[Tutorial] Building your own DIY E-Stim Stereo Device

[lolol2]

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Electric play can be dangerous!
Please check healthy information about e-stim before you start!
Everything is on your own risk!
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V2 Version I would recommend to look at! -> Link
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Hello stimer and people who are interested in that kind of topic!

I want to leave a little tutorial to build a kind of simple estim stereo device because this forum is still lacking a bit of useful information about that topic. An own build device is still the cheapest way to get into that "hobby" and those devices are really powerful and can handle all kind of signals.

This tutorial shows my own device which I'm very happy with... possible that there are more smarter and better designs out there. Just want to share one more idea because when you search for that stuff and have not very deep knowledge in electronics, a lot of posts/tutorials will blow your mind.
So I tried to keep this very simple.

I will also add a shopping list for all parts you need, I'm living in Germany, so all those parts are linked to German online shops, but everything are basic electronical parts and should be available all over the world.

This tutorial doesn't offer the easiest way for a DIY unit, you should have some basic knowledge in electronics and be able to soldering some cables/components together.
But you don't have to been an electrician for this! I also have only very basic skills, you can see on the pics attached.

For your own safety only follow this tutorial if you feel safe to handle some electric DIY stuff.


Lets start with the shopping list:

1x Case to fit everything inside - 12,94€
1x 2 x 35W stereo AMP - 28,26€
1x Cooler for the AMP - 4,36€
2x 100V voltage transformers - 12,28€
2x 1k Ohm high load resistance - 6,80€
2x 10k Ohm Pots - 3,02€
2x Volume buttons for pots - 7,26€
2x Power switch (power + triphase) - 2,62€
1x Power connector for power supply - 3,18€
2x Cinch connector - 6,98€ (choose two different colors)
4x Ports for electrodes - 8,92€ (choose 2x black + 2x different colors)
2x 5m 1,5mm² cable - 8,14€ (pick red + black)

1x 12V power supply - 29,99€ (120W is maybe not needed, but can recommend this one)
For safety reasons make sure to pick one that is double insulated and has some good quality, don't buy cheap ones without any declaration about that!
Looks like Leicke changed there production and this one isn't anymore a class 2!

Of course this device could also be powered by a 12V battery which is also a safe way.

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Total: 124,75 €


Symbol for double insulated power supplies, square inside a square.

1477491291class2.jpg (49.7 KiB) Viewed 52308 times

Next you only need to know how to wire those components up... here you go, I have created a hopefully simple plan.
(the resolution is higher if you open the pic right click -> open picture)

Don't forget to add the triphase switch, trust me you will like it and this will save some complex external wires.




Here are some example pics of my box... as said I'm not expert in this topic and this could look way better but the important part is that it's working.







Top left = Left channel
Bottom left = right channel
Top right = Cinch stereo computer audio input
Bottom right = Triphase switch


Maybe that will help someone who is looking for a device at the moment.
Feel free to leave some feedback, infos or questions.

[alexfayer]

That is absolutely amazing lolol2! Exactly what I was searching for. The triphase switch was something I also wanted to put into the design as it's so easy to add.

I will order the parts today and will post pictures when I finished building it. ;)

Thank you so much for this!

[mantrid]

Hi,

the left hand side can be purchased for a fraction of the price, e.g. at there. Make sure it has a balance knob (otherwise you have to use computers mixer for that), a 12V power supply input and an output rating of about 15W at a load of 4 Ohm. (Power of a +/- 11V sinus signal)

Consideration for output circuit can be found in this post viewtopic.php?p=268506#p268506. Also see the following posts for schematics, more part numbers (Reichelt+Digikey), a photo and some calculation.

[lolol2]

@alexfayer
Excited to see the results and hear the feedback about how it feels.
If you fit this amp in a very small case a few little drilling holes for air circulation can't be bad, because the cooler can get hot.
Oh and of course don't forget the cooler!

@mantrid
Yes definitely not the cheapest and easiest way to build a DIY unit, but wanted to share my design with a complete detail part list and diagram.
So everyone can "easy" duplicate it without the need of searching hours in the internet for which parts to add/combine.

About the low pass frequency filter, I never used one and never had problems, but I guess I just never tried to play very low FQs, you know when the FQ is way to deep very quick because the power/feeling is way stronger and sharper.

This device is designed to play estim audio files and not playing music or other unfiltered stuff into your body.

[ZeeWW]

Wow this is great... I think even I might be able to make this. What are the orange blocks that connect all the wires? I don't see them in your shopping list?

Thanks.

Ah I zoomed in they are lever cable connectors

[mantrid]

About the low pass frequency filter, I never used one

I hope so. I recommend a high pass filter.

and never had problems, but I guess I just never tried to play very low FQs, you know when the FQ is way to deep very quick because the power/feeling is way stronger and sharper.

I do not know how that feels because never tried it out.

Some people think it's a good idea to use these low (carrier) frequencies for pain effects and some tease authors recommend self bondage, see this thread for example.

This device is designed to play estim audio files and not playing music or other unfiltered stuff into your body.

That design does nothing else than playing unfiltered stuff into your body.

You either have to rely on people writing save estim files or you have to rely that you feel when it becomes unhealthy.

(And you have to decide whether it is worth it to save one or two bucks ...)

[lolol2]

Ah right mixed up the function of low/high pass filters...
Any recommendation of parts and an example how to add them to this design for a high pass filter?

And no matter what device you have, I would never recommend to do selfbondage with any signals you don't know 100%.

[mantrid]

All information can be found in the thread I mentioned aove.

I tried to collect the most importand posts:

• Reichelt part numbers and initial description
• Shematics
• Digikey part numbers filter calculation
• Review of the Digikey transformer and photo of the output circuit

Part dimensioning

First of all, the resistor should be on the input side of the transformer. Theoretically a resistor of size R at the output side is equivalent to resistor of size R/n² at the input side if n is the winding ratio. But we do not want to transform the power for the resistor due to transformer limitations. Furthermore a resistor on input side is independent from winding ratio. So, chose a 10 to 20 Ohm resistor and place it as shown in the schematics.

The consensus is that the a perfect output is current controlled. This is achieved best by choosing high transformation ratios and large series resistors. But both choices reduce the power that is transformed. So it has to be tried out. (Smallest winding number on input side is between 4 Ohm and 8 Ohm: 18. Highest winding number at output side is between 0W and 0.625W: 2900. See the datasheet)

Third issue is capacitor selection . If you use it only with fixed carrier frequency estim files, chose it as stated in the links above: 100µF + 10 Ohm or 47µF + 20 Ohm. But recently estim teases with variable frequency appeared. They might work better with a lower cut-off frequency -- that is difficult to predict.

So my recommendation:
Low cut-off frequency option: 100µF + 20 Ohm or 220µF + 10 Ohm
High cut-off frequency option: 100µF + 10 Ohm
In both cases, highest winding ratio that deliver sufficient power should be used.

[alexfayer]

Mantrid that is very detailed information thank you!

However I am now lost again. I do not know electronics as much as I thought I did. How do I add these safety features into the shematic above what lolol2 provided? Could you maybe change the given shematic and draw your additions into it with the component sizes? This would help a lot.

[lolol2]

I have the same problem... too many sources, too many technical information I can't fully understand.
Also need a more direct information with a simple example which part would fit into this design.

That's why I wanted to provided this "simple" but detailed plan which shows exactly what you need and how to connect the parts.
Most examples getting really fast to technical and most people (like me) are more confused than it helped.

[lolol2]

If you are only stimming with your computer and have a separate soundcard for your estim device you can easily use a software to filter all frequencies of this audio device.

Like with EqualizerAPO

I'm using this software already for my speakers, so I just added a little rule for my estim soundcard.

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[ZeeWW]

Would someone please take the schematic that lolo2 has provide and in pictures with the name of the parts, show the low pass filter and how it is wired up?

Then we can all start soldering and safely enjoy this rig.

Thanks

[mantrid]

I flipped the photo and redraw the circuit diagram such that components now appear as on the photo.

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Resistor (blue thing), transformer (red box) side with lower winding number and capacitor must be in series. The TVS diode (black cylinder, protects against malfunction of the power supply) should be parallel to capacitor and transformer.

The cables on the left hand side are connected to the amplifier, the cables on the right hand side are connected to electrodes.

In lolo2's drawing the circuit shown above replaces the transformer and the golden series resistor, i.e. the banana jacks have to be connected directly to the transformer and the resistor+capacitor+TVS diode has to be inserted between transformer an amplifier.

For my device I simply soldered circuits as photographed, isolated them with heat shrink tubings and connected them to banana jacks (right-hand side) and the output of readily boxed amplifiers with volume and balance knob (left-hand side). That's all, safe and simple.

[alexfayer]

It took me some time to understand this. I put my thoughts into the shematic lolol2 posted and changed it.
Hopefully this is correct mantrid?

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[mantrid]

Hopefully this is correct mantrid?

It is correct. The new winding selection should be tested. If it is to weak (if the output impedance becomes to large) a lower winding ratio should be used.