LOL.
Hey, I am listening to my stereo fitted with a No Name Quantum Purifier right now..... I am still perfectly intact, and so is my stereo.
Anybody know where I can get a flux capacitor.....
Dan.
I have been thinking about this problem, generally when I have to get a reasonably high current from one layer to another the best way to do it is to use multiple small vias, in an array. The plating down the barrel of any hole should be of good quality and should be the same as the copper foil only 20-25microns thick, that said it is one of the areas of PCB manufacture where total commitment to quality is paramount, the problem is that things seem to be slipping as a recent report by Printed Circuit Design and Fabrication has highlighted:
Printed Circuit Design & Fab Online Magazine - PCB Fabrication Processes and Their Effects on Fine Copper Barrel Cracks
This is worrying because this problem (PTH plating) was a cause of many failures and problems in the late 80's that I had hoped had gone away, obviously not.
If you can ask your supplier for a micro section across a PTH hole, some suppliers do it as a QA check when doing batches of boards and are often willing to supply them, this does vary and with more and more cheap sources of PCB fabricators appear and outsourcing from known supplies increases I think that these quality issues are going to appear. So I would suspect bad plating in your case, the use of multiple smaller vias should help mitigate some of the problems, if you give it a go I would be interested in any differences found in measurements between different designs.
Oh ! May-be that's why i measure this jitter in my local space-time continuum ?
! Jitter cannot be recorded, thus it cannot inter-modulate with the jitter at the DAC.
Not the way a lot of these "improvements" are implemented... Some real measurements would be interesting and probably very enlightening to many who believe that these mods are a benefit, they MAY be if done correctly, but the majority I see are just going to add problems.
Perhaps you misunderstand me.
Imagine a tape recorder with capstan speed variation (jitter) recording a pure tone.
Now play that tape back with no capstan speed variation.
The reproduced resultant will be a pure tone with frequency modulation....ie the capstan speed variation (jitter) is effectively recorded (encoded).
Now play that tape again with a different capstan speed variation.
The reproduced output tone will now contain the effects of two capstan speed variations (jitters).
Capisce?.
Sure. It is assumed in this discussion that the implementation is correct/ideal.
Dan.
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OK that makes a difference. Let me think about how to go about this. Indeed the dScope can do it I believe.
Jan
OK, dScope can generate a digital stream with a user-defined peak-to-peak jitter, so that can be my source. I think we are interested in the degradation of the analog output of a DAC, right? So I can do an FFT on the DAC output and vary the input jitter, is that the kind of thing we are looking for?
Jan
Is this a reference to the famous JKenny thread....... Hi-Face vs. Sy's cheap Chinese alternative etc. All subjective of course!
Speaking of P&G, guess what?
They're no longer making the rotary faders. Found this out about a month ago.
se
dScope III......Envious.
There are numerous eBay $20.00 DAC boards with both coax and Toslink inputs.
Comparison of coax and Toslink SPDIF feeds might be interesting.
Dan.
Some DAC chips (ESS IIRC) claim to attenuate incoming data jitter.....you may need to try various outboard SPDIF connected DACs.
There are numerous eBay $20.00 DAC boards with both coax and Toslink inputs.
Comparison of coax and Toslink SPDIF feeds might be interesting.
Useful machine....what did it cost ?.
Dan.
As Dan pointed out, you can get them from Acoustic Dimension. But they're actually made by another company. I'll PM you.
se
Even easier, just record the test signal on a CD, make a copy of a copy of a copy. Measure all for jitter and see if there is any change.
The expert opinion is that they should all be the same.
For more fun you can make copies at 2x, 4x, etc.
That should put to rest the growth in jitter theory.
Of course if you pick for a sample some good dance music you can always do the jitter-bug.
ES
Yeah, he's a bit quirky, but I found the Goldpoint to be better than the DACT.
I built a headphone amp for a friend. He originally wanted to use a DACT. It was a balanced input amp so he needed a 4 deck switch. When the switch arrived, it was so loose you could barely feel the indents. DACT was using much too loose of a spring.
So I bought a 4 deck from Goldpoint. It was perfect.
se
Considering the amount of PTH holes done everyday, this is not a problem... There are many other problems associated with the formation PT Holes, which are well documented and catered for in fabrication, I wont go into details as there are already enough perceived gremlins in Audio without adding more to the list.
As said there are billions of plated holes on millions of products that work, carrying critical, non-critical sensitive, high speed and analogue signals with no distortion or problems, but as my previous post showed things can go wrong.....
Here are some pretty pictures with references to the IPC specs that will give you more information.
PWB microsection gallery - Element
This should also be interesting:
Eurocircuits - Making a PCB - PCB Manufacture step by step
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