Calibration has its bad points too.
I once had a calibration go wrong.
It turned out the factory lab was miscalibrated by 0.1dB!
The Sulphur trap is because of the silver contacts on the switches, they will corrode rapidly in the presence of suplhur.
Wrinkle
John,
Since we weren't a tier one manufacturer and this was not a new program there were no cost over runs, it wasn't an F35 where it was cost plus. I did have to solve a problem with a test fixture for a Lockheed program with a series of tools and precision spaced holes on a contoured part. Before me they would remove the bushing in the tool every time they had to re-certify the test fixture. I looked at how they were locating the bushing and using an alignment pin that had the same tolerance as the final part. I ordered some precision ground pins with a +/- tolerance ten times closer and the problem was solved. Sometimes it is just the way you look at the problem and come up with the solution.
I bet that a few of us here could do a design for you and it would make your products stand out from the crowd on the industrial design side. I am not going to advise you about your internal electronics, I do believe you know what you are doing with that portion of the product.
I do lots of work at home on my computer now, my cad programs don't care where I am doing the work, it is all relative. I'm also online with a composites group and have been asked to contribute to a major university project with the automotive industry and the light weighting of the next generation of cars and trucks. No money in it but it will help our American industry to stay here in America and compete and meet upcoming CAFE standards for fuel mileage. I could get some royalty payment if something I contribute is used as we will retain the IP rights to what we contribute. It is actually fun, something I know about just as here some of you are pro's at what you do and contribute for the rest of us.
Since we weren't a tier one manufacturer and this was not a new program there were no cost over runs, it wasn't an F35 where it was cost plus. I did have to solve a problem with a test fixture for a Lockheed program with a series of tools and precision spaced holes on a contoured part. Before me they would remove the bushing in the tool every time they had to re-certify the test fixture. I looked at how they were locating the bushing and using an alignment pin that had the same tolerance as the final part. I ordered some precision ground pins with a +/- tolerance ten times closer and the problem was solved. Sometimes it is just the way you look at the problem and come up with the solution.
I bet that a few of us here could do a design for you and it would make your products stand out from the crowd on the industrial design side. I am not going to advise you about your internal electronics, I do believe you know what you are doing with that portion of the product.
I do lots of work at home on my computer now, my cad programs don't care where I am doing the work, it is all relative. I'm also online with a composites group and have been asked to contribute to a major university project with the automotive industry and the light weighting of the next generation of cars and trucks. No money in it but it will help our American industry to stay here in America and compete and meet upcoming CAFE standards for fuel mileage. I could get some royalty payment if something I contribute is used as we will retain the IP rights to what we contribute. It is actually fun, something I know about just as here some of you are pro's at what you do and contribute for the rest of us.
It's also easy to casually dismiss experts because you are embarrassed at your lack of understanding. You are guilty of this.
All it takes is one machinist looking at all the prints, understanding trivially what the designer was trying to do, and just making the parts to fit accurately. If the designer comes in all hoity toity pretending he's the end-all of audio, a machinist might simply give you the parts to print and let you stew in your own failure.
Nah, it's just a string of rf cavities with a high Q. For acceleration, it'll generally be a fixed frequency but the cavities will be larger and longer as the beam progresses because of the velocity.
jn
For the record, Constellation is now with NEAL FEAY. The son of the guy took over, and we (I hope) are getting pretty good and consistent product. 30 years has passed since the first problems with the metal work. I had little or nothing to do with the design or the dimensions of the case, in the beginning. I hired a mechanical engineer when I still had some problems. I just was left to 'cry' when the cases did not fit together. IF that is an 'end-all of audio' position, then I am guilty. If you are just trying to insult me, you are doing a pretty good job.
At the beginning of my professional life, i was designing products (amps, turntables, speakers enclosures) produced by hundreds a day.
In a way, it is easier, because the providers takes care, considering the amount of business, in an other way, you have a big responsability, as any error can have huge consequences, stopping production lines.
We had, too, a lot of problems with sheet metal tolerances. Little by little, had learned how to get rid of that, like quoting our plans from an unique well choose reference point and sign very detailed and restrictive contracts.
This said, look how a single DIYER can build a well designed and good looking amplifier, all by himself:
http://www.diyaudio.com/forums/solid-state/193923-simple-symetrical-amplifier-101.html#post2922615
http://www.diyaudio.com/forums/solid-state/193923-simple-symetrical-amplifier-107.html#post2952612
http://www.diyaudio.com/forums/solid-state/193923-simple-symetrical-amplifier-76.html#post3007067
We were talking cases. As I said by hand .005", sheet metal finished about the same to .015". Machined (not ground) .001" on modern equipment, WWII era .005", Ground .0005"-.0002" are what I would call typical. Now with aluminum or a bit less as temperature really counts and quickly machined to size it will shrink a bit.
Now hobbiest milled .01" ! But what kind of tolerance can you get on a 100 foot long milled piece of 7075?
(We aren't really in disagreement!)
The reviewers say it's positively toe tapping, right up there with the MBL-6010D. What's that old eight legs still good for something?
Simon,
Glad we could agree on something. I assume you are using a turret press for production of sheet metal parts. Yes it is funny how people talk about tolerances on parts that long on one of these gantry milling machines. They often aren't in temperature controlled environments so the ambient temperature is going to change all the dimensions. I have had to argue when someone wanted to change the inspection method on tooling that was produced over 30 years ago and they want to change from a theodolite inspection to laser tracker. All of the tooling would have been rejected if we did that.
Glad we could agree on something. I assume you are using a turret press for production of sheet metal parts. Yes it is funny how people talk about tolerances on parts that long on one of these gantry milling machines. They often aren't in temperature controlled environments so the ambient temperature is going to change all the dimensions. I have had to argue when someone wanted to change the inspection method on tooling that was produced over 30 years ago and they want to change from a theodolite inspection to laser tracker. All of the tooling would have been rejected if we did that.
Try 3 meter long alum tubes where it's 98 degrees F room temperature, and the coolant fluid isn't temperature controlled.
jn
Isn't that device too analytical for toe tapping 
. I still think you only designed it to trick AD into building you a better phono pre-amp.I like it in that position btw.
New widget from TI
http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=tps7a4700&fileType=pdf
Would be nice to have an adapter board for TTH.
. I still think you only designed it to trick AD into building you a better phono pre-amp.I like it in that position btw.New widget from TI
http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=tps7a4700&fileType=pdf
Would be nice to have an adapter board for TTH.
Isn't that device too analytical for toe tapping
New widget from TI
http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=tps7a4700&fileType=pdf
Would be nice to have an adapter board for TTH.
What a funny spec to trumpet: 4.17uV noise. And not 10 nV more! Still, happy to see it.
Actually I didn't think we disagreed on much. I got my first drill press before I was 10. I do have a "journeyman" machinist who works for me part time keeping the tooling sharp.
On the weekend, went to use a chisel and only found one undamaged. Need to have a chat with my guys about that. One fellow made a custom grill for his guitar amp with just the .159" punch doing graphics and letters!
So this week there is a lot to clean and sharpen!
George,
I reran the ripple test and got more of what I was expecting.
Attached is an FFT showing a CRC of 1000 uF 1 ohm 4700 uF and then reversed 4700 uF 1 ohm 1000 uF. Almost exactly the same.
The big Duh moment was when I tried a 4700 uF 1 ohm 4700 uf against a triple 4700 uF 1 ohm 4700 uF 1 ohm 4700 uF. Results that stood out.
The other issue was capacitor brand. The cheapies had the same results for the first few harmonics but were no where as good at the upper ranges! So now I have to order in samples of all the common brands!
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Steve, we generally don't do prints, we submit dxf files. The CNC crew has no problem holding tolerances, and my engineers are pretty good at making one material fit another. Then again, we don't do fashion audio, we make stuff that has to perform in high end factories and top test labs, day in and day out, no excuses.
The real secret is the machining fluids, of course.
The real secret is the machining fluids, of course.
Ed
What was the source of noise in your previous measurement?
Before start ordering bags with capacitors, try to test what happens with these 3 psu setups when the load is not a simple passive resistor.
Connect them to supply power to a small amplifier.
Feed a freq sweep to amplifier input.
Do this at 3 power levels low, medium, high. Probe the psu rails.
Then spell some #@%!! on me
(I am not in a good mood)
George
Sy,
I'm afraid if I give someone my Solidworks file I have to cut a mold with a dxf file that there are going to be some real problems as I haven't been able to get the part as one complete solid. I think the cutter path is going to be a mess when it tries to transition from one section to another. I haven't worked on trying to merge the sections lately, the error I get is that the two section are allowing a zero thickness section. Not easy to fix on a complex surface shape such as I have done. I haven't learned MasterCam yet but think I am going to have to do that to make the design CNC compatible. G-code is what I think most machinist are wanting these days.
I'm afraid if I give someone my Solidworks file I have to cut a mold with a dxf file that there are going to be some real problems as I haven't been able to get the part as one complete solid. I think the cutter path is going to be a mess when it tries to transition from one section to another. I haven't worked on trying to merge the sections lately, the error I get is that the two section are allowing a zero thickness section. Not easy to fix on a complex surface shape such as I have done. I haven't learned MasterCam yet but think I am going to have to do that to make the design CNC compatible. G-code is what I think most machinist are wanting these days.
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