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26 minutes ago, CWRNH said:

What would be the best shielded cable and connectors to use? 

Would ground planes for the grounds and v- lessen or worsen the noise?

I would look around for an old pair of wired headphones that are no longer in use, cut the cable off, and use that.  Typically they are shielded and very flexible.

I doubt you would be able to measure a difference with or without the copper pour.  If I were making the pcb myself, I always use copper pour to make my etchant last longer! 

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1 hour ago, CWRNH said:

Do you know of a less elaborate amp with better results? 

I am quite sure.

1 hour ago, CWRNH said:

Please share

I already did to some extent ?.
However I do not use WOS or its amplifier. Maybe its developer can contribute a bit more here, as he is reading, too.

Frank

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49 minutes ago, CWRNH said:

I have a couple questions.

Should I have used ceramic capacitors for instead of film capacitors?  (I used the film type because they were what I had on hand, I had to combine 2 C1s and 3 C7s to get the correct values).  I read that sometimes the ceramic capacitors can act like mics so I thought the film type may be better.

Would I 9.6v power source be okay to use with this circuit?  I want to use a rechargeable higher capacity battery.

What would be the best shielded cable and connectors to use? 

Would ground planes for the grounds and v- lessen or worsen the noise?

I don't think the kind of capacitors matter for the coupling capacitors. (Everyone  seems to use ceramic for bypass capacitors, though.) I investigated microphonics in my circuit and I don't think I found anything. Don't really remember.

Higher voltage definitely works. It's a weak 9 V battery that causes trouble. And based on praezis's comment, I think I will use a 12 V battery from now on (A23 batteries are readily available).

I am using RG174/U coax as my shielded cable. The local electronics store calls it "instrument cable."  The most important thing is to put the board in a metal box. Shielding the microphone itself makes a difference to the noise spectrum, but I don't know if this affects actual operation any.

I don't know about the ground planes, but a problem with my layout is that there are  no good places to put the bypass capacitors. I think for an analog circuit  like this with no high-current switching going on, this is probably not that critical. (I wonder if the rail-splitter has any switching circuitry.)

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1 hour ago, wlysenko said:

Higher voltage definitely works. It's a weak 9 V battery that causes trouble

It depends upon the choice of your op amp. For instance the circuit I have I'm powering it off the USB port because I don't like batteries.

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4 hours ago, praezis said:

I am quite sure.

I already did to some extent ?.
However I do not use WOS or its amplifier. Maybe its developer can contribute a bit more here, as he is reading, too.

Frank

Sorry, I don't remember seeing it.  I thought I read everything but there is a lot of posts in this thread.

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1 hour ago, JohnR725 said:

It depends upon the choice of your op amp. For instance the circuit I have I'm powering it off the USB port because I don't like batteries.

I had problems with AC hum, this is why I decided to stick with battery power.  If I know of a way to create a power circuit that would automatically charge a 9.6v battery and still allow the use of the device, while not introducing 60 cycle hum, I would use it.  If anyone can point me in a direction of how to accomplish this I would love to try it and report back the results.

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7 minutes ago, CWRNH said:

I had problems with AC hum,

I would have to see where I actually soldered the wires to steal the power. I'm not actually plugged into the USB port I'm using a USB microphone headphone adapter. This way I'm using that as the microphone input and swiping the power for my  circuit.

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3 hours ago, wlysenko said:

I don't think the kind of capacitors matter for the coupling capacitors. (Everyone  seems to use ceramic for bypass capacitors, though.) I investigated microphonics in my circuit and I don't think I found anything. Don't really remember.

Higher voltage definitely works. It's a weak 9 V battery that causes trouble. And based on praezis's comment, I think I will use a 12 V battery from now on (A23 batteries are readily available).

I am using RG174/U coax as my shielded cable. The local electronics store calls it "instrument cable."  The most important thing is to put the board in a metal box. Shielding the microphone itself makes a difference to the noise spectrum, but I don't know if this affects actual operation any.

I don't know about the ground planes, but a problem with my layout is that there are  no good places to put the bypass capacitors. I think for an analog circuit  like this with no high-current switching going on, this is probably not that critical. (I wonder if the rail-splitter has any switching circuitry.)

Do you know what element is used in the Vibrograph pickup?  I think the B200 and B200a are different.   If I remember right one was very subseptable to moisture and often destroyed over time.  Mine seems very solid and works great, I would like to purchase just the element and build a mic but I have not been able to find much on the web, especially the technical specs.  The Vibrograph mic element is completely encased in an aluminum housing, it is attached to a pronged rest that is insulated and tightly fitted to the casing.  The shielded wire attaches to an elaborate swivel system the connects to the mic element with very fine wires.  I think the combination of how the shielded cable connects to the base, and how the fine wires attach to the mic, may have a large positive effect because sound and vibrations from the environment are not as easily transferred from the  physical cable to the mic.  Also the mic is shielded inside aluminum.  

I cannot hear background sounds like cars or talking when listening through the AMP using the vibrograph mic but I certainly can with the regular piezo disc type mic.

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7 minutes ago, LittleWatchShop said:

Enclose it in a metal box (as someone suggested), and ground the box to earth ground.  I have mine in open air sitting on a metal desk.  If the metal desk is not grounded, I have problems with ac hum.

The other machine I made is totally enclosed inside a metal enclosure but I still get a lot of noise.  My (Real timing machines) get a lot of noise too.  This latest one is the best so far, it is the only one not plugged into the wall.  I probably have some issue with the wiring in my shop.  When I built my CNC mill I had a lot of trouble with ground loops and EMF, I finally worked it all out for the most part but occasionally the VFD I used to run my spindle would cause problems so I detached it from my motion controller and just set the speed manually, problem solved.  I used chokes and high quality connectors and I have a filter on my mains.

I have TONS of fluorescent lights and other electronics running in the shop so I am surprised I can get any AMP to work.

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4 hours ago, praezis said:

I am quite sure.

I already did to some extent ?.
However I do not use WOS or its amplifier. Maybe its developer can contribute a bit more here, as he is reading, too.

Frank

I don't use the amp from WOS but I do use the software, and E-timer also.  Both are excellent.  I have several other timing software apps including the one you showed in your post.  This amp I built is based on the WOS but several things have been added and changed.  I built the original WOS first, It is about the same as the other amps I have, it works but is noisy in my environment.  The WOS amp is better than the pro timing machines I have in many respects.   Even Witschi and the cheap Chinese ones are not all that much better (if at all) than the combination of amp and software I am using now.  After nearly 30 years I have used many types and brands of timing machines, this is why I decided to make my own.  Not to save money but to gain functionality and ease of use.

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6 minutes ago, LittleWatchShop said:

BTW @CWRNH, I suggest adding extra ground pads to your layout as well as V- and V+.  This is for test only.  You may want to attach scope probe ground and need a good test point to connect it to.

Great idea.  As you know I am very new to all this stuff.  I am surprised I was able to get anything working.

Thanks.

 

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Should I space the components out more on the board?  I read in the TI data sheets that keeping the whole thing compact was often a good idea..

The original board was a breadboard so there is only so much real estate to work with.

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4 hours ago, praezis said:

Do you know of a less elaborate amp with better results? 

Well, I will dare to speak of the humble transistor.
I put the images and audio files together with the clock from which I obtained the sound. Nothing else is needed. The circuit is made up of a transistor and a resistor. Plug directly into your computer's sound input and you're done. The recording is raw, it has no filter of any kind.
And fluorescent light definitely makes too much noise. But this should be located at 50 or 60 Hz. The ones I have been able to hear in your recordings are from transformers or power supplies for computers. It could be that the fluorescent lights use an electronic ballast.

1076655948_MicTransistor(2).thumb.JPG.d76ca4f792ad37b700a5c5e9814b65d1.JPG

IMG_20210319_142110859.thumb.jpg.b019cbe54d29e33c9a1045c3a418302c.jpg

IMG_6754.thumb.JPG.7b5324131302a26f3618ed9ee7bd5fab.JPG

1076655948_MicTransistor(2).thumb.JPG.d76ca4f792ad37b700a5c5e9814b65d1.JPG

Transistor.mp3

Audio Config.

1769589159_ConfituracindeAudio.thumb.JPG.2c311df50ba3d690c1ee6615a397dd8e.JPG

 

IMG_Transisitor Mic.jpg

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4 minutes ago, guidovelasquez said:

Well, I will dare to speak of the humble transistor.
I put the images and audio files together with the clock from which I obtained the sound. Nothing else is needed. The circuit is made up of a transistor and a resistor. Plug directly into your computer's sound input and you're done. The recording is raw, it has no filter of any kind.
And fluorescent light definitely makes too much noise. But this should be located at 50 or 60 Hz. The ones I have been able to hear in your recordings are from transformers or power supplies for computers. It could be that the fluorescent lights use an electronic ballast.

1076655948_MicTransistor(2).thumb.JPG.d76ca4f792ad37b700a5c5e9814b65d1.JPG

IMG_20210319_142110859.thumb.jpg.b019cbe54d29e33c9a1045c3a418302c.jpg

IMG_6754.thumb.JPG.7b5324131302a26f3618ed9ee7bd5fab.JPG

1076655948_MicTransistor(2).thumb.JPG.d76ca4f792ad37b700a5c5e9814b65d1.JPG

Transistor.mp3 391.84 kB · 0 downloads

Audio Config.

1769589159_ConfituracindeAudio.thumb.JPG.2c311df50ba3d690c1ee6615a397dd8e.JPG

 

IMG_Transisitor Mic.jpg

That is awesome...  I will build one too and report the results.  Can't use the alligator clip but I will use with the Vibrograph mic.   If it is quieter than the fancy amp that I just spent weeks screwing with, I will overjoyed with the amount of time I spent on my new educational experience....

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16 minutes ago, CWRNH said:

Should I space the components out more on the board? 

I would.  This is not a 5G transceiver you are dealing with.  Take a look at the Vibrograph unit...you are much smaller than that.  Spreading out the components just makes later troubleshooting easier.  Replacing a capacitor for a different value...etc.

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18 minutes ago, guidovelasquez said:

Well, I will dare to speak of the humble transistor.
I put the images and audio files together with the clock from which I obtained the sound. Nothing else is needed. The circuit is made up of a transistor and a resistor. Plug directly into your computer's sound input and you're done. The recording is raw, it has no filter of any kind.
And fluorescent light definitely makes too much noise. But this should be located at 50 or 60 Hz. The ones I have been able to hear in your recordings are from transformers or power supplies for computers. It could be that the fluorescent lights use an electronic ballast.

1076655948_MicTransistor(2).thumb.JPG.d76ca4f792ad37b700a5c5e9814b65d1.JPG

IMG_20210319_142110859.thumb.jpg.b019cbe54d29e33c9a1045c3a418302c.jpg

IMG_6754.thumb.JPG.7b5324131302a26f3618ed9ee7bd5fab.JPG

1076655948_MicTransistor(2).thumb.JPG.d76ca4f792ad37b700a5c5e9814b65d1.JPG

Transistor.mp3 391.84 kB · 2 downloads

Audio Config.

1769589159_ConfituracindeAudio.thumb.JPG.2c311df50ba3d690c1ee6615a397dd8e.JPG

 

IMG_Transisitor Mic.jpg

Pocket watch sez: "Ouch."

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33 minutes ago, guidovelasquez said:

Well, I will dare to speak of the humble transistor.
I put the images and audio files together with the clock from which I obtained the sound. Nothing else is needed. The circuit is made up of a transistor and a resistor. Plug directly into your computer's sound input and you're done. The recording is raw, it has no filter of any kind.
And fluorescent light definitely makes too much noise. But this should be located at 50 or 60 Hz. The ones I have been able to hear in your recordings are from transformers or power supplies for computers. It could be that the fluorescent lights use an electronic ballast.

1076655948_MicTransistor(2).thumb.JPG.d76ca4f792ad37b700a5c5e9814b65d1.JPG

IMG_20210319_142110859.thumb.jpg.b019cbe54d29e33c9a1045c3a418302c.jpg

IMG_6754.thumb.JPG.7b5324131302a26f3618ed9ee7bd5fab.JPG

1076655948_MicTransistor(2).thumb.JPG.d76ca4f792ad37b700a5c5e9814b65d1.JPG

Transistor.mp3 391.84 kB · 2 downloads

Audio Config.

1769589159_ConfituracindeAudio.thumb.JPG.2c311df50ba3d690c1ee6615a397dd8e.JPG

 

IMG_Transisitor Mic.jpg

https://en.wikipedia.org/wiki/Madman_Muntz

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48 minutes ago, guidovelasquez said:

Well, I will dare to speak of the humble transistor.
I put the images and audio files together with the clock from which I obtained the sound. Nothing else is needed. The circuit is made up of a transistor and a resistor. Plug directly into your computer's sound input and you're done. The recording is raw, it has no filter of any kind.
And fluorescent light definitely makes too much noise. But this should be located at 50 or 60 Hz. The ones I have been able to hear in your recordings are from transformers or power supplies for computers. It could be that the fluorescent lights use an electronic ballast.

1076655948_MicTransistor(2).thumb.JPG.d76ca4f792ad37b700a5c5e9814b65d1.JPG

IMG_20210319_142110859.thumb.jpg.b019cbe54d29e33c9a1045c3a418302c.jpg

IMG_6754.thumb.JPG.7b5324131302a26f3618ed9ee7bd5fab.JPG

1076655948_MicTransistor(2).thumb.JPG.d76ca4f792ad37b700a5c5e9814b65d1.JPG

Transistor.mp3 391.84 kB · 2 downloads

Audio Config.

1769589159_ConfituracindeAudio.thumb.JPG.2c311df50ba3d690c1ee6615a397dd8e.JPG

 

IMG_Transisitor Mic.jpg

Works with the piezo mic but not with the vibrograph.  Almost no signal with the vibrograph mic.  With the piezo mic it pics up my breathing and every sound in the room.  But definitely is a usable setup.  My piezo mic is not a clip on so it would probably work better if I had it set up like yours.  I cannot use alligator type clips for regular watch work.  It picked up the 18 size PW but got almost nothing from the 2892 movement.

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I wonder if a more modern approach would work better.

Use a modern microphone designed for picking up voice through bone conduction, such as Bone Conductor Sensor – Analog Piezoelectric MEMS Voice Accelerometer

Or use a microphone array, like this one from MiniDSP.  The array allows for beamforming: determining where sound is coming from.  This way external sounds can be rejected because it's possible to determine they didn't originate from the movement, rather than filtering based on frequency, which is unable to filter noise at the same frequency as the movement's sounds.

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7 hours ago, guidovelasquez said:

Well, I will dare to speak of the humble transistor.
I put the images and audio files together with the clock from which I obtained the sound. Nothing else is needed. The circuit is made up of a transistor and a resistor. Plug directly into your computer's sound input and you're done. The recording is raw, it has no filter of any kind.
And fluorescent light definitely makes too much noise. But this should be located at 50 or 60 Hz. The ones I have been able to hear in your recordings are from transformers or power supplies for computers. It could be that the fluorescent lights use an electronic ballast.

1076655948_MicTransistor(2).thumb.JPG.d76ca4f792ad37b700a5c5e9814b65d1.JPG

IMG_20210319_142110859.thumb.jpg.b019cbe54d29e33c9a1045c3a418302c.jpg

IMG_6754.thumb.JPG.7b5324131302a26f3618ed9ee7bd5fab.JPG

1076655948_MicTransistor(2).thumb.JPG.d76ca4f792ad37b700a5c5e9814b65d1.JPG

Transistor.mp3 391.84 kB · 2 downloads

Audio Config.

1769589159_ConfituracindeAudio.thumb.JPG.2c311df50ba3d690c1ee6615a397dd8e.JPG

 

IMG_Transisitor Mic.jpg

Another try with the Transistor amp and the circuit I am working on compared.

First the circuit I made.  Then the Transistor amp.  While I was recording i moved an small object around on my bench opposite the mic.  Fairly high gain.  Val7750 movement.

My circuit

OpAmp circuit no filter Val7750.m4aimage.thumb.png.8693377baa8d84212dbed0bbf1349b5a.png

 

Now the Transistor Amp.

Transistor amp no filter val7750.m4a

image.thumb.png.99d2930c6bdfc0657e311ad2a907b38b.png

 

So again, it definitely works and probably would get better results with a better mic.  It pics up lots of background sounds also as you can hear on the recording.  I did the same routine for both recordings with both amps.

I wonder if a combination of your idea and opamps would work?  I wonder why it did not work with the vibrograph mic?

So while I was writing this I decided to try the microset clip on mic with the transistor amp, here is the result below.

image.thumb.png.66e17111229e36ba1932cbc86c66daec.png

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6 minutes ago, xyzzy said:

I wonder if a more modern approach would work better.

Use a modern microphone designed for picking up voice through bone conduction, such as Bone Conductor Sensor – Analog Piezoelectric MEMS Voice Accelerometer

Or use a microphone array, like this one from MiniDSP.  The array allows for beamforming: determining where sound is coming from.  This way external sounds can be rejected because it's possible to determine they didn't originate from the movement, rather than filtering based on frequency, which is unable to filter noise at the same frequency as the movement's sounds.

Looks cool, great for voice, but I don't think it would work with watch movements.

image.thumb.png.d11c3f8ab1c95358364c5b7a965b8f56.png

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