Like the folks that daisy-chain 2 100' extension cords for their electric lawn mower.
No, 90V in outlets near the stage after 7pm.
Batteries would help in such situation.
Well,these indeed are interesting observations.
The question is why? Can we come up with a rational explanation, and, can we measure it, which might point us in the right direction.
I don't follow the split vs. single discussion. Perhaps a model may make this more obvious since we seem to have gone around a loop here.
Split primary passes more noise than a single primary- how? Is it intrinsic or just due to the physical implementation?
How does the split secondary cancel the noise?
Are you talking differential or common mode noise?
38 pF from AC primary to DC ground on the secondary is not much. Maybe measuring the response of the transformer is the next step?
Split primary passes more noise than a single primary- how? Is it intrinsic or just due to the physical implementation?
How does the split secondary cancel the noise?
Are you talking differential or common mode noise?
38 pF from AC primary to DC ground on the secondary is not much. Maybe measuring the response of the transformer is the next step?
May be after trying a bag of magic crystals on power cord.
Dielectric resonators tuned to each critical frequency in the ISM band. About $1K worth of tuned traps. (I also sell used bridges.)
Let's take a break and relax a bit, it helps to solve problems.
Russian ROBOT GUITAR. Tico-Tico - YouTube!
Russian ROBOT GUITAR. Tico-Tico - YouTube!
A dual primary has a bit less inductance. When you have a dual secondary the desired AC coupling is of course magnetic. You can rectify this and get useful DC. There is coupling that peaks around 100-200 KHz. in the transformers I measured (Ca. 1972!) This is mostly capacitive. If you use a full bridge on each secondary you can reverse one secondary winding so any coupled noise is cancelled.
When they wind dual primaries even with both wires wound at the same time there is more noise coupling to the secondary. If the primary windings are wound one on top of the other you really lose noise balance and more noise is coupled.
As mentioned my measurements on this are old and may not apply to newer transformer design methods.
When I build a circuit from the schematic , I find it natural to physically locate the components (form) in line with the schematic (function). Apart from the intuitive reason for doing this and the practical outcome of easy debugging, I tend to come to the thinking that such an approach may have a far more important aspect.
It was the writings of Ivor Cat that introduced me to the idea. Next it was Heaviside making clear that the propagation of electromagnetic waves is accomplished along wires through the dielectric surrounding them, vs. the electrical conductors serve as the boundary guides for the electromagnetic energy to propagate to a certain direction through a dielectric medium.
Now, think of an electronic circuit, say a filter, a preamplifier ect as a physical and functional part of a transmission chain, positioned between an input and an output set of electrical conductors.
In the schematic of this electronic circuit, the “function” has an input, an output, the “signal” and the “return” lines plus some branches in-between. If the physical implementation (form) respects in 3D the outlay of the schematic, the confines of the “electromagnetic waves flow” from input to output are thus defined. The enclosed volume is the dielectric (air) and all components placed in it (and outside of it but close enough) affect and are affected by the propagating em waves.
George
I've never done layout but only worked with others. And usually the best results, or at least the ones requiring the least scrutiny and intervention, have indeed come from those whose layouts tended to conform to the affine geometry of the schematic.
One intriguing thing to me: in ICs and PCBs, until recently and with rare exceptions (Jonathan Carr's preamp comes to mind) we are all tending to think as if we're confined to a plane.
As this thread isn't nearly long enough
, perhaps it's time to branch off into explorations of practices that have become a little hidebound, however successful.
Brad
One intriguing thing to me: in ICs and PCBs, until recently and with rare exceptions (Jonathan Carr's preamp comes to mind) we are all tending to think as if we're confined to a plane.
As this thread isn't nearly long enough
, perhaps it's time to branch off into explorations of practices that have become a little hidebound, however successful. Brad
Let's take a break and relax a bit, it helps to solve problems.
Russian ROBOT GUITAR. Tico-Tico - YouTube!
I love it. Here's one you may like, and all analog, too:
Sweet Georgia Brown & traktor (edited version) - YouTube
Thanks,
Chris
Thanks Chris;
one more: The Tractor Blues Jam..!! - National Duolian & Victor the tractor!! - YouTube
I've never done layout but only worked with others. And usually the best results, or at least the ones requiring the least scrutiny and intervention, have indeed come from those whose layouts tended to conform to the affine geometry of the schematic.
One intriguing thing to me: in ICs and PCBs, until recently and with rare exceptions (Jonathan Carr's preamp comes to mind) we are all tending to think as if we're confined to a plane.
As this thread isn't nearly long enough
Brad
Brad
3D nested constructions was a common place among radio amateurs some decades ago when they were diying their equipment and tools. Did they knew better?
Also some audio diy constructions are still constructed this way.
Ics:I am intrigued myself and I would like to ask Scott if during implementation of circuits within Ics they consider “3D effective space” (something like electromagnetic plain wave approach I wrote before)
George
Circuit layout is an 'ART' all to itself. I have worked both with good and bad layout people as business partners, and hired a number of marginal people, in between.
IF I am in charge of virtually all the circuit needs and functions, it is easier to get a good layout person to do an intuitive, elegant layout.
However, some people are LOUSY layout people, no matter what their experience.
In 1970, Alembic hired a guy, who got very famous in later years, and one of his first jobs was to build the prototype on vector-board, of one of my complementary differential input power amps, something like the JC-3, except with all bipolar transistors. He did such a LOUSY job, and though he made a working prototype, it was so vastly different physically, from the schematic, that I could barely find my way around the circuit that I had designed. I would have fired him on the spot, if he had been my employee.
10 years later, I had a business partner, who was a great 'fabricator' but who thought that he could do great circuit board layout, as well. He made the circuit board for the SOTA head amp. This layout was so bad, that we had noticeable hum pickup, even though we ran on batteries, and the circuit was mearly a simplified Levinson JC-1 with only a single pair of bipolar transistors used, rather than 4 pairs per channel. Later, he tried to do a layout for UCB and it was rejected as being next to useless. YET, I could never tell him that he was a lousy layout guy, he just would NOT hear of it.
Another few years goes by, and Dennesen hired another 'designer' do design the circuit board for the JC-80. It was essentially awful, yet we lived with it for years. The Japanese were so unhappy with the layout, that they did their own boards for use for a JC-80's to be sold in Japan. For this, we got preamp of the year, at one point.
Then, about 10 years later, I had a turn with the layout people in Taiwan for Parasound. I threatened to quit, if they did not get someone to clean up the layouts. It was embarrassing, as if they had hired a 'cousin' to do the work, rather than a professional.
Talent, unfortunately is only one part of the problem. The other part is how much added garbage that does nothing for the audio, except to add an optional accessory to the mix, the kind of the options that mid fi likes to add. This creates forced compromises in the effort that even the best layout person can make.
That is why the CTC Blowtorch is so 'elegant' in its circuit path, NO ACCESSORIES! '-)
Kind of like a race car.
IF I am in charge of virtually all the circuit needs and functions, it is easier to get a good layout person to do an intuitive, elegant layout.
However, some people are LOUSY layout people, no matter what their experience.
In 1970, Alembic hired a guy, who got very famous in later years, and one of his first jobs was to build the prototype on vector-board, of one of my complementary differential input power amps, something like the JC-3, except with all bipolar transistors. He did such a LOUSY job, and though he made a working prototype, it was so vastly different physically, from the schematic, that I could barely find my way around the circuit that I had designed. I would have fired him on the spot, if he had been my employee.
10 years later, I had a business partner, who was a great 'fabricator' but who thought that he could do great circuit board layout, as well. He made the circuit board for the SOTA head amp. This layout was so bad, that we had noticeable hum pickup, even though we ran on batteries, and the circuit was mearly a simplified Levinson JC-1 with only a single pair of bipolar transistors used, rather than 4 pairs per channel. Later, he tried to do a layout for UCB and it was rejected as being next to useless. YET, I could never tell him that he was a lousy layout guy, he just would NOT hear of it.
Another few years goes by, and Dennesen hired another 'designer' do design the circuit board for the JC-80. It was essentially awful, yet we lived with it for years. The Japanese were so unhappy with the layout, that they did their own boards for use for a JC-80's to be sold in Japan. For this, we got preamp of the year, at one point.
Then, about 10 years later, I had a turn with the layout people in Taiwan for Parasound. I threatened to quit, if they did not get someone to clean up the layouts. It was embarrassing, as if they had hired a 'cousin' to do the work, rather than a professional.
Talent, unfortunately is only one part of the problem. The other part is how much added garbage that does nothing for the audio, except to add an optional accessory to the mix, the kind of the options that mid fi likes to add. This creates forced compromises in the effort that even the best layout person can make.
That is why the CTC Blowtorch is so 'elegant' in its circuit path, NO ACCESSORIES! '-)
Kind of like a race car.
One of the first personal computers was the PERQ. It for a short time was the darling of the graphics and printing industry due to it's advanced capacity and graphical software. (They stole it from Xerox first!)
Well for the latest and greatest version they had a summer intern do the PC layout. Surprise it didn't work, it had lots of problems and they lost delivery schedule and the money for the run of boards. That is why you probably never heard of them.
Well for the latest and greatest version they had a summer intern do the PC layout. Surprise it didn't work, it had lots of problems and they lost delivery schedule and the money for the run of boards. That is why you probably never heard of them.
"throw it over the wall" artificial compartmentalization can ruin good circuits with poor layout - the layout is part of the circuit
I always sit with the layout guy for the 1st pass parts placement from the "rats nest", and talk with him while adding notes to the schematic about which nodes are sensitive, ends of parts that go together, signals that are noisy, which have to be paired
have often had things reworked after he comes back with his 1st pass – cheaper than extra board spins – simply don’t approve bad layouts – don’t work for people who won’t let you control it
at one job I was asked to fix a product that a board spin for new packaging/form factor had ruined - a input trace had been routed under a RM core inductor tuning/filtering the test source oscillator - and then amplified by 1000x – somehow it didn’t meet the original product’s specs anymore
the test engineer hunted me down at lunch after the layout I supervised proto came back wanting to know how I improved the noise performance >4x over the original "good" version of the product before the disastrous layout – apparently they only expected it to match the previous “good” implementation’s spec
I always sit with the layout guy for the 1st pass parts placement from the "rats nest", and talk with him while adding notes to the schematic about which nodes are sensitive, ends of parts that go together, signals that are noisy, which have to be paired
have often had things reworked after he comes back with his 1st pass – cheaper than extra board spins – simply don’t approve bad layouts – don’t work for people who won’t let you control it
at one job I was asked to fix a product that a board spin for new packaging/form factor had ruined - a input trace had been routed under a RM core inductor tuning/filtering the test source oscillator - and then amplified by 1000x – somehow it didn’t meet the original product’s specs anymore
the test engineer hunted me down at lunch after the layout I supervised proto came back wanting to know how I improved the noise performance >4x over the original "good" version of the product before the disastrous layout – apparently they only expected it to match the previous “good” implementation’s spec
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