasters? Yeah projects really need guys like that. In the best case they type As screw everything up then, by making everyone work 80 hours a week recover the (avoidable) screw up and emerge as some hero to the C suite.
Luckily most of my projects have not had those sort running them. But the ones I did went wrong as expected. YMMV.
Startups need sociopaths to get running. For the rest of us calm and respect are far more efficient.
Luckily most of my projects have not had those sort running them. But the ones I did went wrong as expected. YMMV.
Startups need sociopaths to get running. For the rest of us calm and respect are far more efficient.
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