Mic adapter to connect Witschi to computer?

jguitron · February 26, 2017

Hello everyone,

I was wondering if anyone has any experience or at least heard of finding a converter so that the microphone stand from a Watch Expert machine can be plugged to a computer. I recently got my hands on a Witschi. It has great fidelity and the mic is excellent. I have been using WOS for some time now and I really like it, but the shortfall is the mic.

So, I did some search of a possible adapter to connect the mic to the computer and use WOS. The mic has a 5 pin plug. I couldn't find much...

Thanks in advance!

JG

rodabod · February 26, 2017

Can you photograph the plug? May be a 5-pin DIN.

jguitron · February 27, 2017

On 2/26/2017 at 11:14 PM, rodabod said:

Can you photograph the plug? May be a 5-pin DIN.

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Yes!

here it is. Thank you!

jguitron · February 27, 2017

Upload failed... will try at computer. Sorry

jguitron · February 27, 2017

On 2/26/2017 at 11:14 PM, rodabod said:

Can you photograph the plug? May be a 5-pin DIN.

Expand

Here! Finally...

rodabod · February 27, 2017

Yeah, that's a 5-pin DIN.

If the mics are passive then they would likely only use two of the five terminals. Will need to try and find a schematic which shows the "pin out" for the Witschi mic cable in order to find out how to wire an adapter cable. I will have a look, but do post one if you find one.

rodabod · February 27, 2017

I can't find a diagram, but if you don't have one either then you may be able to figure it out using a multimeter.

jguitron · February 27, 2017

On 2/27/2017 at 7:33 AM, rodabod said:
I can't find a diagram, but if you don't have one either then you may be able to figure it out using a multimeter.

Well I decided to go for it and give it a shot. A long shot.

Identifying the plug was very helpful, now I got a couple cables and adaptors coming my way. I'll report back either way.

Thanks much!

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rodabod · February 27, 2017

Should be able to identify two pins which carry the audio signal by using a multimeter. I think piezo transducers usually measure in the K.Ohm range. This assumes it is passive and does not contain a preamp.

rodabod · February 27, 2017

Other alternative is set your multimeter to measure AC and connect across every permutation of pairs of pins and tap the mic to see if you can get a response.

robmack · February 27, 2017

The older mikes used salt crystals and not modern piezo elements. Resistance should be about 1.8KOhms.

teegee · March 1, 2017

Would it really not have a preamp in the stand? Even my cheap Chinese timegrapher uses a preamp. You could still hook it up to a PC (I plan to try WOS as well), but you'd need some minimal external electronics to provide power to the pramp.

robmack · March 1, 2017

The output from the vibration sensor on the stand is too low for the PC to use without preamplification. If you were to increase the sensitivity of the microphone input on the PC to compensate for the low signal, it would also boost the noise. The signal would not be usable. I would suggest reading the thread on this forum about the Watch-o-scope project. There is an amplifier design published by Stefan which others have built for the purpose of boosting the signal from a Witschi mike for use on a PC. There is a suggestion by one of the contributors for an off the shelf amp that also works. I built Stefan's amp and attached my Vibrograf B200 watch stand to it; it works marvelously well.

rodabod · March 1, 2017

On 3/1/2017 at 2:54 AM, teegee said:

Would it really not have a preamp in the stand? Even my cheap Chinese timegrapher uses a preamp. You could still hook it up to a PC (I plan to try WOS as well), but you'd need some minimal external electronics to provide power to the pramp.

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I think most PC mic inputs will be able to provide power (albeit at a low voltage) to allow headsets with electret microphones to work. Adds another layer of complexity when trying to figure out how the mics are wired on timegraphers though.

I think checking the watch-o-scope thread is a good suggestion as above.

jguitron · March 1, 2017

On 3/1/2017 at 3:05 AM, robmack said:
The output from the vibration sensor on the stand is too low for the PC to use without preamplification. If you were to increase the sensitivity of the microphone input on the PC to compensate for the low signal, it would also boost the noise. The signal would not be usable. I would suggest reading the thread on this forum about the Watch-o-scope project. There is an amplifier design published by Stefan which others have built for the purpose of boosting the signal from a Witschi mike for use on a PC. There is a suggestion by one of the contributors for an off the shelf amp that also works. I built Stefan's amp and attached my Vibrograf B200 watch stand to it; it works marvelously well.

Quick update: I received the adapters and was able to connect the Witschi mic into the preamp just like I have been using it with the other mic with just ok results. The amp is transmitting ok, I can see the big jump in the waveform when I tap on it. But just like @tobmack said, the signal is too weak and when I increase the preamp it boost the noise as well. Quickly compared with the clip on Korg mic and it had a discernible waveform.

This was all quick and dirty because of time restraints, I'll post pics asap.

Thanks for your input!

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