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post #166 of 170
9/1/08 at 5:01pm
Quote:
Originally Posted by digger945 View Post
Jade, if I give you the photos or images, you can superimpose them all together? How about the "original" plus cable a plus cable b (three images)?
I can probably do 3 it's only going to be a quick photoshop job so it's not going to be "lab standard" or anything

I do think you're going to need a good way to sync the recordings.
Here is the old school way the "2 pop". You're going to have to recreate a file that has a short burst tone before the song starts. In a waveform editor you can the place the pop on the same place time-wise by lining up the bursts. It should give you a reference to work with at least.

In video/film a one frame burst is often used to sync picture and non timecode audio and going way back the "clapper" slates were used to sync sound to picture.

I made a short clip that you can use here to see if it will work for you.
(using a short snip from the wonder full Pharoah Sanders track "the creator has a master plan" from the priceless collection cd that everyone should run out and buy)

Your Big File

Again I think you should do multiple recordings of the individual cables to
see how much noise and randomness is in the graphics.
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post #167 of 170
9/2/08 at 6:34pm
Here is another comparison using schOPE VST plugin for Pyro with the Nano as source, the white line is the solid silver wire and the pink line is the cryo.
The first image is the two recordings at about 1millisecond apart, so none of the sine waves come close to lining up....


The second image below you will see the two signals almost perfectly overlapped.


The signal is a 10kHz test tone that obviously has five different amplitudes that repeat. It is very noticable in digital stairstepped form (analog shown here).
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post #168 of 170
9/2/08 at 6:49pm
I should say that the first comparison I posted is flawed. While trying to repeat the test I decided to monitor the music with headphones and discovered that the drivers for iTunes and Pyro dont exactly "mesh" to good. This is why I decided to go ahead and start experimenting, so that by failing I will evertually learn a better way. I will be deleting that post this evening. I really think that I must have an external measurement device to perform future tests. I also discovered that the picoscope I had thought about purchasing does not superimpose recordings per thier website.

kw, square waves are next
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post #169 of 170
9/3/08 at 2:39pm
Quote:
Originally Posted by digger945 View Post
I should say that the first comparison I posted is flawed. While trying to repeat the test I decided to monitor the music with headphones and discovered that the drivers for iTunes and Pyro dont exactly "mesh" to good. This is why I decided to go ahead and start experimenting, so that by failing I will evertually learn a better way. I will be deleting that post this evening. I really think that I must have an external measurement device to perform future tests. I also discovered that the picoscope I had thought about purchasing does not superimpose recordings per thier website.

kw, square waves are next

You're going to need to use a much higher resolution (higher sweep speed) in order to see anything truly revealing. One cycle maximum, and more likely, only a fraction of a cycle and focus in on the knee of the curve. Good luck!!
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post #170 of 170
9/3/08 at 4:11pm
Quote:
Originally Posted by kwkarth View Post
You're going to need to use a much higher resolution (higher sweep speed) in order to see anything truly revealing. One cycle maximum, and more likely, only a fraction of a cycle and focus in on the knee of the curve. Good luck!!

What do you think about starting off with something like what amb(Ti Kan) uses to evaluate his amps? He uses the Protek 6510 100MHz analog oscilloscope with a Wavetek 188 4MHz sweep function generator. Do you think that this will give us a decent start? Maybe Ti will give us a little insight into equipment selection and/or his own testing methods.
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