That is why the CTC Blowtorch was so expensive to make. We went for the BEST that we knew that was available. It cost us plenty, but we tried to keep the ultimate price reasonable by selling DIRECT, no dealers in the USA. However, offshore importers, like the Japanese could mark up the design to whatever they thought the market would bear. They went with with 5,000,000 yen, or about 5 times the price we sold it to them at. That's a real problem with offshore importers, they may have the customers, but the customers pay MUCH more than if they bought it in the USA.
I am struggling now with a problem that would have seemed to have an obvious solution, perhaps 20 years ago, but is amazingly difficult to solve.
For ULTIMATE MC input loading, I thought that a 10 turn, wirewound pot would be the ultimate in linearity and sophistication. This could be tracked by an added pot that could lead to a read-out so the customer would know what the loading resistance was, and it could be controlled by remote control. This would give the listener a chance to 'dial in' the actual load resistance from the listener's position, an ideal way do doing it. So far as we can estimate, it will cost us a few thousand dollars OEM to do this right. What a headache!
I am struggling now with a problem that would have seemed to have an obvious solution, perhaps 20 years ago, but is amazingly difficult to solve.
For ULTIMATE MC input loading, I thought that a 10 turn, wirewound pot would be the ultimate in linearity and sophistication. This could be tracked by an added pot that could lead to a read-out so the customer would know what the loading resistance was, and it could be controlled by remote control. This would give the listener a chance to 'dial in' the actual load resistance from the listener's position, an ideal way do doing it. So far as we can estimate, it will cost us a few thousand dollars OEM to do this right. What a headache!
Why is that so expensive John? I can understand that you want a very good wirewound, but the 2nd pot can be a linear pot running on a DC voltage, with the wiper DC into a PIC's A/D converter and into a standard A/N display. You can put a cal or translation table in the PIC.
The PIC can also do reception and decoding of the remote signal and drive a small DC motor for the wirewound.
That part of the system should not set you back more than perhaps $70 or $80 tops.
jan
The PIC can also do reception and decoding of the remote signal and drive a small DC motor for the wirewound.
That part of the system should not set you back more than perhaps $70 or $80 tops.
jan
The types of FR4 available today are totaly different from what they were years ago. With the advent of lead free soldering and the increase in process temperatures, plus the ever increasing high speeds of digiatl signals, the ever decreasing supply voltages etc you cannot reference designs and materials from 25 years ago today. There has also been many changes in the glass weave in FR4 from the horrible 1080 of years ago to todays laminates designed for high temps (Tg 170) and high speed designs.
If you want to achieve he best possible design be it digital or analogue you are better of looking at the layout rather than base materials, we use FR4s for most of the designs we do, and probably 95% of all he ones we do use FR4, these are designs for a whole host of curtomers many of them medical, areospace and military designs. Using exotic materials adds other problems and cost for no benefit.
If you want to achieve he best possible design be it digital or analogue you are better of looking at the layout rather than base materials, we use FR4s for most of the designs we do, and probably 95% of all he ones we do use FR4, these are designs for a whole host of curtomers many of them medical, areospace and military designs. Using exotic materials adds other problems and cost for no benefit.
Why do you assume that, I cant understand some replies, or the paranoia in the replies!
i am just giving some advice like many others do on this forum. PCB design just happens to be my area of expertease, and I am pretty much an expert in the design and assembly of PCB's and most aspects sourounding them.It does get my back up though when you get replies like yours Bcarso, I was not implying anything, so why reply in such a way, take a chill pill as my Kids would say
i am just giving some advice like many others do on this forum. PCB design just happens to be my area of expertease, and I am pretty much an expert in the design and assembly of PCB's and most aspects sourounding them.It does get my back up though when you get replies like yours Bcarso, I was not implying anything, so why reply in such a way, take a chill pill as my Kids would say
few nodes in a amp are high enough impedance for the pcb dielectric nonideal behavior to have any effect
those few can be often be guarded - the same layout used for pcb leakage current bootstrapping at high Z also provides dielectric C bootstrapping
for low production exotics or hobby amps press in teflon standoffs or air wiring sensitive nodes can work too where a few hand soldering operations doesn't blow the budget
another modern option is multilayer with the teflon only on the outer layer - with smt you may be able to keep sensitive nodes entirely on the surface of the "good" dielectric
those few can be often be guarded - the same layout used for pcb leakage current bootstrapping at high Z also provides dielectric C bootstrapping
for low production exotics or hobby amps press in teflon standoffs or air wiring sensitive nodes can work too where a few hand soldering operations doesn't blow the budget
another modern option is multilayer with the teflon only on the outer layer - with smt you may be able to keep sensitive nodes entirely on the surface of the "good" dielectric
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And you are saying I am touchy!Why do you assume that, I cant understand some replies, or the paranoia in the replies!
i am just giving some advice like many others do on this forum. PCB design just happens to be my area of expertease, and I am pretty much an expert in the design and assembly of PCB's and most aspects sourounding them.It does get my back up though when you get replies like yours Bcarso, I was not implying anything, so why reply in such a way, take a chill pill as my Kids would say
Look, you jump in here after Wayne asks about board material, and say that we shouldn't worry about that. And that we should worry about layout, as if Wayne and John and the rest do not. And each time you return and reiterate, you mention layout. It seems a not-unreasonable assumption to suppose you are suggesting we don't care about layout.
And where is this "paranoia"? This thread has been remarkably even-tempered of late, as things go.
Your insights into the evolution of PCB materials are welcome, and I'm confident that your own are of sufficient quality. I must however remind you that this is a global forum, and the opportunities for shoddy materials to slip into the manufacturing of equipment are abundant. I speak from bitter experience, in one case where a bad batch of ceramics used in 100nF capacitors practically killed someone, and cost the manufacturer about 1.5 million dollars in rework costs and momentarily shut down the shipping of computers by a major.
It is not unreasonable to suppose that, even in this day and age, circuit board materials could be of poor quality and still be shipped by a less-than-scrupulous vendor.
I would like to thank everybody for input on board materials. FR4 or 406 is my standard for usual work with 406 for power supplies. I have noticed that our production boards sound better than the prototypes do. Two different companies and slight physical differences in the boardslooks. Production boards are in Sunnyvale and they do good work and are offering me input on materials.
I haven't worked with Teflon in 25 years and there are so many choices today.
It may just be guilding the lily but I trust JC and his audio opinions. A bad layout as Marce pointed out can kill the whole thing I suppose that is why I like to do my own. Easier today with PCAD and Altium instead of mylar and tape. No wonder I have grey hair.
Two different companies and slight physical differences in the boardslooks. Production boards are in Sunnyvale and they do good work and are offering me input on materials.I haven't worked with Teflon in 25 years and there are so many choices today.
It may just be guilding the lily but I trust JC and his audio opinions. A bad layout as Marce pointed out can kill the whole thing I suppose that is why I like to do my own. Easier today with PCAD and Altium instead of mylar and tape. No wonder I have grey hair.
Here's the nice tutorial:
Tom Jerse and Mark Terrien, "A Designer's Guide To Shielding"
http://www.hparchive.com/seminar_notes/a-104.pdf
Apologies if it has been posted here before.
Tom Jerse and Mark Terrien, "A Designer's Guide To Shielding"
http://www.hparchive.com/seminar_notes/a-104.pdf
Apologies if it has been posted here before.
Bsarso, ot touchy grumpy maybe, but it was not I who insinuated hat people dont care about layout, its you who jumped up and down.
As to jump in, its a public, Im allowed to jump in!
There are many here (many) who are new to electronics and PCB layout, what I was saying was that you dont have to worry about exotic PCB materials for audio and the best way of getting good results is learning layout properly, not concentrating on esoteric materials.
As to bad materials, yes you can get low grade FR4, but not if you go to a reptuble PCB manufacturer. There was a lot of 130 deg C TG stuff in the far east when lead free came in, which whilst not bad was realy unsuitable for lead free processing, a large amount of this got used up for consumer goods for a numbr of years ou could get silly prices on basic 2 and 4 layer boards from the far east.
I doo find your attack rather upsetting, and paranoid in nature. As to layouts on this site some are very good, the majority are god, and a few are mediocre. I was just airing a cooment and do not justify your attack, it was advice similar to the advice that others post, for the newer people to this sort of thing.
Its the same with EMC, good EMC design starts with the layout, get that right and your on to a winner.
Sorry to disapoint you but ood layout is the most critical aspect of PCB design,for EMC, thermal, signal integrity and a circuit that works. As to my designs, they have to be as near perfect as possible, as more often than not they are in life critical systems, something that is always is a the back of your mind, as failure could result in someones death. But I have also been lucky in a long and varied career to have worked with lots of interesting and clever people, from whom I have learned a lot, and as for myself have studied all aspecpts of PCB design, manufacture and assembly for over 25 years.
So I would ask you to desist with you silly allegations and real your neck in.
Again a bad layout with the best materials in the world is not gonna work is it!
As to jump in, its a public, Im allowed to jump in!
There are many here (many) who are new to electronics and PCB layout, what I was saying was that you dont have to worry about exotic PCB materials for audio and the best way of getting good results is learning layout properly, not concentrating on esoteric materials.
As to bad materials, yes you can get low grade FR4, but not if you go to a reptuble PCB manufacturer. There was a lot of 130 deg C TG stuff in the far east when lead free came in, which whilst not bad was realy unsuitable for lead free processing, a large amount of this got used up for consumer goods for a numbr of years ou could get silly prices on basic 2 and 4 layer boards from the far east.
I doo find your attack rather upsetting, and paranoid in nature. As to layouts on this site some are very good, the majority are god, and a few are mediocre. I was just airing a cooment and do not justify your attack, it was advice similar to the advice that others post, for the newer people to this sort of thing.
Its the same with EMC, good EMC design starts with the layout, get that right and your on to a winner.
Sorry to disapoint you but ood layout is the most critical aspect of PCB design,for EMC, thermal, signal integrity and a circuit that works. As to my designs, they have to be as near perfect as possible, as more often than not they are in life critical systems, something that is always is a the back of your mind, as failure could result in someones death. But I have also been lucky in a long and varied career to have worked with lots of interesting and clever people, from whom I have learned a lot, and as for myself have studied all aspecpts of PCB design, manufacture and assembly for over 25 years.
So I would ask you to desist with you silly allegations and real your neck in.
Again a bad layout with the best materials in the world is not gonna work is it!
I've never seen it before, thank you very much.
I note several important concepts for audio, all on page 6.
1. Near field, far field
2. 377 ohms
3. The E vs H impedance nearfield.
These concepts are significant when it comes to audio, low level, low impedance stuff. EMC theory expounds more along that line as well.
Kept my copy for reference...thanks again.
jn
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