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Thank you PeterM. I am not an expert but I can say that something can be applied.
GPS can be used to calibrate the Watch-O-Scope software. It would be much more accurate than what is achieved with a good quality quartz watch.
The sensor also attracts attention although you cannot see what it is.
Thanks for sharing.

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Thanks Stefan.  I must say this is a super bit of software, much more versatile than any timing machine I've seen.  I made a lashup microphone stand to get me going, with the intention of making a "proper" one after a few weeks.  That was over 2 years ago and I still haven't made the "proper" one.  Also the only quad op amp in my bits box was an LM349, which is quite hissy but the software manages to filter out the signal from all the noise just fine.  Very useful, I wouldn't be without it.

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Hi guys,

I have been following along as best that I can on this issue.

I do have a few questions and I am hoping that somebody can enlighten me.

I think that the cradle to mount the watch in is pretty simple to build. It looks like that part has been mastered.

 

The part that seems difficult is the mic and amp.

I see that people have mostly settled on a Piezo/contact mic.

As for the pre-amp.....has anybody considered a headphone amp?  

I am imagining the Piezo/contact mic plugged into the input of a headphone amp...with the output plugged into the mic input of a laptop or desktop.  I understand why a regular amp might be an issue...but you can get audiophile quality out and headphone amps do not put out much power. 

Maybe there is a good reason why this will not work and I do not know what it is.

But I can see a person grabbing...say...... a Schiit Modi 1 or 2 used off of Ebay. The cable can be some RG6 coax (Which is shielded 16 gauge wire) and just put connectors on the ends.

I see a lot of people want to build ......so maybe they would build a Cmoy amp? Again, this is a headphone amp...but very clean and runs on a 9v.

As I understand it...(Knowing that I do not have the musical background of many on here)...essentially a pre-amp is just an amp..but on a much weaker scale. )

I have considered this setup....but before I started shelling out money, I thought I would ask a few people who are much farther along in this than myself if I am considering something that simply will not work.

 

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There's a big difference between a preamp and a headphone amp. In the simplest terms, a preamp takes a very weak signal (or in the case of a watch mic, a very very very weak signal) and turns it into just a weak signal. A headphone amp turns a weak signal into a strong signal.

Amplifiers also do impedance matching. A piezo element's impedance is primarily capacitive (around 27pF for the one I use), whereas a sound card's input impedance is resistive, typically around 10kΩ. A suitable preamp has corresponding input and output impedances. A headphone amplifier on the other hand takes a signal with about a 10kΩ impedance and converts it to a stronger signal with a much lower impedance, typically around 8Ω to 32Ω.

Thus, a preamp is primarily a voltage amplifier to boost a weak signal, and a headphone amp is primarily a current amplifier to drive the low impedance of the headphones.

The Schiit amp you mention has a selectable voltage gain of 0dB or 5.5dB (1x to 1.8x). The amplifier used by Watch-O-Scope has a gain 75dB (about 5600x). So they're not at all similar.

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Bien venido @MatteoB, pienso que tu entusiasmo es justificado.  El programa es sencillamente maravilloso.   Tanto para los que conocen de relojería como para los que simplemente admiramos los relojes relojes mecánicos.  Qué parte del funcionamiento del programa te parece más fascinante?

 

Welcome @MatteoB, I think your enthusiasm is justified. The program is simply wonderful. Both for those who know watchmaking and for those who simply admire mechanical watches. What part of the operation of the program do you find most fascinating?

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16 minutes ago, jdm said:

May I make you aware that we have a dedicated section where it's considered polite for new members to introduce themselves before asking questions. 

Sorry, I forgot to do it. I'll add my presentation as soon as possible! Thank you

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9 minutes ago, guidovelasquez said:

Bien venido @MatteoB, pienso que tu entusiasmo es justificado.  El programa es sencillamente maravilloso.   Tanto para los que conocen de relojería como para los que simplemente admiramos los relojes relojes mecánicos.  Qué parte del funcionamiento del programa te parece más fascinante?

 

Welcome @MatteoB, I think your enthusiasm is justified. The program is simply wonderful. Both for those who know watchmaking and for those who simply admire mechanical watches. What part of the operation of the program do you find most fascinating?

I'm particularly interested in how, from a simple sound wave it is be able to obtain such precision and what type of algorithm is he using. He wrote about digital noise reduction, what filter is it using? Do you computer a Fourier Transform? 

 

Thank you in advice

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I will give you my explanation as a perfect layman.
First the nature of the clock sound. If we want to see it like this, the waveform or spectrogram of the clock sound is very simple. It is well within the frequency limits of the human audible spectrum. In fact most of us can hear the ticking of the clock quite well as we approach one in a quiet room.
The important thing about this is that the tic-tac is made up of 3 important sounds and very different in terms of time and intensity. The program, using a complex algorithm, makes it possible to locate these 3 sounds perfectly, thus obtaining the spectrogram to analyze the performance of the clock.
About the algorithm, my knowledge limits what I can inform you. But by the behavior of the program, I can say that it is extremely efficient.
On the other hand, it is important to mention that sound capture is a key part. A microphone with particular characteristics is required. It is actually a vibration sensor. In other words, it must capture the mechanical vibrations that travel inside the watch and its case without hardly registering the ambient noise.
Something I can add based on my experience is that the software is capable of extracting useful information for analysis from poor or poor sound. I encourage you to watch the next video at this link.

 

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2 hours ago, MatteoB said:

Thank you for your work @svorkoetter. Can you explain the algorithm please? I'm really interested. How do you get the exact starting point of the tick from the sound wawe? 

Hi @MatteoB, this forum probably isn't the place to get into such details, but very briefly, the input is first filtered (if filtering is enabled) using a 4th order infinite impulse response bandpass filter. After that, the software tracks an envelope of the signal, looking for the three distinct sounds making up each tick (as mentioned by @guidovelasquez). The time of the start of each sound is recorded, and the watch performance computed from those. Statistical analysis is applied to all the ticks within the averaging period. This, together with the initial filtering, is what produces stable results even when the signal is noisy. FFTs are not used.

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I came across this watch microphone on eBay, and was wondering if anyone has seen, or tried one before. It comes in two versions, one with a stand that can be rotated in different positions. The other version is just a rectangular box. They appear to be made out of plastic and maybe 3D printed. The seller says that the rectangular box version contains a 3.7V rechargeable battery and the version with the stand works with a 9 volt battery. I ordered the version with the stand and will test it out as soon as I receive it. You can find it by searching for "TGB watch Calibration" in eBay.

 

 

Watch.jpg

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4 minutes ago, jamez361 said:

They appear to be made out of plastic and maybe 3D printed. The seller says that the rectangular box version contains a 3.7V rechargeable battery and the version with the stand works with a 9 volt battery. I ordered the version with the stand and will test it out as soon as I receive it. You can find it by searching for "TGB watch Calibration" in eBay.

In my opinion its price of about €60 is not competitive against the the original, metal made item.
https://www.aliexpress.com/item/32764684610.html 

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The price difference is indeed not much, however the thing that drew me to this one is it appears to have a built in amplifier already. So you only need a 3.5mm audio cable and you are all set.

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1 minute ago, jamez361 said:

The price difference is indeed not much, however the thing that drew me to this one is it appears to have a built in amplifier already. So you only need a 3.5mm audio cable and you are all set.

Even the metal one has a pre-amp, one just has to supply power and adapt the cable as explained in the previous postings.
 

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1 hour ago, jdm said:

Even the metal one has a pre-amp, one just has to supply power and adapt the cable as explained in the previous postings.

If you look carefully at the pictures on eBay it's definitely 3-D printed. It's an interesting design idea they sort of cloned the Chinese microphone and 3-D print it. The circuitry is probably different in that they either have 9 V or a 3.7 V battery running the thing. Ill be interesting to see what it looks like inside as soon as someone gets one. But the advantage is it's all put together. As a reminder not everybody has the skill set to wire up or even solder anything.

 

 

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10 hours ago, JohnR725 said:

As a reminder not everybody has the skill set to wire up or even solder anything.

Well, one that repair watches himself should certainly be as to solder such a simple cable.  While a collector can easily have it made. 

As mentioned before I think the best value is had buying a model 1000 to use for the 98% of the time, and then use its microphone with a PC and software for more sophisticated analysis, which is only occasionally necessary. 

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On 7/6/2014 at 8:43 PM, svorkoetter said:

I'm a watch DIYer, having serviced two watches myself, partially using tools of my own making. One thing I've been working on over the last few months is my own PC based timing machine. I've finally got something working reliably, and thought I'd preview it here. My plan is to eventually write up a detailed article on my web site describing how to build the hardware, and providing a download for the software. I may also produce a "pro" version of the software with more features, to be sold for a reasonable fee.

 

Here's the hardware, all home made of course:

 

post-140-0-26666800-1404692988_thumb.jpg

 

The next picture shows the timing trace from my "Black Lagoon", a modified Invicta 8926OB with a Seiko NH35A movement (yes, the amplitude is quite low and tends to fluctuate, topping out around 220 degrees - apparently this is par for the course for Seiko movements):

 

post-140-0-18039200-1404693024_thumb.jpg

 

In this picture, the software is in scope mode, showing directly the ticks and tocks. Notice how with this movement, they alternate in loudness. Since the scope mode was run after the timing mode, the scope also shows the threshold that was used by the timing mode to detect the start of each tick.

 

post-140-0-90022000-1404693014_thumb.jpg

 

And this is the settings window:

 

post-140-0-71980600-1404693245_thumb.jpg

 

Here's a brief list of features so far (I have to resist creeping featuritis):

I believe that in Silicon Valley featuritis is normally a software glitch that marketing puts forward as a “feature” rather than a problem i.e Microsoft reboots randomly is an automatic updating feature not a memory glitch! 

On 7/6/2014 at 8:43 PM, svorkoetter said:
  • Numerical display of daily rate error, balance amplitude, and beat error.
  • Horizontal "paper tape" mode with sub-pixel vertical resolution that can show fluctuations that are too small to see on a typical stand-alone timing machine.
  • User selectable averaging period.
  • Rate determination using linear least squares, which gives a more meaningful reading than just naively averaging the rate.
  • Automatic signal and noise level determination. There's nothing to adjust.
  • Aggressive noise filtering in the software to keep the hardware simple.
  • Automatic rate detection for common rates.
  • Simple, uncluttered, fixed-size display (1024x600).
  • Scope mode to aid in diagnosis of various watch faults.

 

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14 hours ago, GeorgeB said:

I believe that in Silicon Valley featuritis is normally a software glitch that marketing puts forward as a “feature” rather than a problem i.e Microsoft reboots randomly is an automatic updating feature not a memory glitch! 

You quoted my entire original post from 6 years ago, pictures and all, to add this (incorrect) bit of information?!? Hint: I've been a professional software developer for 31 years.

Quote

Featuritis, Creeping featurism or the spoonerism Feeping Creaturism, is a term used to describe software which over-emphasizes new features to the detriment of other design goals, such as simplicity, compactness, stability, or bug reduction.

https://lmgtfy.com/?q=featuritis

Edited by svorkoetter

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